subscription base logic

2026-03-22 17:23:54 +01:00 · 2026-03-22 17:23:54 +01:00 · c813bd63ca
commit c813bd63ca
parent 9186c60ad2
24 changed files with 2722 additions and 129 deletions
--- a/app.py
+++ b/app.py
@ -601,6 +601,9 @@ app.include_router(gdprRouter)
 from modules.routes.routeBilling import router as billingRouter
 app.include_router(billingRouter)

+from modules.routes.routeSubscription import router as subscriptionRouter
+app.include_router(subscriptionRouter)
+
 # ============================================================================
 # SYSTEM ROUTES (Navigation, etc.)
 # ============================================================================
--- a/config.ini
+++ b/config.ini
@ -44,3 +44,8 @@ Connector_StacSwisstopo_TIMEOUT = 30
 Connector_StacSwisstopo_MAX_RETRIES = 3
 Connector_StacSwisstopo_RETRY_DELAY = 1.0
 Connector_StacSwisstopo_ENABLE_CACHE = True
+
+# Operator company information (shown on invoice emails)
+Operator_CompanyName = PowerOn AG
+Operator_Address = Birmensdorferstrasse 94, 8003 Zürich
+Operator_VatNumber = CHE491.960.195
--- a/modules/datamodels/datamodelBilling.py
+++ b/modules/datamodels/datamodelBilling.py
@ -143,6 +143,9 @@ class BillingSettings(BaseModel):
    )
    warningThresholdPercent: float = Field(default=10.0, description="Warning threshold as percentage")
    
+    # Stripe
+    stripeCustomerId: Optional[str] = Field(None, description="Stripe Customer ID (cus_xxx) — one per mandate")
+
    # Notifications (e.g. mandate owner / finance — also used when PREPAY_MANDATE pool is exhausted)
    notifyEmails: List[str] = Field(
        default_factory=list,
@ -163,6 +166,7 @@ registerModelLabels(
            "de": "Startguthaben nur Root-Mandant (CHF)",
        },
        "warningThresholdPercent": {"en": "Warning Threshold (%)", "de": "Warnschwelle (%)"},
+        "stripeCustomerId": {"en": "Stripe Customer ID", "de": "Stripe-Kunden-ID"},
        "notifyEmails": {
            "en": "Billing notification emails (owner / admin)",
            "de": "E-Mails für Billing-Alerts (Inhaber/Admin)",
@ -260,12 +264,15 @@ class BillingStatisticsResponse(BaseModel):


 class BillingCheckResult(BaseModel):
-    """Result of a billing balance check."""
+    """Result of a billing balance check (budget + subscription gate)."""
    allowed: bool
    reason: Optional[str] = None
    currentBalance: Optional[float] = None
    requiredAmount: Optional[float] = None
    billingModel: Optional[BillingModelEnum] = None
+    upgradeRequired: Optional[bool] = None
+    subscriptionUiPath: Optional[str] = None
+    userAction: Optional[str] = None


 def parseBillingModelFromStoredValue(raw: Optional[str]) -> BillingModelEnum:
--- a/modules/datamodels/datamodelSubscription.py
+++ b/modules/datamodels/datamodelSubscription.py
@ -0,0 +1,235 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""Subscription models: SubscriptionPlan (catalog), MandateSubscription (instance per mandate),
+StripePlanPrice (persisted Stripe IDs per plan).
+
+State Machine: see wiki/concepts/Subscription-State-Machine.md
+"""
+
+from typing import Dict, List, Optional
+from enum import Enum
+from datetime import datetime, timezone
+from pydantic import BaseModel, Field
+from modules.shared.attributeUtils import registerModelLabels
+import uuid
+
+
+class SubscriptionStatusEnum(str, Enum):
+    """Lifecycle status of a mandate subscription.
+    See wiki/concepts/Subscription-State-Machine.md for transition rules."""
+    PENDING = "PENDING"
+    SCHEDULED = "SCHEDULED"
+    TRIALING = "TRIALING"
+    ACTIVE = "ACTIVE"
+    PAST_DUE = "PAST_DUE"
+    EXPIRED = "EXPIRED"
+
+
+TERMINAL_STATUSES = {SubscriptionStatusEnum.EXPIRED}
+OPERATIVE_STATUSES = {SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.TRIALING, SubscriptionStatusEnum.PAST_DUE}
+
+ALLOWED_TRANSITIONS = {
+    (SubscriptionStatusEnum.PENDING, SubscriptionStatusEnum.ACTIVE),
+    (SubscriptionStatusEnum.PENDING, SubscriptionStatusEnum.SCHEDULED),
+    (SubscriptionStatusEnum.PENDING, SubscriptionStatusEnum.EXPIRED),
+    (SubscriptionStatusEnum.SCHEDULED, SubscriptionStatusEnum.ACTIVE),
+    (SubscriptionStatusEnum.SCHEDULED, SubscriptionStatusEnum.EXPIRED),
+    (SubscriptionStatusEnum.TRIALING, SubscriptionStatusEnum.EXPIRED),
+    (SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.PAST_DUE),
+    (SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.EXPIRED),
+    (SubscriptionStatusEnum.PAST_DUE, SubscriptionStatusEnum.ACTIVE),
+    (SubscriptionStatusEnum.PAST_DUE, SubscriptionStatusEnum.EXPIRED),
+}
+
+
+class BillingPeriodEnum(str, Enum):
+    """Recurring billing interval."""
+    MONTHLY = "MONTHLY"
+    YEARLY = "YEARLY"
+    NONE = "NONE"
+
+
+# ============================================================================
+# Catalog: SubscriptionPlan (static, in-memory)
+# ============================================================================
+
+class SubscriptionPlan(BaseModel):
+    """Plan definition (catalog entry). Not stored per mandate — static."""
+    planKey: str = Field(..., description="Unique plan identifier")
+    selectableByUser: bool = Field(default=True, description="Whether users can choose this plan in the UI")
+
+    title: Dict[str, str] = Field(default_factory=dict, description="Multilingual title (en/de/fr)")
+    description: Dict[str, str] = Field(default_factory=dict, description="Multilingual description")
+
+    currency: str = Field(default="CHF", description="Billing currency")
+    billingPeriod: BillingPeriodEnum = Field(default=BillingPeriodEnum.MONTHLY, description="Recurring interval")
+    pricePerUserCHF: float = Field(default=0.0, description="Price per active user per period")
+    pricePerFeatureInstanceCHF: float = Field(default=0.0, description="Price per active feature instance per period")
+    autoRenew: bool = Field(default=True, description="Stripe renews automatically at period end")
+
+    maxUsers: Optional[int] = Field(None, description="Hard cap on active users (None = unlimited)")
+    maxFeatureInstances: Optional[int] = Field(None, description="Hard cap on active feature instances (None = unlimited)")
+    trialDays: Optional[int] = Field(None, description="Trial duration in days (only for trial plans)")
+    successorPlanKey: Optional[str] = Field(None, description="Plan to transition to when trial ends")
+
+
+registerModelLabels(
+    "SubscriptionPlan",
+    {"en": "Subscription Plan", "de": "Abonnement-Plan", "fr": "Plan d'abonnement"},
+    {
+        "planKey": {"en": "Plan", "de": "Plan", "fr": "Plan"},
+        "selectableByUser": {"en": "Selectable", "de": "Wählbar", "fr": "Sélectionnable"},
+        "billingPeriod": {"en": "Billing Period", "de": "Abrechnungszeitraum", "fr": "Période de facturation"},
+        "pricePerUserCHF": {"en": "Price per User (CHF)", "de": "Preis pro User (CHF)"},
+        "pricePerFeatureInstanceCHF": {"en": "Price per Instance (CHF)", "de": "Preis pro Instanz (CHF)"},
+        "maxUsers": {"en": "Max Users", "de": "Max. Benutzer", "fr": "Max. utilisateurs"},
+        "maxFeatureInstances": {"en": "Max Instances", "de": "Max. Instanzen", "fr": "Max. instances"},
+    },
+)
+
+
+# ============================================================================
+# Stripe Price mapping (persisted in DB, auto-created at bootstrap)
+# ============================================================================
+
+class StripePlanPrice(BaseModel):
+    """Persisted mapping from planKey to Stripe Product/Price IDs.
+    Auto-created at startup — no manual configuration needed.
+    Uses separate Stripe Products for users and instances for clear invoice labels."""
+    id: str = Field(default_factory=lambda: str(uuid.uuid4()), description="Primary key")
+    planKey: str = Field(..., description="Reference to SubscriptionPlan.planKey")
+    stripeProductId: str = Field("", description="Legacy single-product ID (unused)")
+    stripeProductIdUsers: Optional[str] = Field(None, description="Stripe Product ID for user licenses")
+    stripeProductIdInstances: Optional[str] = Field(None, description="Stripe Product ID for feature instances")
+    stripePriceIdUsers: Optional[str] = Field(None, description="Stripe Price ID for user-seat line item")
+    stripePriceIdInstances: Optional[str] = Field(None, description="Stripe Price ID for instance line item")
+
+
+registerModelLabels(
+    "StripePlanPrice",
+    {"en": "Stripe Plan Prices", "de": "Stripe-Planpreise"},
+    {
+        "planKey": {"en": "Plan", "de": "Plan"},
+        "stripeProductIdUsers": {"en": "Product (Users)", "de": "Produkt (User)"},
+        "stripeProductIdInstances": {"en": "Product (Instances)", "de": "Produkt (Instanzen)"},
+        "stripePriceIdUsers": {"en": "Price ID (Users)", "de": "Preis-ID (User)"},
+        "stripePriceIdInstances": {"en": "Price ID (Instances)", "de": "Preis-ID (Instanzen)"},
+    },
+)
+
+
+# ============================================================================
+# Instance: MandateSubscription
+# ============================================================================
+
+class MandateSubscription(BaseModel):
+    """A subscription instance bound to a specific mandate.
+    See wiki/concepts/Subscription-State-Machine.md for state transitions."""
+    id: str = Field(default_factory=lambda: str(uuid.uuid4()), description="Primary key")
+    mandateId: str = Field(..., description="Foreign key to Mandate")
+    planKey: str = Field(..., description="Reference to SubscriptionPlan.planKey")
+
+    status: SubscriptionStatusEnum = Field(default=SubscriptionStatusEnum.PENDING, description="Current lifecycle status")
+    recurring: bool = Field(default=True, description="True: auto-renews at period end. False: expires at period end (gekuendigt).")
+
+    startedAt: datetime = Field(default_factory=lambda: datetime.now(timezone.utc), description="Record creation timestamp")
+    effectiveFrom: Optional[datetime] = Field(None, description="When this subscription becomes operative. None = immediate. Set for SCHEDULED subs.")
+    endedAt: Optional[datetime] = Field(None, description="When subscription ended (terminal)")
+    currentPeriodStart: Optional[datetime] = Field(None, description="Current billing period start (synced from Stripe)")
+    currentPeriodEnd: Optional[datetime] = Field(None, description="Current billing period end (synced from Stripe)")
+    trialEndsAt: Optional[datetime] = Field(None, description="Trial expiry timestamp")
+
+    snapshotPricePerUserCHF: float = Field(default=0.0, description="Price snapshot at activation (for invoice history)")
+    snapshotPricePerInstanceCHF: float = Field(default=0.0, description="Price snapshot at activation")
+
+    stripeSubscriptionId: Optional[str] = Field(None, description="Stripe Subscription ID (sub_xxx)")
+    stripeItemIdUsers: Optional[str] = Field(None, description="Stripe Subscription Item ID for user seats")
+    stripeItemIdInstances: Optional[str] = Field(None, description="Stripe Subscription Item ID for feature instances")
+
+
+registerModelLabels(
+    "MandateSubscription",
+    {"en": "Mandate Subscription", "de": "Mandanten-Abonnement", "fr": "Abonnement du mandat"},
+    {
+        "id": {"en": "ID", "de": "ID"},
+        "mandateId": {"en": "Mandate ID", "de": "Mandanten-ID"},
+        "planKey": {"en": "Plan", "de": "Plan"},
+        "status": {"en": "Status", "de": "Status"},
+        "recurring": {"en": "Recurring", "de": "Wiederkehrend"},
+        "startedAt": {"en": "Started", "de": "Gestartet"},
+        "effectiveFrom": {"en": "Effective From", "de": "Wirksam ab"},
+        "endedAt": {"en": "Ended", "de": "Beendet"},
+        "currentPeriodStart": {"en": "Period Start", "de": "Periodenbeginn"},
+        "currentPeriodEnd": {"en": "Period End", "de": "Periodenende"},
+        "trialEndsAt": {"en": "Trial Ends", "de": "Trial endet"},
+        "snapshotPricePerUserCHF": {"en": "Price/User (CHF)", "de": "Preis/User (CHF)"},
+        "snapshotPricePerInstanceCHF": {"en": "Price/Instance (CHF)", "de": "Preis/Instanz (CHF)"},
+    },
+)
+
+
+# ============================================================================
+# Built-in plan catalog (static, no env dependency)
+# ============================================================================
+
+BUILTIN_PLANS: Dict[str, SubscriptionPlan] = {
+    "ROOT": SubscriptionPlan(
+        planKey="ROOT",
+        selectableByUser=False,
+        title={"en": "Root (System)", "de": "Root (System)", "fr": "Root (Système)"},
+        description={"en": "Internal system plan — no billing.", "de": "Interner Systemplan — keine Verrechnung."},
+        billingPeriod=BillingPeriodEnum.NONE,
+        autoRenew=False,
+        maxUsers=None,
+        maxFeatureInstances=None,
+    ),
+    "TRIAL_7D": SubscriptionPlan(
+        planKey="TRIAL_7D",
+        selectableByUser=False,
+        title={"en": "Free Trial (7 days)", "de": "Gratis-Testphase (7 Tage)", "fr": "Essai gratuit (7 jours)"},
+        description={
+            "en": "Try the platform for 7 days — 1 user, up to 3 feature instances.",
+            "de": "Plattform 7 Tage testen — 1 User, bis zu 3 Feature-Instanzen.",
+        },
+        billingPeriod=BillingPeriodEnum.NONE,
+        autoRenew=False,
+        maxUsers=1,
+        maxFeatureInstances=3,
+        trialDays=7,
+        successorPlanKey="STANDARD_MONTHLY",
+    ),
+    "STANDARD_MONTHLY": SubscriptionPlan(
+        planKey="STANDARD_MONTHLY",
+        selectableByUser=True,
+        title={"en": "Standard (Monthly)", "de": "Standard (Monatlich)", "fr": "Standard (Mensuel)"},
+        description={
+            "en": "Usage-based billing per active user and feature instance, billed monthly.",
+            "de": "Nutzungsbasierte Abrechnung pro aktivem User und Feature-Instanz, monatlich.",
+        },
+        billingPeriod=BillingPeriodEnum.MONTHLY,
+        pricePerUserCHF=90.0,
+        pricePerFeatureInstanceCHF=150.0,
+    ),
+    "STANDARD_YEARLY": SubscriptionPlan(
+        planKey="STANDARD_YEARLY",
+        selectableByUser=True,
+        title={"en": "Standard (Yearly)", "de": "Standard (Jährlich)", "fr": "Standard (Annuel)"},
+        description={
+            "en": "Usage-based billing per active user and feature instance, billed yearly.",
+            "de": "Nutzungsbasierte Abrechnung pro aktivem User und Feature-Instanz, jährlich.",
+        },
+        billingPeriod=BillingPeriodEnum.YEARLY,
+        pricePerUserCHF=1080.0,
+        pricePerFeatureInstanceCHF=1800.0,
+    ),
+}
+
+
+def _getPlan(planKey: str) -> Optional[SubscriptionPlan]:
+    """Resolve a plan by key from the built-in catalog."""
+    return BUILTIN_PLANS.get(planKey)
+
+
+def _getSelectablePlans() -> List[SubscriptionPlan]:
+    """Return plans that users can choose in the UI."""
+    return [p for p in BUILTIN_PLANS.values() if p.selectableByUser]
--- a/modules/features/workspace/routeFeatureWorkspace.py
+++ b/modules/features/workspace/routeFeatureWorkspace.py
@ -19,6 +19,9 @@ from modules.auth import limiter, getRequestContext, RequestContext
 from modules.serviceCenter.services.serviceBilling.mainServiceBilling import (
    InsufficientBalanceException,
 )
+from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+    SubscriptionInactiveException,
+)
 from modules.interfaces import interfaceDbChat, interfaceDbManagement
 from modules.interfaces.interfaceAiObjects import AiObjects
 from modules.serviceCenter.core.serviceStreaming import get_event_manager
@ -803,7 +806,15 @@ async def _runWorkspaceAgent(
        })

    except Exception as e:
-        if isinstance(e, InsufficientBalanceException):
+        if isinstance(e, SubscriptionInactiveException):
+            logger.warning(f"Workspace blocked by subscription: {e.message}")
+            await eventManager.emit_event(queueId, "error", {
+                "type": "error",
+                "content": e.message,
+                "workflowId": workflowId,
+                "item": e.toClientDict(),
+            })
+        elif isinstance(e, InsufficientBalanceException):
            logger.warning(f"Workspace blocked by billing: {e.message}")
            await eventManager.emit_event(queueId, "error", {
                "type": "error",
--- a/modules/interfaces/interfaceBootstrap.py
+++ b/modules/interfaces/interfaceBootstrap.py
@ -103,6 +103,13 @@ def initBootstrap(db: DatabaseConnector) -> None:
    if mandateId:
        initRootMandateBilling(mandateId)

+    # Initialize subscription for root mandate
+    if mandateId:
+        _initRootMandateSubscription(mandateId)
+
+    # Auto-provision Stripe Products/Prices for paid plans (idempotent)
+    _bootstrapStripePrices()
+

 def initAutomationTemplates(dbApp: DatabaseConnector, adminUserId: Optional[str] = None) -> None:
    """
@ -2069,6 +2076,47 @@ def initRootMandateBilling(mandateId: str) -> None:
        logger.warning(f"Failed to initialize root mandate billing (non-critical): {e}")


+def _initRootMandateSubscription(mandateId: str) -> None:
+    """
+    Ensure the root mandate has an active ROOT subscription.
+    Called during bootstrap after billing init.
+    """
+    try:
+        from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+        from modules.datamodels.datamodelSubscription import (
+            MandateSubscription,
+            SubscriptionStatusEnum,
+        )
+
+        subInterface = getSubRootInterface()
+        existing = subInterface.getOperativeForMandate(mandateId)
+        if existing:
+            logger.info("Root mandate subscription already exists")
+            return
+
+        sub = MandateSubscription(
+            mandateId=mandateId,
+            planKey="ROOT",
+            status=SubscriptionStatusEnum.ACTIVE,
+            recurring=False,
+        )
+        subInterface.createSubscription(sub)
+        logger.info("Created ROOT subscription for root mandate")
+
+    except Exception as e:
+        logger.warning(f"Failed to initialize root mandate subscription (non-critical): {e}")
+
+
+def _bootstrapStripePrices() -> None:
+    """Auto-create Stripe Products and Prices for all paid plans.
+    Idempotent — safe on every startup. IDs are persisted in the StripePlanPrice table."""
+    try:
+        from modules.serviceCenter.services.serviceSubscription.stripeBootstrap import bootstrapStripePrices
+        bootstrapStripePrices()
+    except Exception as e:
+        logger.error(f"Stripe price bootstrap failed (subscriptions will not work for paid plans): {e}")
+
+
 def assignInitialUserMemberships(
    db: DatabaseConnector, 
    mandateId: str, 
--- a/modules/interfaces/interfaceDbApp.py
+++ b/modules/interfaces/interfaceDbApp.py
@ -1616,6 +1616,9 @@ class AppObjects:
            if existing:
                raise ValueError(f"User {userId} is already member of mandate {mandateId}")

+            # Subscription capacity check (before insert)
+            self._checkSubscriptionCapacity(mandateId, "users", delta=1)
+
            # Create UserMandate
            userMandate = UserMandate(
                userId=userId,
@ -1637,6 +1640,9 @@ class AppObjects:
            # Create billing account for user if billing is configured
            self._ensureUserBillingAccount(userId, mandateId)

+            # Sync Stripe quantity after successful insert
+            self._syncSubscriptionQuantity(mandateId)
+
            cleanedRecord = {k: v for k, v in createdRecord.items() if not k.startswith("_")}
            return UserMandate(**cleanedRecord)
        except Exception as e:
@ -1686,6 +1692,28 @@ class AppObjects:
        except Exception as e:
            logger.warning(f"Failed to create billing account for user {userId} (non-critical): {e}")

+    def _checkSubscriptionCapacity(self, mandateId: str, resourceType: str, delta: int = 1) -> None:
+        """Check subscription capacity before creating a resource. Raises on cap violation."""
+        try:
+            from modules.interfaces.interfaceDbSubscription import getInterface as getSubInterface
+            from modules.security.rootAccess import getRootUser
+            subIf = getSubInterface(getRootUser(), mandateId)
+            subIf.assertCapacity(mandateId, resourceType, delta)
+        except Exception as e:
+            if "SubscriptionCapacityException" in type(e).__name__:
+                raise
+            logger.debug(f"Subscription capacity check skipped: {e}")
+
+    def _syncSubscriptionQuantity(self, mandateId: str) -> None:
+        """Sync Stripe subscription quantities after a resource mutation."""
+        try:
+            from modules.interfaces.interfaceDbSubscription import getInterface as getSubInterface
+            from modules.security.rootAccess import getRootUser
+            subIf = getSubInterface(getRootUser(), mandateId)
+            subIf.syncQuantityToStripe(mandateId)
+        except Exception as e:
+            logger.debug(f"Subscription quantity sync skipped: {e}")
+
    def deleteUserMandate(self, userId: str, mandateId: str) -> bool:
        """
        Delete a UserMandate record (remove user from mandate).
--- a/modules/interfaces/interfaceDbSubscription.py
+++ b/modules/interfaces/interfaceDbSubscription.py
@ -0,0 +1,353 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Interface for Subscription operations — ID-based, deterministic.
+
+Every write operation takes an explicit subscriptionId.
+No status-scan guessing. See wiki/concepts/Subscription-State-Machine.md.
+"""
+
+import logging
+from typing import Dict, Any, List, Optional
+from datetime import datetime, timezone
+
+from modules.connectors.connectorDbPostgre import DatabaseConnector
+from modules.shared.configuration import APP_CONFIG
+from modules.datamodels.datamodelUam import User
+from modules.datamodels.datamodelMembership import UserMandate
+from modules.datamodels.datamodelSubscription import (
+    SubscriptionPlan,
+    MandateSubscription,
+    SubscriptionStatusEnum,
+    BillingPeriodEnum,
+    ALLOWED_TRANSITIONS,
+    TERMINAL_STATUSES,
+    OPERATIVE_STATUSES,
+    BUILTIN_PLANS,
+    _getPlan,
+    _getSelectablePlans,
+)
+
+logger = logging.getLogger(__name__)
+
+SUBSCRIPTION_DATABASE = "poweron_billing"
+
+_subscriptionInterfaces: Dict[str, "SubscriptionObjects"] = {}
+
+
+class InvalidTransitionError(Exception):
+    """Raised when a state transition is not allowed by the state machine."""
+    def __init__(self, subscriptionId: str, fromStatus: str, toStatus: str):
+        self.subscriptionId = subscriptionId
+        self.fromStatus = fromStatus
+        self.toStatus = toStatus
+        super().__init__(f"Invalid transition {fromStatus} -> {toStatus} for subscription {subscriptionId}")
+
+
+def getInterface(currentUser: User, mandateId: str = None) -> "SubscriptionObjects":
+    cacheKey = f"{currentUser.id}_{mandateId}"
+    if cacheKey not in _subscriptionInterfaces:
+        _subscriptionInterfaces[cacheKey] = SubscriptionObjects(currentUser, mandateId)
+    else:
+        _subscriptionInterfaces[cacheKey].setUserContext(currentUser, mandateId)
+    return _subscriptionInterfaces[cacheKey]
+
+
+def _getRootInterface() -> "SubscriptionObjects":
+    from modules.security.rootAccess import getRootUser
+    return SubscriptionObjects(getRootUser(), mandateId=None)
+
+
+def _getAppDatabaseConnector() -> DatabaseConnector:
+    return DatabaseConnector(
+        dbDatabase=APP_CONFIG.get("DB_DATABASE", "poweron_app"),
+        dbHost=APP_CONFIG.get("DB_HOST", "localhost"),
+        dbPort=int(APP_CONFIG.get("DB_PORT", "5432")),
+        dbUser=APP_CONFIG.get("DB_USER"),
+        dbPassword=APP_CONFIG.get("DB_PASSWORD_SECRET"),
+    )
+
+
+class SubscriptionObjects:
+    """Interface for subscription operations: CRUD, gate checks, Stripe sync.
+    All writes are ID-based. All status changes go through transitionStatus()."""
+
+    def __init__(self, currentUser: Optional[User] = None, mandateId: str = None):
+        self.currentUser = currentUser
+        self.userId = currentUser.id if currentUser else None
+        self.mandateId = mandateId
+        self.db = DatabaseConnector(
+            dbDatabase=SUBSCRIPTION_DATABASE,
+            dbHost=APP_CONFIG.get("DB_HOST", "localhost"),
+            dbPort=int(APP_CONFIG.get("DB_PORT", "5432")),
+            dbUser=APP_CONFIG.get("DB_USER"),
+            dbPassword=APP_CONFIG.get("DB_PASSWORD_SECRET"),
+        )
+
+    def setUserContext(self, currentUser: User, mandateId: str = None):
+        self.currentUser = currentUser
+        self.userId = currentUser.id if currentUser else None
+        self.mandateId = mandateId
+
+    # =========================================================================
+    # Plan catalog (in-memory)
+    # =========================================================================
+
+    def getPlan(self, planKey: str) -> Optional[SubscriptionPlan]:
+        return _getPlan(planKey)
+
+    def getSelectablePlans(self) -> List[SubscriptionPlan]:
+        return _getSelectablePlans()
+
+    # =========================================================================
+    # Read: by ID (primary access pattern)
+    # =========================================================================
+
+    def getById(self, subscriptionId: str) -> Optional[Dict[str, Any]]:
+        """Load a single subscription by its primary key."""
+        try:
+            results = self.db.getRecordset(MandateSubscription, recordFilter={"id": subscriptionId})
+            return dict(results[0]) if results else None
+        except Exception as e:
+            logger.error("getById(%s) failed: %s", subscriptionId, e)
+            return None
+
+    def getByStripeSubscriptionId(self, stripeSubId: str) -> Optional[Dict[str, Any]]:
+        """Load subscription by Stripe subscription ID — the webhook resolution path."""
+        try:
+            results = self.db.getRecordset(MandateSubscription, recordFilter={"stripeSubscriptionId": stripeSubId})
+            return dict(results[0]) if results else None
+        except Exception as e:
+            logger.error("getByStripeSubscriptionId(%s) failed: %s", stripeSubId, e)
+            return None
+
+    # =========================================================================
+    # Read: by mandate (list queries)
+    # =========================================================================
+
+    def listForMandate(self, mandateId: str, statusFilter: List[SubscriptionStatusEnum] = None) -> List[Dict[str, Any]]:
+        """Return all subscriptions for a mandate, optionally filtered by status.
+        Sorted newest-first by startedAt."""
+        try:
+            results = self.db.getRecordset(MandateSubscription, recordFilter={"mandateId": mandateId})
+            rows = [dict(r) for r in results]
+            if statusFilter:
+                filterValues = {s.value for s in statusFilter}
+                rows = [r for r in rows if r.get("status") in filterValues]
+            rows.sort(key=lambda r: r.get("startedAt", ""), reverse=True)
+            return rows
+        except Exception as e:
+            logger.error("listForMandate(%s) failed: %s", mandateId, e)
+            return []
+
+    def getOperativeForMandate(self, mandateId: str) -> Optional[Dict[str, Any]]:
+        """Return the single operative subscription (ACTIVE, TRIALING, or PAST_DUE).
+        This is a read-only query for the billing gate. Returns None if no operative sub exists."""
+        for row in self.listForMandate(mandateId):
+            if row.get("status") in {s.value for s in OPERATIVE_STATUSES}:
+                return row
+        return None
+
+    def getScheduledForMandate(self, mandateId: str) -> Optional[Dict[str, Any]]:
+        """Return a SCHEDULED subscription if one exists (next sub waiting to start)."""
+        for row in self.listForMandate(mandateId, [SubscriptionStatusEnum.SCHEDULED]):
+            return row
+        return None
+
+    # =========================================================================
+    # Read: global (SysAdmin)
+    # =========================================================================
+
+    def listAll(self, statusFilter: List[SubscriptionStatusEnum] = None) -> List[Dict[str, Any]]:
+        """Return ALL subscriptions across all mandates, newest-first. SysAdmin use only."""
+        try:
+            results = self.db.getRecordset(MandateSubscription)
+            rows = [dict(r) for r in results]
+            if statusFilter:
+                filterValues = {s.value for s in statusFilter}
+                rows = [r for r in rows if r.get("status") in filterValues]
+            rows.sort(key=lambda r: r.get("startedAt", ""), reverse=True)
+            return rows
+        except Exception as e:
+            logger.error("listAll() failed: %s", e)
+            return []
+
+    # =========================================================================
+    # Write: create
+    # =========================================================================
+
+    def createSubscription(self, sub: MandateSubscription) -> Dict[str, Any]:
+        """Persist a new MandateSubscription record."""
+        return self.db.recordCreate(MandateSubscription, sub.model_dump())
+
+    # =========================================================================
+    # Write: update fields (no status change)
+    # =========================================================================
+
+    def updateFields(self, subscriptionId: str, data: Dict[str, Any]) -> Dict[str, Any]:
+        """Update non-status fields on a subscription (e.g. recurring, Stripe IDs, periods).
+        Must NOT be used for status changes — use transitionStatus() for that."""
+        if "status" in data:
+            raise ValueError("updateFields must not change status — use transitionStatus()")
+        return self.db.recordModify(MandateSubscription, subscriptionId, data)
+
+    # =========================================================================
+    # Write: status transition (guarded)
+    # =========================================================================
+
+    def transitionStatus(
+        self,
+        subscriptionId: str,
+        expectedFromStatus: SubscriptionStatusEnum,
+        toStatus: SubscriptionStatusEnum,
+        additionalData: Dict[str, Any] = None,
+    ) -> Dict[str, Any]:
+        """Execute a guarded status transition.
+
+        1. Load the record by ID
+        2. Verify current status matches expectedFromStatus
+        3. Verify the transition is allowed by the state machine
+        4. Apply the update
+        """
+        sub = self.getById(subscriptionId)
+        if not sub:
+            raise ValueError(f"Subscription {subscriptionId} not found")
+
+        currentStatus = sub.get("status", "")
+        if currentStatus != expectedFromStatus.value:
+            raise InvalidTransitionError(subscriptionId, currentStatus, toStatus.value)
+
+        if (expectedFromStatus, toStatus) not in ALLOWED_TRANSITIONS:
+            raise InvalidTransitionError(subscriptionId, expectedFromStatus.value, toStatus.value)
+
+        updateData = {"status": toStatus.value}
+        if toStatus in TERMINAL_STATUSES and not (additionalData or {}).get("endedAt"):
+            updateData["endedAt"] = datetime.now(timezone.utc).isoformat()
+        if additionalData:
+            updateData.update(additionalData)
+
+        result = self.db.recordModify(MandateSubscription, subscriptionId, updateData)
+        logger.info("Transition %s -> %s for subscription %s", expectedFromStatus.value, toStatus.value, subscriptionId)
+        return result
+
+    def forceExpire(self, subscriptionId: str) -> Dict[str, Any]:
+        """Sysadmin force-expire: ANY non-terminal -> EXPIRED. Bypasses normal transition guards."""
+        sub = self.getById(subscriptionId)
+        if not sub:
+            raise ValueError(f"Subscription {subscriptionId} not found")
+
+        currentStatus = sub.get("status", "")
+        if currentStatus == SubscriptionStatusEnum.EXPIRED.value:
+            raise ValueError(f"Subscription {subscriptionId} is already EXPIRED")
+
+        result = self.db.recordModify(MandateSubscription, subscriptionId, {
+            "status": SubscriptionStatusEnum.EXPIRED.value,
+            "endedAt": datetime.now(timezone.utc).isoformat(),
+        })
+        logger.info("Force-expired subscription %s (was %s)", subscriptionId, currentStatus)
+        return result
+
+    # =========================================================================
+    # Gate: assertActive (read-only, for billing gate)
+    # =========================================================================
+
+    def assertActive(self, mandateId: str) -> SubscriptionStatusEnum:
+        """Return effective status for billing decisions.
+        Returns the operative subscription's status, or EXPIRED if none exists.
+        This is the ONLY read-by-mandate operation used in the hot path."""
+        sub = self.getOperativeForMandate(mandateId)
+        if sub:
+            return SubscriptionStatusEnum(sub["status"])
+        return SubscriptionStatusEnum.EXPIRED
+
+    # =========================================================================
+    # Gate: assertCapacity
+    # =========================================================================
+
+    def assertCapacity(self, mandateId: str, resourceType: str, delta: int = 1) -> bool:
+        sub = self.getOperativeForMandate(mandateId)
+        if not sub:
+            from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import SubscriptionCapacityException
+            raise SubscriptionCapacityException(
+                resourceType=resourceType, currentCount=0, maxAllowed=0,
+                message="No active subscription for this mandate.",
+            )
+
+        plan = self.getPlan(sub.get("planKey", ""))
+        if not plan:
+            return True
+
+        if resourceType == "users":
+            cap = plan.maxUsers
+            if cap is None:
+                return True
+            current = self.countActiveUsers(mandateId)
+            if current + delta > cap:
+                from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import SubscriptionCapacityException
+                raise SubscriptionCapacityException(resourceType=resourceType, currentCount=current, maxAllowed=cap)
+        elif resourceType == "featureInstances":
+            cap = plan.maxFeatureInstances
+            if cap is None:
+                return True
+            current = self.countActiveFeatureInstances(mandateId)
+            if current + delta > cap:
+                from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import SubscriptionCapacityException
+                raise SubscriptionCapacityException(resourceType=resourceType, currentCount=current, maxAllowed=cap)
+
+        return True
+
+    # =========================================================================
+    # Counting (cross-DB queries against poweron_app)
+    # =========================================================================
+
+    def countActiveUsers(self, mandateId: str) -> int:
+        try:
+            appDb = _getAppDatabaseConnector()
+            return len(appDb.getRecordset(UserMandate, recordFilter={"mandateId": mandateId}))
+        except Exception as e:
+            logger.error("countActiveUsers(%s) failed: %s", mandateId, e)
+            return 0
+
+    def countActiveFeatureInstances(self, mandateId: str) -> int:
+        try:
+            from modules.datamodels.datamodelFeatures import FeatureInstance
+            appDb = _getAppDatabaseConnector()
+            return len(appDb.getRecordset(FeatureInstance, recordFilter={"mandateId": mandateId, "enabled": True}))
+        except Exception as e:
+            logger.error("countActiveFeatureInstances(%s) failed: %s", mandateId, e)
+            return 0
+
+    # =========================================================================
+    # Stripe quantity sync
+    # =========================================================================
+
+    def syncQuantityToStripe(self, subscriptionId: str) -> None:
+        """Update Stripe subscription item quantities to match actual active counts.
+        Takes subscriptionId, not mandateId."""
+        sub = self.getById(subscriptionId)
+        if not sub or not sub.get("stripeSubscriptionId"):
+            return
+
+        mandateId = sub["mandateId"]
+        itemIdUsers = sub.get("stripeItemIdUsers")
+        itemIdInstances = sub.get("stripeItemIdInstances")
+
+        try:
+            from modules.shared.stripeClient import getStripeClient
+            stripe = getStripeClient()
+
+            activeUsers = self.countActiveUsers(mandateId)
+            activeInstances = self.countActiveFeatureInstances(mandateId)
+
+            if itemIdUsers:
+                stripe.SubscriptionItem.modify(
+                    itemIdUsers, quantity=max(activeUsers, 0), proration_behavior="create_prorations",
+                )
+            if itemIdInstances:
+                stripe.SubscriptionItem.modify(
+                    itemIdInstances, quantity=max(activeInstances, 0), proration_behavior="create_prorations",
+                )
+
+            logger.info("Stripe quantity synced for sub %s: users=%d, instances=%d", subscriptionId, activeUsers, activeInstances)
+        except Exception as e:
+            logger.error("syncQuantityToStripe(%s) failed: %s", subscriptionId, e)
--- a/modules/routes/routeAdminFeatures.py
+++ b/modules/routes/routeAdminFeatures.py
@ -518,15 +518,40 @@ def create_feature_instance(
                detail=f"Feature '{data.featureCode}' not found"
            )
        
+        # Subscription capacity check
+        mandateIdStr = str(context.mandateId)
+        try:
+            from modules.interfaces.interfaceDbSubscription import getInterface as _getSubIf
+            from modules.security.rootAccess import getRootUser
+            _subIf = _getSubIf(getRootUser(), mandateIdStr)
+            _subIf.assertCapacity(mandateIdStr, "featureInstances", delta=1)
+        except HTTPException:
+            raise
+        except Exception as capErr:
+            if "SubscriptionCapacityException" in type(capErr).__name__:
+                raise HTTPException(
+                    status_code=status.HTTP_403_FORBIDDEN,
+                    detail=str(capErr),
+                )
+
        instance = featureInterface.createFeatureInstance(
            featureCode=data.featureCode,
-            mandateId=str(context.mandateId),
+            mandateId=mandateIdStr,
            label=data.label,
            enabled=data.enabled,
            copyTemplateRoles=data.copyTemplateRoles,
            config=data.config
        )

+        # Sync Stripe quantity after successful creation
+        try:
+            from modules.interfaces.interfaceDbSubscription import getInterface as _getSubIf2
+            from modules.security.rootAccess import getRootUser as _getRU
+            _subIf2 = _getSubIf2(_getRU(), mandateIdStr)
+            _subIf2.syncQuantityToStripe(mandateIdStr)
+        except Exception:
+            pass
+
        logger.info(
            f"User {context.user.id} created feature instance '{data.label}' "
            f"for feature '{data.featureCode}' in mandate {context.mandateId}"
--- a/modules/routes/routeBilling.py
+++ b/modules/routes/routeBilling.py
@ -226,9 +226,9 @@ def _filterTransactionsByScope(transactions: list, scope: BillingDataScope) -> l
 # =============================================================================

 class CreditAddRequest(BaseModel):
-    """Request model for adding credit to an account."""
+    """Request model for adding or deducting credit from an account."""
    userId: Optional[str] = Field(None, description="Target user ID (for PREPAY_USER model)")
-    amount: float = Field(..., gt=0, description="Amount to credit in CHF")
+    amount: float = Field(..., description="Amount in CHF. Positive = credit, negative = deduction. Must not be zero.")
    description: str = Field(default="Manual credit", description="Transaction description")


@ -358,19 +358,8 @@ class UserTransactionResponse(BaseModel):

 def _getStripeClient():
    """Initialize and return configured Stripe SDK module."""
-    import stripe
-    from modules.shared.configuration import APP_CONFIG
-
-    api_version = APP_CONFIG.get("STRIPE_API_VERSION")
-    if api_version:
-        stripe.api_version = api_version
-
-    secret_key = APP_CONFIG.get("STRIPE_SECRET_KEY_SECRET") or APP_CONFIG.get("STRIPE_SECRET_KEY")
-    if not secret_key:
-        raise ValueError("STRIPE_SECRET_KEY_SECRET not configured")
-
-    stripe.api_key = secret_key
-    return stripe
+    from modules.shared.stripeClient import getStripeClient
+    return getStripeClient()


 def _creditStripeSessionIfNeeded(
@ -835,20 +824,27 @@ def addCredit(
        else:
            raise HTTPException(status_code=400, detail=f"Cannot add credit to {billingModel.value} billing model")
        
-        # Create credit transaction
+        if creditRequest.amount == 0:
+            raise HTTPException(status_code=400, detail="Amount must not be zero")
+
        from modules.datamodels.datamodelBilling import BillingTransaction

+        isDeduction = creditRequest.amount < 0
+        txType = TransactionTypeEnum.DEBIT if isDeduction else TransactionTypeEnum.CREDIT
+        absAmount = abs(creditRequest.amount)
+
        transaction = BillingTransaction(
            accountId=account["id"],
-            transactionType=TransactionTypeEnum.CREDIT,
-            amount=creditRequest.amount,
+            transactionType=txType,
+            amount=absAmount,
            description=creditRequest.description,
            referenceType=ReferenceTypeEnum.ADMIN
        )
        
        result = billingInterface.createTransaction(transaction)
        
-        logger.info(f"Added {creditRequest.amount} CHF credit to account {account['id']} in mandate {targetMandateId}")
+        action = "Deducted" if isDeduction else "Added"
+        logger.info(f"{action} {absAmount} CHF to account {account['id']} in mandate {targetMandateId}")
        
        return result
        
@ -1006,13 +1002,33 @@ async def stripeWebhook(
    
    logger.info(f"Stripe webhook received: event={event.id}, type={event.type}")

-    accepted_event_types = {"checkout.session.completed", "checkout.session.async_payment_succeeded"}
-    if event.type not in accepted_event_types:
+    # Subscription-related events
+    subscriptionEventTypes = {
+        "customer.subscription.updated",
+        "customer.subscription.deleted",
+        "invoice.paid",
+        "invoice.payment_failed",
+        "customer.subscription.trial_will_end",
+    }
+
+    # Checkout events (existing)
+    checkoutEventTypes = {"checkout.session.completed", "checkout.session.async_payment_succeeded"}
+
+    if event.type in subscriptionEventTypes:
+        _handleSubscriptionWebhook(event)
+        return {"received": True}
+
+    if event.type not in checkoutEventTypes:
        return {"received": True}

    session = event.data.object
    event_id = event.id

+    sessionMode = session.get("mode") if hasattr(session, "get") else getattr(session, "mode", None)
+    if sessionMode == "subscription":
+        _handleSubscriptionCheckoutCompleted(session, event_id)
+        return {"received": True}
+
    billingInterface = _getRootInterface()
    if billingInterface.getStripeWebhookEventByEventId(event_id):
        logger.info(f"Stripe event {event_id} already processed, skipping")
@ -1027,6 +1043,257 @@ async def stripeWebhook(
    return {"received": True}


+def _handleSubscriptionCheckoutCompleted(session, eventId: str) -> None:
+    """Handle checkout.session.completed for mode=subscription.
+    Resolves the local PENDING record by ID from webhook metadata and transitions it."""
+    from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+    from modules.datamodels.datamodelSubscription import SubscriptionStatusEnum, _getPlan
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+        _notifySubscriptionChange,
+    )
+    from modules.security.rootAccess import getRootUser
+    from datetime import datetime, timezone
+
+    metadata = {}
+    if hasattr(session, "get"):
+        metadata = session.get("metadata") or {}
+    subscriptionRecordId = metadata.get("subscriptionRecordId")
+    mandateId = metadata.get("mandateId")
+    planKey = metadata.get("planKey", "")
+
+    platformUrl = metadata.get("platformUrl", "")
+
+    if not subscriptionRecordId:
+        stripeSub = session.get("subscription")
+        if stripeSub:
+            try:
+                from modules.shared.stripeClient import getStripeClient
+                stripe = getStripeClient()
+                subObj = stripe.Subscription.retrieve(stripeSub)
+                metadata = subObj.get("metadata") or {}
+                subscriptionRecordId = metadata.get("subscriptionRecordId")
+                mandateId = metadata.get("mandateId")
+                planKey = metadata.get("planKey", "")
+                platformUrl = platformUrl or metadata.get("platformUrl", "")
+            except Exception:
+                pass
+
+    stripeSubId = session.get("subscription")
+
+    if not mandateId or not subscriptionRecordId:
+        logger.warning("Subscription checkout missing metadata: %s", metadata)
+        return
+
+    subInterface = getSubRootInterface()
+    rootUser = getRootUser()
+
+    sub = subInterface.getById(subscriptionRecordId)
+    if not sub:
+        logger.error("Subscription record %s not found for checkout webhook", subscriptionRecordId)
+        return
+    if sub.get("status") != SubscriptionStatusEnum.PENDING.value:
+        logger.warning("Subscription %s is %s, expected PENDING — skipping", subscriptionRecordId, sub.get("status"))
+        return
+
+    stripeData: Dict[str, Any] = {}
+    if stripeSubId:
+        stripeData["stripeSubscriptionId"] = stripeSubId
+        try:
+            from modules.shared.stripeClient import getStripeClient
+            stripe = getStripeClient()
+            stripeSub = stripe.Subscription.retrieve(stripeSubId, expand=["items"])
+
+            if stripeSub.get("current_period_start"):
+                stripeData["currentPeriodStart"] = datetime.fromtimestamp(
+                    stripeSub["current_period_start"], tz=timezone.utc
+                ).isoformat()
+            if stripeSub.get("current_period_end"):
+                stripeData["currentPeriodEnd"] = datetime.fromtimestamp(
+                    stripeSub["current_period_end"], tz=timezone.utc
+                ).isoformat()
+
+            from modules.serviceCenter.services.serviceSubscription.stripeBootstrap import getStripePricesForPlan
+            priceMapping = getStripePricesForPlan(planKey)
+            for item in stripeSub.get("items", {}).get("data", []):
+                priceId = item.get("price", {}).get("id", "")
+                if priceMapping and priceId == priceMapping.stripePriceIdUsers:
+                    stripeData["stripeItemIdUsers"] = item["id"]
+                elif priceMapping and priceId == priceMapping.stripePriceIdInstances:
+                    stripeData["stripeItemIdInstances"] = item["id"]
+        except Exception as e:
+            logger.error("Error retrieving Stripe subscription %s: %s", stripeSubId, e)
+
+    if stripeData:
+        subInterface.updateFields(subscriptionRecordId, stripeData)
+
+    operative = subInterface.getOperativeForMandate(mandateId)
+    hasActivePredecessor = operative is not None and operative["id"] != subscriptionRecordId
+
+    if hasActivePredecessor:
+        toStatus = SubscriptionStatusEnum.SCHEDULED
+        if operative.get("recurring", True):
+            operativeStripeId = operative.get("stripeSubscriptionId")
+            if operativeStripeId:
+                try:
+                    from modules.shared.stripeClient import getStripeClient
+                    stripe = getStripeClient()
+                    stripe.Subscription.modify(operativeStripeId, cancel_at_period_end=True)
+                except Exception as e:
+                    logger.error("Failed to set cancel_at_period_end on predecessor %s: %s", operativeStripeId, e)
+            subInterface.updateFields(operative["id"], {"recurring": False})
+        effectiveFrom = operative.get("currentPeriodEnd")
+        if effectiveFrom:
+            subInterface.updateFields(subscriptionRecordId, {"effectiveFrom": effectiveFrom})
+    else:
+        toStatus = SubscriptionStatusEnum.ACTIVE
+
+    try:
+        subInterface.transitionStatus(
+            subscriptionRecordId, SubscriptionStatusEnum.PENDING, toStatus,
+            {"recurring": True},
+        )
+    except Exception as e:
+        logger.error("Failed to transition subscription %s: %s", subscriptionRecordId, e)
+        return
+
+    subService = getSubscriptionService(rootUser, mandateId)
+    subService.invalidateCache(mandateId)
+
+    if toStatus == SubscriptionStatusEnum.ACTIVE:
+        plan = _getPlan(planKey)
+        updatedSub = subInterface.getById(subscriptionRecordId)
+        _notifySubscriptionChange(mandateId, "activated", plan, subscriptionRecord=updatedSub, platformUrl=platformUrl)
+
+    logger.info(
+        "Checkout completed: sub=%s -> %s, mandate=%s, plan=%s",
+        subscriptionRecordId, toStatus.value, mandateId, planKey,
+    )
+
+
+def _handleSubscriptionWebhook(event) -> None:
+    """Process Stripe subscription webhook events.
+    All record resolution is by stripeSubscriptionId — no mandate-based guessing."""
+    from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+    from modules.datamodels.datamodelSubscription import SubscriptionStatusEnum, _getPlan
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+        _notifySubscriptionChange,
+    )
+    from modules.security.rootAccess import getRootUser
+    from datetime import datetime, timezone
+
+    obj = event.data.object
+    stripeSubId = obj.get("id") if event.type.startswith("customer.subscription") else obj.get("subscription")
+    if not stripeSubId:
+        logger.warning("Subscription webhook %s has no subscription ID", event.type)
+        return
+
+    subInterface = getSubRootInterface()
+    sub = subInterface.getByStripeSubscriptionId(stripeSubId)
+    if not sub:
+        logger.warning("No local record for Stripe subscription %s (event: %s)", stripeSubId, event.type)
+        return
+
+    subId = sub["id"]
+    mandateId = sub["mandateId"]
+    currentStatus = SubscriptionStatusEnum(sub["status"])
+    rootUser = getRootUser()
+    subService = getSubscriptionService(rootUser, mandateId)
+
+    subMetadata = obj.get("metadata") or {}
+    webhookPlatformUrl = subMetadata.get("platformUrl", "")
+
+    if event.type == "customer.subscription.updated":
+        stripeStatus = obj.get("status", "")
+
+        periodData: Dict[str, Any] = {}
+        if obj.get("current_period_start"):
+            periodData["currentPeriodStart"] = datetime.fromtimestamp(
+                obj["current_period_start"], tz=timezone.utc
+            ).isoformat()
+        if obj.get("current_period_end"):
+            periodData["currentPeriodEnd"] = datetime.fromtimestamp(
+                obj["current_period_end"], tz=timezone.utc
+            ).isoformat()
+        if periodData:
+            subInterface.updateFields(subId, periodData)
+
+        if stripeStatus == "active" and currentStatus == SubscriptionStatusEnum.SCHEDULED:
+            subInterface.transitionStatus(subId, SubscriptionStatusEnum.SCHEDULED, SubscriptionStatusEnum.ACTIVE)
+            subService.invalidateCache(mandateId)
+            plan = _getPlan(sub.get("planKey", ""))
+            refreshedSub = subInterface.getById(subId)
+            _notifySubscriptionChange(mandateId, "activated", plan, subscriptionRecord=refreshedSub, platformUrl=webhookPlatformUrl)
+            logger.info("SCHEDULED -> ACTIVE for sub %s (mandate %s)", subId, mandateId)
+
+        elif stripeStatus == "active" and currentStatus == SubscriptionStatusEnum.PAST_DUE:
+            subInterface.transitionStatus(subId, SubscriptionStatusEnum.PAST_DUE, SubscriptionStatusEnum.ACTIVE)
+            subService.invalidateCache(mandateId)
+            logger.info("PAST_DUE -> ACTIVE for sub %s (mandate %s)", subId, mandateId)
+
+        elif stripeStatus == "past_due" and currentStatus == SubscriptionStatusEnum.ACTIVE:
+            subInterface.transitionStatus(subId, SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.PAST_DUE)
+            subService.invalidateCache(mandateId)
+            logger.info("ACTIVE -> PAST_DUE for sub %s (mandate %s)", subId, mandateId)
+
+        elif stripeStatus == "active" and currentStatus == SubscriptionStatusEnum.ACTIVE:
+            subService.invalidateCache(mandateId)
+            logger.info("Period renewed for sub %s (mandate %s)", subId, mandateId)
+
+    elif event.type == "customer.subscription.deleted":
+        if currentStatus not in (SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.PAST_DUE,
+                                  SubscriptionStatusEnum.SCHEDULED):
+            logger.info("Ignoring deletion for sub %s in status %s", subId, currentStatus.value)
+            return
+
+        subInterface.transitionStatus(subId, currentStatus, SubscriptionStatusEnum.EXPIRED)
+        subService.invalidateCache(mandateId)
+        logger.info("Sub %s -> EXPIRED (Stripe deleted, mandate %s)", subId, mandateId)
+
+        scheduled = subInterface.getScheduledForMandate(mandateId)
+        if scheduled:
+            try:
+                subInterface.transitionStatus(
+                    scheduled["id"], SubscriptionStatusEnum.SCHEDULED, SubscriptionStatusEnum.ACTIVE,
+                )
+                subService.invalidateCache(mandateId)
+                plan = _getPlan(scheduled.get("planKey", ""))
+                refreshedScheduled = subInterface.getById(scheduled["id"])
+                _notifySubscriptionChange(mandateId, "activated", plan, subscriptionRecord=refreshedScheduled, platformUrl=webhookPlatformUrl)
+                logger.info("Promoted SCHEDULED sub %s -> ACTIVE (mandate %s)", scheduled["id"], mandateId)
+            except Exception as e:
+                logger.error("Failed to promote SCHEDULED sub %s: %s", scheduled["id"], e)
+
+    elif event.type == "invoice.payment_failed":
+        if currentStatus == SubscriptionStatusEnum.ACTIVE:
+            subInterface.transitionStatus(subId, SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.PAST_DUE)
+            subService.invalidateCache(mandateId)
+            plan = _getPlan(sub.get("planKey", ""))
+            _notifySubscriptionChange(mandateId, "payment_failed", plan, subscriptionRecord=sub, platformUrl=webhookPlatformUrl)
+            logger.info("Payment failed for sub %s (mandate %s)", subId, mandateId)
+
+    elif event.type == "customer.subscription.trial_will_end":
+        logger.info("Trial ending soon for sub %s (mandate %s)", subId, mandateId)
+        try:
+            from modules.shared.notifyMandateAdmins import notifyMandateAdmins
+            notifyMandateAdmins(
+                mandateId,
+                "[PowerOn] Testphase endet bald",
+                "Testphase endet bald",
+                [
+                    "Die kostenlose Testphase für Ihren Mandanten endet in Kürze.",
+                    "Bitte wählen Sie einen Plan unter Billing-Verwaltung › Abonnement.",
+                ],
+            )
+        except Exception as e:
+            logger.error("Failed to notify about trial ending: %s", e)
+
+    elif event.type == "invoice.paid":
+        logger.info("Invoice paid for sub %s (mandate %s)", subId, mandateId)
+    return None
+
+
@router.get("/admin/accounts/{targetMandateId}", response_model=List[AccountSummary])
@limiter.limit("30/minute")
 def getAccounts(
--- a/modules/routes/routeSubscription.py
+++ b/modules/routes/routeSubscription.py
@ -0,0 +1,364 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Subscription routes — ID-based, state-machine-driven.
+
+Endpoints:
+- GET  /api/subscription/plans           — list selectable plans
+- GET  /api/subscription/status          — operative + scheduled subscription for current mandate
+- POST /api/subscription/activate        — start checkout for a plan
+- POST /api/subscription/cancel          — cancel a specific subscription (by ID)
+- POST /api/subscription/reactivate      — reactivate a cancelled subscription (by ID)
+- POST /api/subscription/force-cancel    — sysadmin immediate cancel (by ID)
+"""
+
+from fastapi import APIRouter, HTTPException, Depends, Request
+from fastapi import status
+from typing import Dict, Any, List, Optional
+import logging
+from pydantic import BaseModel, Field
+
+from modules.auth import limiter, getRequestContext, RequestContext
+
+logger = logging.getLogger(__name__)
+
+
+def _resolveMandateId(context: RequestContext) -> str:
+    if context.mandateId:
+        return str(context.mandateId)
+    return ""
+
+
+def _assertMandateAdmin(context: RequestContext, mandateId: str) -> None:
+    if context.hasSysAdminRole:
+        return
+    try:
+        from modules.interfaces.interfaceDbApp import getRootInterface
+        rootInterface = getRootInterface()
+        userMandates = rootInterface.getUserMandates(str(context.user.id))
+        for um in userMandates:
+            if str(getattr(um, "mandateId", None)) != str(mandateId):
+                continue
+            if not getattr(um, "enabled", True):
+                continue
+            umId = str(getattr(um, "id", ""))
+            roleIds = rootInterface.getRoleIdsForUserMandate(umId)
+            for roleId in roleIds:
+                role = rootInterface.getRole(roleId)
+                if role and role.roleLabel == "admin" and not role.featureInstanceId:
+                    return
+    except Exception:
+        pass
+    raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Mandate admin role required")
+
+
+# =============================================================================
+# Request / Response models
+# =============================================================================
+
+class ActivatePlanRequest(BaseModel):
+    planKey: str = Field(..., description="Key of the plan to activate")
+    returnUrl: str = Field(..., description="Frontend URL to redirect back to after Stripe Checkout")
+
+class CancelRequest(BaseModel):
+    subscriptionId: str = Field(..., description="ID of the subscription to cancel")
+
+class ReactivateRequest(BaseModel):
+    subscriptionId: str = Field(..., description="ID of the subscription to reactivate")
+
+class ForceCancelRequest(BaseModel):
+    subscriptionId: str = Field(..., description="ID of the subscription to force-cancel")
+
+class VerifyCheckoutRequest(BaseModel):
+    sessionId: str = Field(..., description="Stripe Checkout Session ID to verify")
+
+class SubscriptionStatusResponse(BaseModel):
+    active: bool
+    subscription: Optional[Dict[str, Any]] = None
+    plan: Optional[Dict[str, Any]] = None
+    scheduled: Optional[Dict[str, Any]] = None
+
+
+# =============================================================================
+# Router
+# =============================================================================
+
+router = APIRouter(
+    prefix="/api/subscription",
+    tags=["Subscription"],
+    responses={404: {"description": "Not found"}},
+)
+
+
+# =============================================================================
+# Endpoints
+# =============================================================================
+
+@router.get("/plans", response_model=List[Dict[str, Any]])
+@limiter.limit("30/minute")
+def getPlans(request: Request, context: RequestContext = Depends(getRequestContext)):
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    try:
+        mandateId = _resolveMandateId(context)
+        subService = getSubscriptionService(context.user, mandateId)
+        plans = subService.getSelectablePlans()
+        return [p.model_dump() for p in plans]
+    except Exception as e:
+        logger.error("Error fetching plans: %s", e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/status", response_model=SubscriptionStatusResponse)
+@limiter.limit("60/minute")
+def getStatus(request: Request, context: RequestContext = Depends(getRequestContext)):
+    """Return the operative subscription and any scheduled successor for the current mandate."""
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    mandateId = _resolveMandateId(context)
+    if not mandateId:
+        return SubscriptionStatusResponse(active=False)
+    _assertMandateAdmin(context, mandateId)
+
+    try:
+        subService = getSubscriptionService(context.user, mandateId)
+        operative = subService.getOperativeSubscription(mandateId)
+        scheduled = subService.getScheduledSubscription(mandateId)
+
+        if not operative:
+            from modules.datamodels.datamodelSubscription import SubscriptionStatusEnum
+            pending = subService.listSubscriptions(mandateId, [SubscriptionStatusEnum.PENDING])
+            if pending:
+                sub = pending[0]
+                plan = subService.getPlan(sub.get("planKey", ""))
+                return SubscriptionStatusResponse(
+                    active=False,
+                    subscription=sub,
+                    plan=plan.model_dump() if plan else None,
+                    scheduled=scheduled,
+                )
+            return SubscriptionStatusResponse(active=False, scheduled=scheduled)
+
+        plan = subService.getPlan(operative.get("planKey", ""))
+        return SubscriptionStatusResponse(
+            active=True,
+            subscription=operative,
+            plan=plan.model_dump() if plan else None,
+            scheduled=scheduled,
+        )
+    except Exception as e:
+        logger.error("Error fetching status: %s", e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/activate", response_model=Dict[str, Any])
+@limiter.limit("10/minute")
+def activatePlan(
+    request: Request,
+    data: ActivatePlanRequest,
+    context: RequestContext = Depends(getRequestContext),
+):
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    mandateId = _resolveMandateId(context)
+    if not mandateId:
+        raise HTTPException(status_code=400, detail="X-Mandate-Id header required")
+    _assertMandateAdmin(context, mandateId)
+
+    try:
+        subService = getSubscriptionService(context.user, mandateId)
+        return subService.activatePlan(mandateId, data.planKey, returnUrl=data.returnUrl)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error("Error activating plan %s: %s", data.planKey, e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/cancel", response_model=Dict[str, Any])
+@limiter.limit("5/minute")
+def cancelSubscription(
+    request: Request,
+    data: CancelRequest,
+    context: RequestContext = Depends(getRequestContext),
+):
+    """Cancel a specific subscription by its ID."""
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    mandateId = _resolveMandateId(context)
+    if not mandateId:
+        raise HTTPException(status_code=400, detail="X-Mandate-Id header required")
+    _assertMandateAdmin(context, mandateId)
+
+    try:
+        subService = getSubscriptionService(context.user, mandateId)
+        return subService.cancelSubscription(data.subscriptionId)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error("Error cancelling subscription %s: %s", data.subscriptionId, e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/reactivate", response_model=Dict[str, Any])
+@limiter.limit("5/minute")
+def reactivateSubscription(
+    request: Request,
+    data: ReactivateRequest,
+    context: RequestContext = Depends(getRequestContext),
+):
+    """Reactivate a cancelled (non-recurring) subscription before its period ends."""
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    mandateId = _resolveMandateId(context)
+    if not mandateId:
+        raise HTTPException(status_code=400, detail="X-Mandate-Id header required")
+    _assertMandateAdmin(context, mandateId)
+
+    try:
+        subService = getSubscriptionService(context.user, mandateId)
+        return subService.reactivateSubscription(data.subscriptionId)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error("Error reactivating subscription %s: %s", data.subscriptionId, e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/force-cancel", response_model=Dict[str, Any])
+@limiter.limit("5/minute")
+def forceCancel(
+    request: Request,
+    data: ForceCancelRequest,
+    context: RequestContext = Depends(getRequestContext),
+):
+    """Sysadmin: immediately expire any non-terminal subscription."""
+    if not context.hasSysAdminRole:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Sysadmin role required")
+
+    from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+        getService as getSubscriptionService,
+    )
+    from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+    sub = getSubRootInterface().getById(data.subscriptionId)
+    if not sub:
+        raise HTTPException(status_code=404, detail="Subscription not found")
+    mandateId = sub["mandateId"]
+
+    try:
+        subService = getSubscriptionService(context.user, mandateId)
+        return subService.forceCancel(data.subscriptionId)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        logger.error("Error force-cancelling subscription %s: %s", data.subscriptionId, e)
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.post("/checkout/verify", response_model=Dict[str, Any])
+@limiter.limit("20/minute")
+def verifyCheckout(
+    request: Request,
+    data: VerifyCheckoutRequest,
+    context: RequestContext = Depends(getRequestContext),
+):
+    """Verify a Stripe Checkout Session and activate the subscription if paid.
+
+    This is the synchronous counterpart to the checkout.session.completed webhook.
+    It's called by the frontend immediately after returning from Stripe to handle
+    environments where webhooks may be delayed or unavailable (e.g. localhost dev).
+    The logic is idempotent — if the webhook already processed the session, this is a no-op.
+    """
+    mandateId = _resolveMandateId(context)
+    if not mandateId:
+        raise HTTPException(status_code=400, detail="X-Mandate-Id header required")
+    _assertMandateAdmin(context, mandateId)
+
+    try:
+        from modules.shared.stripeClient import getStripeClient
+        stripe = getStripeClient()
+        session = stripe.checkout.Session.retrieve(data.sessionId)
+    except Exception as e:
+        logger.error("Failed to retrieve checkout session %s: %s", data.sessionId, e)
+        raise HTTPException(status_code=400, detail="Invalid session ID")
+
+    if session.get("status") != "complete" or session.get("payment_status") != "paid":
+        return {"status": "pending", "message": "Checkout not yet completed"}
+
+    if session.get("mode") != "subscription":
+        raise HTTPException(status_code=400, detail="Not a subscription checkout session")
+
+    from modules.routes.routeBilling import _handleSubscriptionCheckoutCompleted
+    _handleSubscriptionCheckoutCompleted(session, f"verify-{data.sessionId}")
+
+    return {"status": "activated", "message": "Subscription activated"}
+
+
+# =============================================================================
+# SysAdmin: global subscription overview
+# =============================================================================
+
+@router.get("/admin/all", response_model=List[Dict[str, Any]])
+@limiter.limit("30/minute")
+def getAllSubscriptions(
+    request: Request,
+    context: RequestContext = Depends(getRequestContext),
+):
+    """SysAdmin: list ALL subscriptions across all mandates with enriched metadata."""
+    if not context.hasSysAdminRole:
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Sysadmin role required")
+
+    from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+    from modules.datamodels.datamodelSubscription import BUILTIN_PLANS, OPERATIVE_STATUSES
+
+    subInterface = getSubRootInterface()
+    allSubs = subInterface.listAll()
+
+    mandateNames: Dict[str, str] = {}
+    try:
+        from modules.datamodels.datamodelUam import Mandate
+        from modules.security.rootAccess import getRootDbAppConnector
+        appDb = getRootDbAppConnector()
+        for row in appDb.getRecordset(Mandate):
+            r = dict(row)
+            mid = r.get("id", "")
+            mandateNames[mid] = r.get("label") or r.get("name") or mid[:8]
+    except Exception as e:
+        logger.warning("Could not bulk-resolve mandate names: %s", e)
+
+    operativeValues = {s.value for s in OPERATIVE_STATUSES}
+
+    enriched = []
+    for sub in allSubs:
+        mid = sub.get("mandateId", "")
+        planKey = sub.get("planKey", "")
+        plan = BUILTIN_PLANS.get(planKey)
+
+        sub["mandateName"] = mandateNames.get(mid, mid[:8])
+        sub["planTitle"] = (plan.title.get("de") or plan.title.get("en") or planKey) if plan else planKey
+
+        if sub.get("status") in operativeValues:
+            userPrice = sub.get("snapshotPricePerUserCHF", 0) or 0
+            instPrice = sub.get("snapshotPricePerInstanceCHF", 0) or 0
+            try:
+                userCount = subInterface.countActiveUsers(mid)
+                instanceCount = subInterface.countActiveFeatureInstances(mid)
+            except Exception:
+                userCount = 0
+                instanceCount = 0
+            sub["monthlyRevenueCHF"] = round(userPrice * userCount + instPrice * instanceCount, 2)
+            sub["activeUsers"] = userCount
+            sub["activeInstances"] = instanceCount
+        else:
+            sub["monthlyRevenueCHF"] = 0
+            sub["activeUsers"] = 0
+            sub["activeInstances"] = 0
+
+        enriched.append(sub)
+
+    return enriched
--- a/modules/serviceCenter/registry.py
+++ b/modules/serviceCenter/registry.py
@ -45,10 +45,17 @@ IMPORTABLE_SERVICES: Dict[str, Dict[str, Any]] = {
    "billing": {
        "module": "modules.serviceCenter.services.serviceBilling.mainServiceBilling",
        "class": "BillingService",
-        "dependencies": [],
+        "dependencies": ["subscription"],
        "objectKey": "service.billing",
        "label": {"en": "Billing", "de": "Abrechnung", "fr": "Facturation"},
    },
+    "subscription": {
+        "module": "modules.serviceCenter.services.serviceSubscription.mainServiceSubscription",
+        "class": "SubscriptionService",
+        "dependencies": [],
+        "objectKey": "service.subscription",
+        "label": {"en": "Subscription", "de": "Abonnement", "fr": "Abonnement"},
+    },
    "sharepoint": {
        "module": "modules.serviceCenter.services.serviceSharepoint.mainServiceSharepoint",
        "class": "SharepointService",
--- a/modules/serviceCenter/services/serviceAgent/agentLoop.py
+++ b/modules/serviceCenter/services/serviceAgent/agentLoop.py
@ -25,6 +25,9 @@ from modules.shared.jsonUtils import closeJsonStructures
 from modules.serviceCenter.services.serviceBilling.mainServiceBilling import (
    InsufficientBalanceException,
 )
+from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+    SubscriptionInactiveException,
+)

 logger = logging.getLogger(__name__)

@ -191,6 +194,18 @@ async def runAgentLoop(
            else:
                aiResponse = await aiCallFn(aiRequest)

+        except SubscriptionInactiveException as e:
+            logger.warning(
+                f"Subscription inactive in round {state.currentRound} (mandate={mandateId}): {e.message}"
+            )
+            state.status = AgentStatusEnum.ERROR
+            state.abortReason = e.message
+            yield AgentEvent(
+                type=AgentEventTypeEnum.ERROR,
+                content=e.message,
+                data=e.toClientDict(),
+            )
+            break
        except InsufficientBalanceException as e:
            logger.warning(
                f"Insufficient balance in round {state.currentRound} (mandate={mandateId}): {e.message}"
--- a/modules/serviceCenter/services/serviceAi/mainServiceAi.py
+++ b/modules/serviceCenter/services/serviceAi/mainServiceAi.py
@ -27,6 +27,10 @@ from modules.serviceCenter.services.serviceBilling.mainServiceBilling import (
    ProviderNotAllowedException,
    BillingContextError
 )
+from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+    SubscriptionInactiveException,
+    SUBSCRIPTION_REASONS,
+)

 logger = logging.getLogger(__name__)

@ -590,11 +594,25 @@ detectedIntent-Werte:
            balanceCheck = billingService.checkBalance(estimatedCost)
            
            if not balanceCheck.allowed:
+                reason = balanceCheck.reason or ""
+
+                if reason in SUBSCRIPTION_REASONS:
+                    from modules.datamodels.datamodelSubscription import SubscriptionStatusEnum
+                    statusMap = {
+                        "SUBSCRIPTION_PAYMENT_REQUIRED": SubscriptionStatusEnum.PAST_DUE,
+                        "SUBSCRIPTION_EXPIRED": SubscriptionStatusEnum.EXPIRED,
+                        "SUBSCRIPTION_INACTIVE": SubscriptionStatusEnum.EXPIRED,
+                    }
+                    raise SubscriptionInactiveException(
+                        status=statusMap.get(reason, SubscriptionStatusEnum.EXPIRED),
+                        mandateId=str(mandateId),
+                    )
+
                balance_str = f"{(balanceCheck.currentBalance or 0):.2f}"
                logger.warning(
                    f"Billing check failed for user {user.id}: "
                    f"Balance {balance_str} CHF, "
-                    f"Reason: {balanceCheck.reason}"
+                    f"Reason: {reason}"
                )
                if balanceCheck.billingModel == BillingModelEnum.PREPAY_MANDATE:
                    ulabel = (getattr(user, "email", None) or getattr(user, "username", None) or str(user.id))
@ -651,6 +669,8 @@ detectedIntent-Werte:
            
            logger.debug(f"Provider check passed: {len(rbacAllowedProviders)} providers allowed")
            
+        except SubscriptionInactiveException:
+            raise
        except InsufficientBalanceException:
            raise
        except ProviderNotAllowedException:
@ -658,7 +678,6 @@ detectedIntent-Werte:
        except BillingContextError:
            raise
        except Exception as e:
-            # FAIL-SAFE: Don't silently swallow errors - log at ERROR level
            logger.error(f"BILLING FAIL-SAFE: Billing check failed with unexpected error: {e}")
            raise BillingContextError(f"Billing check failed: {e}")

--- a/modules/serviceCenter/services/serviceBilling/billingExhaustedNotify.py
+++ b/modules/serviceCenter/services/serviceBilling/billingExhaustedNotify.py
@ -1,23 +1,17 @@
 # Copyright (c) 2025 Patrick Motsch
 # All rights reserved.
 """
-When the shared mandate pool (PREPAY_MANDATE) is exhausted, notify billing contacts.
+When the shared mandate pool (PREPAY_MANDATE) is exhausted, notify mandate admins.

-Recipients: BillingSettings.notifyEmails for the mandate (configure as mandate owner / finance).
+Uses the central notifyMandateAdmins() function for recipient resolution and delivery.
 Emails are throttled per mandate to avoid spam (one notification per cooldown window).
 """

 from __future__ import annotations

-import html
 import logging
 import time
-from typing import Any, Dict, List, Optional
-
-from modules.datamodels.datamodelMessaging import MessagingChannel
-from modules.interfaces.interfaceDbBilling import getInterface as getBillingInterface
-from modules.interfaces.interfaceMessaging import getInterface as getMessagingInterface
-from modules.security.rootAccess import getRootUser
+from typing import Dict

 logger = logging.getLogger(__name__)

@ -26,29 +20,6 @@ _poolExhaustedEmailLastSent: Dict[str, float] = {}
 _DEFAULT_COOLDOWN_SEC = 3600


-def _normalizeNotifyEmails(raw: Any) -> List[str]:
-    if raw is None:
-        return []
-    if isinstance(raw, list):
-        return [str(e).strip() for e in raw if str(e).strip()]
-    if isinstance(raw, str):
-        s = raw.strip()
-        if not s:
-            return []
-        # JSON array string
-        if s.startswith("["):
-            try:
-                import json
-
-                parsed = json.loads(s)
-                if isinstance(parsed, list):
-                    return [str(e).strip() for e in parsed if str(e).strip()]
-            except Exception:
-                pass
-        return [s]
-    return []
-
-
 def maybeEmailMandatePoolExhausted(
    mandateId: str,
    triggeringUserId: str,
@ -58,7 +29,7 @@ def maybeEmailMandatePoolExhausted(
    cooldownSec: float = _DEFAULT_COOLDOWN_SEC,
 ) -> None:
    """
-    Send one email per mandate per cooldown to BillingSettings.notifyEmails.
+    Send one notification per mandate per cooldown window when the pool is exhausted.

    Args:
        mandateId: Mandate whose pool is empty.
@ -82,59 +53,22 @@ def maybeEmailMandatePoolExhausted(
        return

    try:
-        billing = getBillingInterface(getRootUser(), mandateId)
-        settings = billing.getSettings(mandateId) or {}
-        recipients = _normalizeNotifyEmails(settings.get("notifyEmails"))
-        if not recipients:
-            logger.warning(
-                "PREPAY_MANDATE pool exhausted for mandate %s but notifyEmails is empty — "
-                "configure BillingSettings.notifyEmails for owner alerts",
-                mandateId,
-            )
-            return
+        from modules.shared.notifyMandateAdmins import notifyMandateAdmins

-        subject = f"[PowerOn] Mandanten-Budget aufgebraucht (Mandant {mandateId[:8]}…)"
-        body = (
-            f"Das gemeinsame Guthaben (PREPAY_MANDATE) für diesen Mandanten ist nicht mehr ausreichend.\n\n"
-            f"Mandanten-ID: {mandateId}\n"
-            f"Aktuelles Guthaben (Pool): CHF {currentBalance:.2f}\n"
-            f"Benötigt (mind.): CHF {requiredAmount:.2f}\n\n"
-            f"Auslösende/r Benutzer/in: {triggeringUserLabel} (ID: {triggeringUserId})\n\n"
-            f"Bitte laden Sie das Mandats-Guthaben in der Billing-Verwaltung auf, "
-            f"damit Benutzer wieder AI-Funktionen nutzen können.\n"
+        sent = notifyMandateAdmins(
+            mandateId,
+            "[PowerOn] Mandanten-Budget aufgebraucht",
+            "Budget aufgebraucht",
+            [
+                "Das gemeinsame Guthaben (Prepaid-Pool) für diesen Mandanten ist nicht mehr ausreichend.",
+                f"Aktuelles Guthaben: CHF {currentBalance:.2f}\n"
+                f"Benötigt (mindestens): CHF {requiredAmount:.2f}",
+                f"Ausgelöst durch: {triggeringUserLabel}",
+                "Bitte laden Sie das Mandats-Guthaben in der Billing-Verwaltung auf, "
+                "damit Benutzer wieder AI-Funktionen nutzen können.",
+            ],
        )
-        escaped = html.escape(body)
-        # Cannot use '\\n' inside f-string {…} expression (SyntaxError); build replacement outside.
-        brWithNl = "<br>" + "\n"
-        htmlMessage = f"""<!DOCTYPE html>
-<html><head><meta charset="utf-8"></head>
-<body style="font-family: Arial, sans-serif; line-height: 1.6;">
-{escaped.replace(chr(10), brWithNl)}
-</body></html>"""
-
-        messaging = getMessagingInterface()
-        any_ok = False
-        for to in recipients:
-            try:
-                ok = messaging.send(
-                    channel=MessagingChannel.EMAIL,
-                    recipient=to,
-                    subject=subject,
-                    message=htmlMessage,
-                )
-                if ok:
-                    any_ok = True
-                else:
-                    logger.warning("Pool exhausted email failed for %s", to)
-            except Exception as send_err:
-                logger.error("Error sending pool exhausted email to %s: %s", to, send_err)
-
-        if any_ok:
+        if sent > 0:
            _poolExhaustedEmailLastSent[mandateId] = now
-            logger.info(
-                "Sent mandate pool exhausted notification for mandate %s to %s recipient(s)",
-                mandateId,
-                len(recipients),
-            )
    except Exception as e:
        logger.error("maybeEmailMandatePoolExhausted failed: %s", e, exc_info=True)
--- a/modules/serviceCenter/services/serviceBilling/mainServiceBilling.py
+++ b/modules/serviceCenter/services/serviceBilling/mainServiceBilling.py
@ -161,18 +161,53 @@ class BillingService:
        """
        Check if the current user/mandate has sufficient balance.

+        Gate order:
+        1. Subscription active? (fast, cached) — blocks AI if not
+        2. Budget sufficient? (existing prepaid logic)
+        
        Args:
            estimatedCost: Estimated cost of the operation (with markup applied)
            
        Returns:
            BillingCheckResult indicating if operation is allowed
        """
+        subResult = self._checkSubscription()
+        if subResult is not None:
+            return subResult
+
        return self._billingInterface.checkBalance(
            self.mandateId,
            self.currentUser.id,
            estimatedCost
        )

+    def _checkSubscription(self) -> Optional[BillingCheckResult]:
+        """Return a failing BillingCheckResult if subscription is not active, else None."""
+        try:
+            from modules.datamodels.datamodelSubscription import SubscriptionStatusEnum
+            from modules.serviceCenter.services.serviceSubscription.mainServiceSubscription import (
+                getService as getSubscriptionService,
+                _subscriptionReasonForStatus,
+                _subscriptionUserActionForStatus,
+            )
+
+            subService = getSubscriptionService(self.currentUser, self.mandateId)
+            status = subService.assertActive(self.mandateId)
+
+            if status in (SubscriptionStatusEnum.ACTIVE, SubscriptionStatusEnum.TRIALING, SubscriptionStatusEnum.PAST_DUE):
+                return None
+
+            return BillingCheckResult(
+                allowed=False,
+                reason=_subscriptionReasonForStatus(status),
+                upgradeRequired=True,
+                subscriptionUiPath="/admin/billing?tab=subscription",
+                userAction=_subscriptionUserActionForStatus(status),
+            )
+        except Exception as e:
+            logger.warning(f"Subscription check failed (allowing): {e}")
+            return None
+    
    def hasBalance(self, estimatedCost: float = 0.0) -> bool:
        """
        Quick check if balance is sufficient.
--- a/modules/serviceCenter/services/serviceBilling/stripeCheckout.py
+++ b/modules/serviceCenter/services/serviceBilling/stripeCheckout.py
@ -82,17 +82,8 @@ def create_checkout_session(
            f"Invalid amount {amount_chf} CHF. Allowed: {ALLOWED_AMOUNTS_CHF}"
        )
    
-    # Pin API version from config (match Stripe Dashboard)
-    api_version = APP_CONFIG.get("STRIPE_API_VERSION")
-    if api_version:
-        stripe.api_version = api_version
-    
-    # Get secrets
-    secret_key = APP_CONFIG.get("STRIPE_SECRET_KEY_SECRET") or APP_CONFIG.get("STRIPE_SECRET_KEY")
-    if not secret_key:
-        raise ValueError("STRIPE_SECRET_KEY_SECRET not configured")
-    
-    stripe.api_key = secret_key
+    from modules.shared.stripeClient import getStripeClient
+    stripe = getStripeClient()
    
    base_return_url = _normalizeReturnUrl(return_url)
    query_separator = "&" if "?" in base_return_url else "?"
--- a/modules/serviceCenter/services/serviceSubscription/init.py
+++ b/modules/serviceCenter/services/serviceSubscription/init.py
--- a/modules/serviceCenter/services/serviceSubscription/mainServiceSubscription.py
+++ b/modules/serviceCenter/services/serviceSubscription/mainServiceSubscription.py
@ -0,0 +1,710 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Subscription Service — state-machine-based lifecycle management.
+
+Every mutation takes an explicit subscriptionId. No status-scan guessing.
+See wiki/concepts/Subscription-State-Machine.md for the full state machine.
+"""
+
+import logging
+import time
+from typing import Dict, Any, List, Optional
+from datetime import datetime, timezone, timedelta
+
+from modules.datamodels.datamodelUam import User
+from modules.datamodels.datamodelSubscription import (
+    SubscriptionPlan,
+    MandateSubscription,
+    SubscriptionStatusEnum,
+    BillingPeriodEnum,
+    OPERATIVE_STATUSES,
+    _getPlan,
+    _getSelectablePlans,
+)
+from modules.interfaces.interfaceDbSubscription import (
+    getInterface as getSubscriptionInterface,
+    InvalidTransitionError,
+)
+
+logger = logging.getLogger(__name__)
+
+SUBSCRIPTION_CACHE_TTL_SECONDS = 60
+_STALE_PENDING_SECONDS = 30 * 60
+
+_subscriptionServices: Dict[str, "SubscriptionService"] = {}
+_statusCache: Dict[str, tuple] = {}
+
+
+def getService(currentUser: User, mandateId: str) -> "SubscriptionService":
+    cacheKey = f"{currentUser.id}_{mandateId}"
+    if cacheKey not in _subscriptionServices:
+        _subscriptionServices[cacheKey] = SubscriptionService(currentUser, mandateId)
+    else:
+        _subscriptionServices[cacheKey].setContext(currentUser, mandateId)
+    return _subscriptionServices[cacheKey]
+
+
+class SubscriptionService:
+    """State-machine-based subscription service.
+    All mutations use explicit subscriptionId. No scan-based writes."""
+
+    def __init__(self, contextOrUser, mandateId=None, get_service=None):
+        if mandateId is not None and callable(mandateId):
+            ctx = contextOrUser
+            self.currentUser = ctx.user
+            self.mandateId = ctx.mandate_id or ""
+        elif get_service is not None and hasattr(contextOrUser, "user"):
+            ctx = contextOrUser
+            self.currentUser = ctx.user
+            self.mandateId = ctx.mandate_id or ""
+        else:
+            self.currentUser = contextOrUser
+            self.mandateId = mandateId or ""
+        self._interface = getSubscriptionInterface(self.currentUser, self.mandateId)
+
+    def setContext(self, currentUser: User, mandateId: str):
+        self.currentUser = currentUser
+        self.mandateId = mandateId
+        self._interface = getSubscriptionInterface(currentUser, mandateId)
+
+    # =========================================================================
+    # Billing gate (cached, read-only)
+    # =========================================================================
+
+    def assertActive(self, mandateId: str = None) -> SubscriptionStatusEnum:
+        """Return subscription status for billing decisions. Uses TTL cache.
+        This is the ONLY method that works by mandateId (read-only)."""
+        mid = mandateId or self.mandateId
+        now = time.monotonic()
+
+        cached = _statusCache.get(mid)
+        if cached and cached[1] > now:
+            return cached[0]
+
+        status = self._interface.assertActive(mid)
+        _statusCache[mid] = (status, now + SUBSCRIPTION_CACHE_TTL_SECONDS)
+        return status
+
+    def invalidateCache(self, mandateId: str = None):
+        mid = mandateId or self.mandateId
+        _statusCache.pop(mid, None)
+
+    # =========================================================================
+    # Capacity (delegation)
+    # =========================================================================
+
+    def assertCapacity(self, mandateId: str, resourceType: str, delta: int = 1) -> bool:
+        return self._interface.assertCapacity(mandateId or self.mandateId, resourceType, delta)
+
+    # =========================================================================
+    # Read operations
+    # =========================================================================
+
+    def getById(self, subscriptionId: str) -> Optional[Dict[str, Any]]:
+        return self._interface.getById(subscriptionId)
+
+    def getOperativeSubscription(self, mandateId: str = None) -> Optional[Dict[str, Any]]:
+        return self._interface.getOperativeForMandate(mandateId or self.mandateId)
+
+    def getScheduledSubscription(self, mandateId: str = None) -> Optional[Dict[str, Any]]:
+        return self._interface.getScheduledForMandate(mandateId or self.mandateId)
+
+    def listSubscriptions(self, mandateId: str = None, statusFilter=None) -> List[Dict[str, Any]]:
+        return self._interface.listForMandate(mandateId or self.mandateId, statusFilter)
+
+    def getSelectablePlans(self) -> List[SubscriptionPlan]:
+        return _getSelectablePlans()
+
+    def getPlan(self, planKey: str) -> Optional[SubscriptionPlan]:
+        return _getPlan(planKey)
+
+    # =========================================================================
+    # T1/T2: Plan activation (creates PENDING, returns checkout URL)
+    # =========================================================================
+
+    def activatePlan(self, mandateId: str, planKey: str, returnUrl: str) -> Dict[str, Any]:
+        """Create a new subscription as PENDING and start the checkout flow.
+
+        - Free/trial plans: immediately ACTIVE/TRIALING (no checkout).
+        - Paid plans with active predecessor: PENDING -> checkout -> SCHEDULED on confirmation.
+        - Paid plans without predecessor: PENDING -> checkout -> ACTIVE on confirmation.
+
+        Cleans up any existing PENDING/SCHEDULED for this mandate first (by ID)."""
+        mid = mandateId or self.mandateId
+        plan = _getPlan(planKey)
+        if not plan:
+            raise ValueError(f"Unknown plan: {planKey}")
+
+        isPaid = plan.billingPeriod != BillingPeriodEnum.NONE and not plan.trialDays
+        currentOperative = self._interface.getOperativeForMandate(mid)
+
+        self._cleanupPreparatorySubscriptions(mid)
+
+        now = datetime.now(timezone.utc)
+        if plan.trialDays:
+            initialStatus = SubscriptionStatusEnum.TRIALING
+        elif isPaid:
+            initialStatus = SubscriptionStatusEnum.PENDING
+        else:
+            initialStatus = SubscriptionStatusEnum.ACTIVE
+
+        sub = MandateSubscription(
+            mandateId=mid,
+            planKey=planKey,
+            status=initialStatus,
+            recurring=plan.autoRenew and not plan.trialDays,
+            startedAt=now,
+            currentPeriodStart=now,
+            snapshotPricePerUserCHF=plan.pricePerUserCHF,
+            snapshotPricePerInstanceCHF=plan.pricePerFeatureInstanceCHF,
+        )
+
+        if plan.trialDays:
+            sub.trialEndsAt = now + timedelta(days=plan.trialDays)
+
+        if plan.billingPeriod == BillingPeriodEnum.MONTHLY:
+            sub.currentPeriodEnd = now + timedelta(days=30)
+        elif plan.billingPeriod == BillingPeriodEnum.YEARLY:
+            sub.currentPeriodEnd = now + timedelta(days=365)
+
+        created = self._interface.createSubscription(sub)
+
+        from urllib.parse import urlparse
+        parsed = urlparse(returnUrl) if returnUrl else None
+        pUrl = f"{parsed.scheme}://{parsed.netloc}" if parsed and parsed.scheme else ""
+
+        if isPaid:
+            try:
+                checkoutUrl = self._createCheckoutSession(mid, plan, created, currentOperative, returnUrl)
+                created["redirectUrl"] = checkoutUrl
+            except Exception as e:
+                self._interface.forceExpire(created["id"])
+                self.invalidateCache(mid)
+                raise ValueError(f"Subscription konnte nicht erstellt werden: {e}") from e
+        else:
+            if currentOperative:
+                self._expireOperative(currentOperative["id"], mid)
+            _notifySubscriptionChange(mid, "activated", plan, subscriptionRecord=created, platformUrl=pUrl)
+
+        self.invalidateCache(mid)
+        return created
+
+    def _cleanupPreparatorySubscriptions(self, mandateId: str) -> None:
+        """Expire any existing PENDING or SCHEDULED subscriptions for this mandate (by ID)."""
+        preparatory = self._interface.listForMandate(
+            mandateId, [SubscriptionStatusEnum.PENDING, SubscriptionStatusEnum.SCHEDULED],
+        )
+        for sub in preparatory:
+            subId = sub["id"]
+            currentStatus = SubscriptionStatusEnum(sub["status"])
+            stripeSubId = sub.get("stripeSubscriptionId")
+
+            if stripeSubId and currentStatus == SubscriptionStatusEnum.SCHEDULED:
+                try:
+                    from modules.shared.stripeClient import getStripeClient
+                    stripe = getStripeClient()
+                    stripe.Subscription.cancel(stripeSubId)
+                except Exception as e:
+                    logger.error("Failed to cancel Stripe sub %s during cleanup: %s", stripeSubId, e)
+
+            self._interface.transitionStatus(subId, currentStatus, SubscriptionStatusEnum.EXPIRED)
+            logger.info("Cleaned up %s subscription %s for mandate %s", currentStatus.value, subId, mandateId)
+
+    def _expireOperative(self, subscriptionId: str, mandateId: str) -> None:
+        """Expire the current operative subscription (used when a free/trial plan replaces it)."""
+        sub = self._interface.getById(subscriptionId)
+        if not sub:
+            return
+        currentStatus = SubscriptionStatusEnum(sub["status"])
+        if currentStatus in OPERATIVE_STATUSES:
+            stripeSubId = sub.get("stripeSubscriptionId")
+            if stripeSubId:
+                try:
+                    from modules.shared.stripeClient import getStripeClient
+                    stripe = getStripeClient()
+                    stripe.Subscription.cancel(stripeSubId)
+                except Exception as e:
+                    logger.error("Failed to cancel Stripe sub %s: %s", stripeSubId, e)
+            self._interface.transitionStatus(subscriptionId, currentStatus, SubscriptionStatusEnum.EXPIRED)
+
+    def _createCheckoutSession(
+        self, mandateId: str, plan: SubscriptionPlan, subRecord: Dict[str, Any],
+        currentOperative: Optional[Dict[str, Any]], returnUrl: str,
+    ) -> str:
+        """Create a Stripe Checkout Session. If a predecessor exists, delays billing
+        via trial_end to start after the predecessor's period end."""
+        from modules.shared.stripeClient import getStripeClient
+        from modules.serviceCenter.services.serviceSubscription.stripeBootstrap import getStripePricesForPlan
+
+        stripe = getStripeClient()
+        priceMapping = getStripePricesForPlan(plan.planKey)
+        if not priceMapping or (not priceMapping.stripePriceIdUsers and not priceMapping.stripePriceIdInstances):
+            raise ValueError(f"Stripe Price IDs not provisioned for plan {plan.planKey}")
+
+        stripeCustomerId = self._resolveStripeCustomer(mandateId)
+        if not stripeCustomerId:
+            raise ValueError(f"Could not resolve Stripe customer for mandate {mandateId}")
+
+        activeUsers = self._interface.countActiveUsers(mandateId)
+        activeInstances = self._interface.countActiveFeatureInstances(mandateId)
+
+        lineItems = []
+        if priceMapping.stripePriceIdUsers:
+            lineItems.append({"price": priceMapping.stripePriceIdUsers, "quantity": max(activeUsers, 1)})
+        if priceMapping.stripePriceIdInstances and activeInstances > 0:
+            lineItems.append({"price": priceMapping.stripePriceIdInstances, "quantity": activeInstances})
+
+        if not returnUrl:
+            raise ValueError("returnUrl is required for paid subscription checkout")
+
+        from urllib.parse import urlparse
+        parsedReturn = urlparse(returnUrl)
+        platformUrl = f"{parsedReturn.scheme}://{parsedReturn.netloc}" if parsedReturn.scheme else ""
+
+        separator = "&" if "?" in returnUrl else "?"
+        successUrl = f"{returnUrl}{separator}success=true&session_id={{CHECKOUT_SESSION_ID}}"
+        cancelUrl = f"{returnUrl}{separator}canceled=true"
+
+        subscriptionData: Dict[str, Any] = {
+            "metadata": {
+                "mandateId": mandateId,
+                "subscriptionRecordId": subRecord["id"],
+                "planKey": plan.planKey,
+                "platformUrl": platformUrl,
+            },
+        }
+
+        if currentOperative and currentOperative.get("currentPeriodEnd"):
+            periodEnd = currentOperative["currentPeriodEnd"]
+            if isinstance(periodEnd, str):
+                periodEnd = datetime.fromisoformat(periodEnd)
+            trialEndTs = int(periodEnd.timestamp())
+            subscriptionData["trial_end"] = trialEndTs
+            self._interface.updateFields(subRecord["id"], {"effectiveFrom": periodEnd.isoformat()})
+
+        session = stripe.checkout.Session.create(
+            mode="subscription",
+            customer=stripeCustomerId,
+            line_items=lineItems,
+            success_url=successUrl,
+            cancel_url=cancelUrl,
+            subscription_data=subscriptionData,
+        )
+
+        if not session or not session.url:
+            raise ValueError("Stripe Checkout Session creation failed")
+
+        logger.info("Checkout session %s created for mandate %s, plan %s", session.id, mandateId, plan.planKey)
+        return session.url
+
+    def _resolveStripeCustomer(self, mandateId: str) -> Optional[str]:
+        try:
+            from modules.interfaces.interfaceDbBilling import getInterface as getBillingInterface
+            billingIf = getBillingInterface(self.currentUser, mandateId)
+            settings = billingIf.getSettings(mandateId)
+            if not settings:
+                return None
+            customerId = settings.get("stripeCustomerId")
+            if customerId:
+                return customerId
+
+            from modules.shared.stripeClient import getStripeClient
+            stripe = getStripeClient()
+
+            mandateLabel = mandateId
+            try:
+                from modules.datamodels.datamodelUam import Mandate
+                from modules.security.rootAccess import getRootDbAppConnector
+                appDb = getRootDbAppConnector()
+                rows = appDb.getRecordset(Mandate, recordFilter={"id": mandateId})
+                if rows:
+                    mandateLabel = rows[0].get("label") or rows[0].get("name") or mandateId
+            except Exception:
+                pass
+
+            customer = stripe.Customer.create(name=mandateLabel, metadata={"mandateId": mandateId})
+            billingIf.updateSettings(settings["id"], {"stripeCustomerId": customer.id})
+            logger.info("Stripe customer %s created for mandate %s", customer.id, mandateId)
+            return customer.id
+        except Exception as e:
+            logger.error("_resolveStripeCustomer(%s) failed: %s", mandateId, e)
+            return None
+
+    # =========================================================================
+    # T7: Cancel (set recurring=false)
+    # =========================================================================
+
+    def cancelSubscription(self, subscriptionId: str) -> Dict[str, Any]:
+        """Cancel a subscription (T7: set recurring=false, Stripe cancel_at_period_end).
+        The subscription stays ACTIVE until its period ends."""
+        sub = self._interface.getById(subscriptionId)
+        if not sub:
+            raise ValueError(f"Subscription {subscriptionId} not found")
+
+        status = sub.get("status", "")
+        mandateId = sub["mandateId"]
+
+        if status == SubscriptionStatusEnum.PENDING.value:
+            result = self._interface.transitionStatus(
+                subscriptionId, SubscriptionStatusEnum.PENDING, SubscriptionStatusEnum.EXPIRED,
+            )
+            self.invalidateCache(mandateId)
+            return result
+
+        if status == SubscriptionStatusEnum.SCHEDULED.value:
+            stripeSubId = sub.get("stripeSubscriptionId")
+            if stripeSubId:
+                try:
+                    from modules.shared.stripeClient import getStripeClient
+                    stripe = getStripeClient()
+                    stripe.Subscription.cancel(stripeSubId)
+                except Exception as e:
+                    logger.error("Failed to cancel Stripe sub %s: %s", stripeSubId, e)
+            result = self._interface.transitionStatus(
+                subscriptionId, SubscriptionStatusEnum.SCHEDULED, SubscriptionStatusEnum.EXPIRED,
+            )
+            self.invalidateCache(mandateId)
+            return result
+
+        if status != SubscriptionStatusEnum.ACTIVE.value:
+            raise ValueError(f"Cannot cancel subscription in status {status}")
+
+        if not sub.get("recurring", True):
+            raise ValueError("Subscription is already cancelled (non-recurring)")
+
+        stripeSubId = sub.get("stripeSubscriptionId")
+        if stripeSubId:
+            try:
+                from modules.shared.stripeClient import getStripeClient
+                stripe = getStripeClient()
+                stripe.Subscription.modify(stripeSubId, cancel_at_period_end=True)
+            except Exception as e:
+                logger.error("Failed to set cancel_at_period_end for %s: %s", stripeSubId, e)
+
+        result = self._interface.updateFields(subscriptionId, {"recurring": False})
+        self.invalidateCache(mandateId)
+
+        plan = _getPlan(sub.get("planKey", ""))
+        _notifySubscriptionChange(mandateId, "cancelled", plan)
+        return result
+
+    # =========================================================================
+    # T8: Reactivate (set recurring=true)
+    # =========================================================================
+
+    def reactivateSubscription(self, subscriptionId: str) -> Dict[str, Any]:
+        """Reactivate a cancelled subscription before its period ends (T8: recurring=true)."""
+        sub = self._interface.getById(subscriptionId)
+        if not sub:
+            raise ValueError(f"Subscription {subscriptionId} not found")
+
+        if sub.get("status") != SubscriptionStatusEnum.ACTIVE.value:
+            raise ValueError(f"Can only reactivate ACTIVE subscriptions, got {sub.get('status')}")
+        if sub.get("recurring", True):
+            raise ValueError("Subscription is already recurring")
+
+        periodEnd = sub.get("currentPeriodEnd")
+        if periodEnd:
+            if isinstance(periodEnd, str):
+                periodEnd = datetime.fromisoformat(periodEnd)
+            if periodEnd <= datetime.now(timezone.utc):
+                raise ValueError("Cannot reactivate — period has already ended")
+
+        stripeSubId = sub.get("stripeSubscriptionId")
+        if stripeSubId:
+            try:
+                from modules.shared.stripeClient import getStripeClient
+                stripe = getStripeClient()
+                stripe.Subscription.modify(stripeSubId, cancel_at_period_end=False)
+            except Exception as e:
+                logger.error("Failed to reactivate Stripe sub %s: %s", stripeSubId, e)
+
+        result = self._interface.updateFields(subscriptionId, {"recurring": True})
+        self.invalidateCache(sub["mandateId"])
+        return result
+
+    # =========================================================================
+    # T13: Sysadmin force-cancel
+    # =========================================================================
+
+    def forceCancel(self, subscriptionId: str) -> Dict[str, Any]:
+        """Sysadmin force-cancel: immediately expire any non-terminal subscription."""
+        sub = self._interface.getById(subscriptionId)
+        if not sub:
+            raise ValueError(f"Subscription {subscriptionId} not found")
+
+        stripeSubId = sub.get("stripeSubscriptionId")
+        if stripeSubId:
+            try:
+                from modules.shared.stripeClient import getStripeClient
+                stripe = getStripeClient()
+                stripe.Subscription.cancel(stripeSubId)
+            except Exception as e:
+                logger.error("Failed to cancel Stripe sub %s: %s", stripeSubId, e)
+
+        result = self._interface.forceExpire(subscriptionId)
+        self.invalidateCache(sub["mandateId"])
+        return result
+
+    # =========================================================================
+    # T6: Trial expiry
+    # =========================================================================
+
+    def handleTrialExpiry(self, subscriptionId: str) -> None:
+        """Expire a trial subscription (T6: TRIALING -> EXPIRED)."""
+        sub = self._interface.getById(subscriptionId)
+        if not sub or sub.get("status") != SubscriptionStatusEnum.TRIALING.value:
+            return
+
+        self._interface.transitionStatus(
+            subscriptionId, SubscriptionStatusEnum.TRIALING, SubscriptionStatusEnum.EXPIRED,
+        )
+        self.invalidateCache(sub["mandateId"])
+
+        plan = _getPlan(sub.get("planKey", ""))
+        successorPlan = _getPlan(plan.successorPlanKey) if plan and plan.successorPlanKey else None
+        _notifySubscriptionChange(sub["mandateId"], "trial_expired", successorPlan)
+        logger.info("Trial expired for subscription %s", subscriptionId)
+
+    # =========================================================================
+    # Stripe quantity sync
+    # =========================================================================
+
+    def syncStripeQuantity(self, subscriptionId: str):
+        self._interface.syncQuantityToStripe(subscriptionId)
+
+
+# ============================================================================
+# Notifications
+# ============================================================================
+
+def _notifySubscriptionChange(
+    mandateId: str,
+    event: str,
+    plan: Optional[SubscriptionPlan] = None,
+    subscriptionRecord: Optional[Dict[str, Any]] = None,
+    platformUrl: str = "",
+) -> None:
+    try:
+        from modules.shared.notifyMandateAdmins import notifyMandateAdmins
+
+        planLabel = (plan.title.get("de") or plan.title.get("en") or plan.planKey) if plan else "—"
+        platformHint = f"Plattform: {platformUrl}" if platformUrl else ""
+
+        rawHtmlBlock: Optional[str] = None
+
+        if event == "activated" and plan and subscriptionRecord:
+            rawHtmlBlock = _buildInvoiceSummaryHtml(plan, subscriptionRecord, mandateId, platformUrl)
+
+        templates: Dict[str, Dict[str, Any]] = {
+            "activated": {
+                "subject": f"[PowerOn] Abonnement aktiviert — {planLabel}",
+                "headline": "Abonnement aktiviert",
+                "paragraphs": [
+                    p for p in [
+                        f"Das Abonnement wurde auf den Plan «{planLabel}» aktiviert.",
+                        platformHint,
+                        "Sie können Ihr Abonnement jederzeit unter Billing-Verwaltung › Abonnement einsehen und verwalten.",
+                    ] if p
+                ],
+            },
+            "cancelled": {
+                "subject": f"[PowerOn] Abonnement gekündigt — {planLabel}",
+                "headline": "Abonnement gekündigt",
+                "paragraphs": [
+                    p for p in [
+                        f"Das Abonnement «{planLabel}» wurde gekündigt.",
+                        platformHint,
+                        "Die Kündigung wird zum Ende der aktuellen bezahlten Periode wirksam. Bis dahin bleibt der volle Zugang bestehen.",
+                    ] if p
+                ],
+            },
+            "trial_expired": {
+                "subject": "[PowerOn] Testphase abgelaufen",
+                "headline": "Testphase abgelaufen",
+                "paragraphs": [
+                    p for p in [
+                        "Die kostenlose Testphase ist abgelaufen.",
+                        platformHint,
+                        "Bitte wählen Sie einen Plan unter Billing-Verwaltung › Abonnement, damit der Zugang nicht unterbrochen wird.",
+                    ] if p
+                ],
+            },
+            "payment_failed": {
+                "subject": f"[PowerOn] Zahlung fehlgeschlagen — {planLabel}",
+                "headline": "Zahlung fehlgeschlagen",
+                "paragraphs": [
+                    p for p in [
+                        f"Die Zahlung für das Abonnement «{planLabel}» ist fehlgeschlagen.",
+                        platformHint,
+                        "Bitte aktualisieren Sie Ihr Zahlungsmittel unter Billing-Verwaltung.",
+                    ] if p
+                ],
+            },
+        }
+
+        tpl = templates.get(event, {
+            "subject": f"[PowerOn] Abonnement-Änderung — {planLabel}",
+            "headline": "Abonnement-Änderung",
+            "paragraphs": [f"Änderung am Abonnement «{planLabel}»."],
+        })
+
+        notifyMandateAdmins(
+            mandateId, tpl["subject"], tpl["headline"], tpl["paragraphs"],
+            rawHtmlBlock=rawHtmlBlock,
+        )
+    except Exception as e:
+        logger.error("_notifySubscriptionChange failed for mandate %s event %s: %s", mandateId, event, e)
+
+
+def _buildInvoiceSummaryHtml(
+    plan: SubscriptionPlan,
+    subRecord: Dict[str, Any],
+    mandateId: str,
+    platformUrl: str = "",
+) -> str:
+    """Build an HTML invoice summary block for inclusion in the activation email."""
+    import html as htmlmod
+    from modules.interfaces.interfaceDbSubscription import _getRootInterface as getSubRootInterface
+
+    subInterface = getSubRootInterface()
+    userCount = subInterface.countActiveUsers(mandateId)
+    instanceCount = subInterface.countActiveFeatureInstances(mandateId)
+
+    userPrice = plan.pricePerUserCHF
+    instancePrice = plan.pricePerFeatureInstanceCHF
+    userTotal = userCount * userPrice
+    instanceTotal = instanceCount * instancePrice
+    netTotal = userTotal + instanceTotal
+
+    periodLabel = {"MONTHLY": "Monatlich", "YEARLY": "Jährlich"}.get(plan.billingPeriod, plan.billingPeriod)
+
+    def _chf(amount: float) -> str:
+        return f"CHF {amount:,.2f}".replace(",", "'")
+
+    rows = ""
+    if userPrice > 0:
+        rows += (
+            f'<tr><td style="padding:6px 0;color:#333;">Benutzer-Lizenzen</td>'
+            f'<td style="padding:6px 8px;color:#555;text-align:right;">{userCount} × {_chf(userPrice)}</td>'
+            f'<td style="padding:6px 0;color:#333;text-align:right;font-weight:600;">{_chf(userTotal)}</td></tr>\n'
+        )
+    if instancePrice > 0:
+        rows += (
+            f'<tr><td style="padding:6px 0;color:#333;">Feature-Instanzen</td>'
+            f'<td style="padding:6px 8px;color:#555;text-align:right;">{instanceCount} × {_chf(instancePrice)}</td>'
+            f'<td style="padding:6px 0;color:#333;text-align:right;font-weight:600;">{_chf(instanceTotal)}</td></tr>\n'
+        )
+
+    invoiceLink = ""
+    stripeSubId = subRecord.get("stripeSubscriptionId")
+    if stripeSubId:
+        try:
+            from modules.shared.stripeClient import getStripeClient
+            stripe = getStripeClient()
+            invoices = stripe.Invoice.list(subscription=stripeSubId, limit=1)
+            if invoices.data:
+                hostedUrl = invoices.data[0].get("hosted_invoice_url", "")
+                if hostedUrl:
+                    invoiceLink = (
+                        f'<p style="margin:12px 0 0 0;font-size:14px;">'
+                        f'<a href="{htmlmod.escape(hostedUrl)}" style="color:#3b82f6;text-decoration:underline;">'
+                        f'Vollständige Rechnung mit MwSt-Ausweis anzeigen</a></p>\n'
+                    )
+        except Exception as e:
+            logger.warning("Could not fetch Stripe invoice URL for sub %s: %s", stripeSubId, e)
+
+    return (
+        f'<table style="width:100%;border-collapse:collapse;font-size:14px;margin:8px 0;">'
+        f'<thead><tr style="border-bottom:2px solid #e5e7eb;">'
+        f'<th style="text-align:left;padding:8px 0;color:#6b7280;font-weight:500;">Position</th>'
+        f'<th style="text-align:right;padding:8px;color:#6b7280;font-weight:500;">Menge × Preis</th>'
+        f'<th style="text-align:right;padding:8px 0;color:#6b7280;font-weight:500;">Total</th>'
+        f'</tr></thead>'
+        f'<tbody>{rows}</tbody>'
+        f'<tfoot><tr style="border-top:2px solid #1a1a2e;">'
+        f'<td style="padding:10px 0;font-weight:700;color:#1a1a2e;">Netto-Total ({periodLabel})</td>'
+        f'<td></td>'
+        f'<td style="padding:10px 0;text-align:right;font-weight:700;color:#1a1a2e;font-size:16px;">{_chf(netTotal)}</td>'
+        f'</tr></tfoot>'
+        f'</table>'
+        f'{invoiceLink}'
+    )
+
+
+# ============================================================================
+# Exception Classes
+# ============================================================================
+
+SUBSCRIPTION_USER_ACTION_UPGRADE = "UPGRADE_SUBSCRIPTION"
+SUBSCRIPTION_USER_ACTION_REACTIVATE = "REACTIVATE_SUBSCRIPTION"
+SUBSCRIPTION_USER_ACTION_ADD_PAYMENT = "ADD_PAYMENT_METHOD"
+
+SUBSCRIPTION_REASONS = {
+    "SUBSCRIPTION_INACTIVE",
+    "SUBSCRIPTION_PAYMENT_REQUIRED",
+    "SUBSCRIPTION_PAYMENT_PENDING",
+    "SUBSCRIPTION_EXPIRED",
+}
+
+
+def _subscriptionReasonForStatus(status: SubscriptionStatusEnum) -> str:
+    if status == SubscriptionStatusEnum.PENDING:
+        return "SUBSCRIPTION_PAYMENT_PENDING"
+    if status == SubscriptionStatusEnum.PAST_DUE:
+        return "SUBSCRIPTION_PAYMENT_REQUIRED"
+    if status == SubscriptionStatusEnum.EXPIRED:
+        return "SUBSCRIPTION_EXPIRED"
+    return "SUBSCRIPTION_INACTIVE"
+
+
+def _subscriptionUserActionForStatus(status: SubscriptionStatusEnum) -> str:
+    if status in (SubscriptionStatusEnum.PAST_DUE, SubscriptionStatusEnum.PENDING):
+        return SUBSCRIPTION_USER_ACTION_ADD_PAYMENT
+    return SUBSCRIPTION_USER_ACTION_UPGRADE
+
+
+class SubscriptionInactiveException(Exception):
+    def __init__(self, status: SubscriptionStatusEnum, mandateId: str = "", message: Optional[str] = None):
+        self.status = status
+        self.mandateId = mandateId
+        self.reason = _subscriptionReasonForStatus(status)
+        self.userAction = _subscriptionUserActionForStatus(status)
+        self.message = message or (
+            "Kein aktives Abonnement für diesen Mandanten. Bitte wählen Sie einen Plan unter Billing."
+        )
+        super().__init__(self.message)
+
+    def toClientDict(self) -> Dict[str, Any]:
+        out: Dict[str, Any] = {
+            "error": self.reason, "message": self.message,
+            "userAction": self.userAction, "subscriptionUiPath": "/admin/billing?tab=subscription",
+        }
+        if self.mandateId:
+            out["mandateId"] = self.mandateId
+        return out
+
+
+class SubscriptionCapacityException(Exception):
+    def __init__(self, resourceType: str, currentCount: int, maxAllowed: int, message: Optional[str] = None):
+        self.resourceType = resourceType
+        self.currentCount = currentCount
+        self.maxAllowed = maxAllowed
+        self.message = message or (
+            f"Ihr Plan erlaubt maximal {maxAllowed} {'Benutzer' if resourceType == 'users' else 'Feature-Instanzen'} "
+            f"(aktuell {currentCount}). Bitte wechseln Sie zu einem grösseren Plan."
+        )
+        super().__init__(self.message)
+
+    def toClientDict(self) -> Dict[str, Any]:
+        return {
+            "error": f"SUBSCRIPTION_{self.resourceType.upper()}_LIMIT",
+            "currentCount": self.currentCount, "maxAllowed": self.maxAllowed,
+            "message": self.message, "userAction": SUBSCRIPTION_USER_ACTION_UPGRADE,
+            "subscriptionUiPath": "/admin/billing?tab=subscription",
+        }
+
+
+SubscriptionService.SubscriptionInactiveException = SubscriptionInactiveException
+SubscriptionService.SubscriptionCapacityException = SubscriptionCapacityException
--- a/modules/serviceCenter/services/serviceSubscription/stripeBootstrap.py
+++ b/modules/serviceCenter/services/serviceSubscription/stripeBootstrap.py
@ -0,0 +1,214 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Auto-provision Stripe Products and Prices from the built-in plan catalog.
+
+Creates separate Stripe Products for user licenses and feature instances
+so that invoice line items show clear, descriptive names:
+  - "Benutzer-Lizenzen"
+  - "Feature-Instanzen"
+
+Idempotent — safe to call on every startup.
+"""
+
+import logging
+from typing import Dict, Optional
+
+from modules.connectors.connectorDbPostgre import DatabaseConnector
+from modules.shared.configuration import APP_CONFIG
+from modules.datamodels.datamodelSubscription import (
+    BUILTIN_PLANS,
+    SubscriptionPlan,
+    BillingPeriodEnum,
+    StripePlanPrice,
+)
+
+logger = logging.getLogger(__name__)
+
+_BILLING_DATABASE = "poweron_billing"
+_METADATA_KEY = "poweron_plan_key"
+_METADATA_LINE_TYPE = "poweron_line_type"
+
+_PERIOD_TO_STRIPE = {
+    BillingPeriodEnum.MONTHLY: {"interval": "month", "interval_count": 1},
+    BillingPeriodEnum.YEARLY: {"interval": "year", "interval_count": 1},
+}
+
+
+def _getBillingDb() -> DatabaseConnector:
+    return DatabaseConnector(
+        dbDatabase=_BILLING_DATABASE,
+        dbHost=APP_CONFIG.get("DB_HOST", "localhost"),
+        dbPort=int(APP_CONFIG.get("DB_PORT", "5432")),
+        dbUser=APP_CONFIG.get("DB_USER"),
+        dbPassword=APP_CONFIG.get("DB_PASSWORD_SECRET"),
+    )
+
+
+def _loadExistingMappings(db: DatabaseConnector) -> Dict[str, StripePlanPrice]:
+    try:
+        rows = db.getRecordset(StripePlanPrice)
+        result = {}
+        for row in rows:
+            pk = row.get("planKey")
+            if pk:
+                result[pk] = StripePlanPrice(**{k: v for k, v in row.items() if not k.startswith("_")})
+        return result
+    except Exception as e:
+        logger.warning("Could not load StripePlanPrice records: %s", e)
+        return {}
+
+
+def _findStripeProduct(stripe, planKey: str, lineType: str) -> Optional[str]:
+    """Search Stripe for a product tagged with plan key + line type."""
+    try:
+        products = stripe.Product.search(
+            query=f'metadata["{_METADATA_KEY}"]:"{planKey}" AND metadata["{_METADATA_LINE_TYPE}"]:"{lineType}"',
+            limit=1,
+        )
+        if products.data:
+            return products.data[0].id
+    except Exception:
+        try:
+            products = stripe.Product.search(
+                query=f'metadata["{_METADATA_KEY}"]:"{planKey}"',
+                limit=10,
+            )
+            for p in products.data:
+                meta = p.get("metadata") or {}
+                if meta.get(_METADATA_LINE_TYPE) == lineType:
+                    return p.id
+        except Exception:
+            pass
+    return None
+
+
+def _createStripeProduct(stripe, name: str, description: str, planKey: str, lineType: str) -> str:
+    product = stripe.Product.create(
+        name=name,
+        description=description,
+        metadata={_METADATA_KEY: planKey, _METADATA_LINE_TYPE: lineType},
+    )
+    logger.info("Created Stripe Product %s: %s (%s/%s)", product.id, name, planKey, lineType)
+    return product.id
+
+
+def _findExistingStripePrice(stripe, productId: str, unitAmount: int, interval: str) -> Optional[str]:
+    try:
+        prices = stripe.Price.list(product=productId, active=True, limit=50)
+        for p in prices.data:
+            recurring = p.get("recurring") or {}
+            if p.get("unit_amount") == unitAmount and recurring.get("interval") == interval:
+                return p.id
+    except Exception:
+        pass
+    return None
+
+
+def _createStripePrice(stripe, productId: str, unitAmountCHF: float, interval: str, nickname: str) -> str:
+    price = stripe.Price.create(
+        product=productId,
+        unit_amount=int(unitAmountCHF * 100),
+        currency="chf",
+        recurring={"interval": interval},
+        nickname=nickname,
+    )
+    logger.info("Created Stripe Price %s (%s, %s CHF/%s)", price.id, nickname, unitAmountCHF, interval)
+    return price.id
+
+
+def bootstrapStripePrices() -> None:
+    """Ensure all paid plans have separate Stripe Products for users and instances."""
+    try:
+        from modules.shared.stripeClient import getStripeClient
+        stripe = getStripeClient()
+    except ValueError as e:
+        logger.error("Stripe not configured — cannot bootstrap subscription prices: %s", e)
+        return
+
+    db = _getBillingDb()
+    existing = _loadExistingMappings(db)
+
+    for planKey, plan in BUILTIN_PLANS.items():
+        if plan.billingPeriod == BillingPeriodEnum.NONE:
+            continue
+        if plan.pricePerUserCHF == 0 and plan.pricePerFeatureInstanceCHF == 0:
+            continue
+
+        stripePeriod = _PERIOD_TO_STRIPE.get(plan.billingPeriod)
+        if not stripePeriod:
+            continue
+
+        interval = stripePeriod["interval"]
+
+        if planKey in existing:
+            mapping = existing[planKey]
+            hasAllPrices = mapping.stripePriceIdUsers and mapping.stripePriceIdInstances
+            hasAllProducts = mapping.stripeProductIdUsers and mapping.stripeProductIdInstances
+            if hasAllPrices and hasAllProducts:
+                logger.debug("Stripe prices already configured for plan %s", planKey)
+                continue
+
+        productIdUsers = None
+        productIdInstances = None
+        priceIdUsers = None
+        priceIdInstances = None
+
+        if plan.pricePerUserCHF > 0:
+            productIdUsers = _findStripeProduct(stripe, planKey, "users")
+            if not productIdUsers:
+                productIdUsers = _createStripeProduct(
+                    stripe, "Benutzer-Lizenzen", f"Benutzer-Lizenzen für {plan.title.get('de', planKey)}",
+                    planKey, "users",
+                )
+            priceIdUsers = _findExistingStripePrice(stripe, productIdUsers, int(plan.pricePerUserCHF * 100), interval)
+            if not priceIdUsers:
+                priceIdUsers = _createStripePrice(
+                    stripe, productIdUsers, plan.pricePerUserCHF, interval, f"{planKey} — Benutzer-Lizenz",
+                )
+
+        if plan.pricePerFeatureInstanceCHF > 0:
+            productIdInstances = _findStripeProduct(stripe, planKey, "instances")
+            if not productIdInstances:
+                productIdInstances = _createStripeProduct(
+                    stripe, "Feature-Instanzen", f"Feature-Instanzen für {plan.title.get('de', planKey)}",
+                    planKey, "instances",
+                )
+            priceIdInstances = _findExistingStripePrice(
+                stripe, productIdInstances, int(plan.pricePerFeatureInstanceCHF * 100), interval,
+            )
+            if not priceIdInstances:
+                priceIdInstances = _createStripePrice(
+                    stripe, productIdInstances, plan.pricePerFeatureInstanceCHF, interval,
+                    f"{planKey} — Feature-Instanz",
+                )
+
+        persistData = {
+            "stripeProductId": "",
+            "stripeProductIdUsers": productIdUsers,
+            "stripeProductIdInstances": productIdInstances,
+            "stripePriceIdUsers": priceIdUsers,
+            "stripePriceIdInstances": priceIdInstances,
+        }
+
+        if planKey in existing:
+            db.recordModify(StripePlanPrice, existing[planKey].id, persistData)
+        else:
+            db.recordCreate(StripePlanPrice, StripePlanPrice(planKey=planKey, **persistData).model_dump())
+
+        logger.info(
+            "Stripe bootstrapped for %s: users=%s/%s, instances=%s/%s",
+            planKey, productIdUsers, priceIdUsers, productIdInstances, priceIdInstances,
+        )
+
+
+def getStripePricesForPlan(planKey: str) -> Optional[StripePlanPrice]:
+    """Load the persisted Stripe IDs for a plan."""
+    try:
+        db = _getBillingDb()
+        rows = db.getRecordset(StripePlanPrice, recordFilter={"planKey": planKey})
+        if rows:
+            return StripePlanPrice(**{k: v for k, v in rows[0].items() if not k.startswith("_")})
+    except Exception as e:
+        logger.error("Error loading Stripe prices for plan %s: %s", planKey, e)
+    return None
--- a/modules/shared/configuration.py
+++ b/modules/shared/configuration.py
@ -66,7 +66,7 @@ class Configuration:
        self._configMtime = currentMtime

        try:
-            with open(configPath, 'r') as f:
+            with open(configPath, 'r', encoding='utf-8') as f:
                lines = f.readlines()
                
            i = 0
--- a/modules/shared/notifyMandateAdmins.py
+++ b/modules/shared/notifyMandateAdmins.py
@ -0,0 +1,285 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Central notification utility for mandate administrators.
+
+All mandate-level notifications (subscription changes, billing warnings, etc.)
+MUST go through notifyMandateAdmins() to ensure consistent recipient resolution
+and delivery.
+
+Recipients are the union of:
+1. BillingSettings.notifyEmails for the mandate (configured contact addresses)
+2. All users with the mandate-level "admin" RBAC role
+"""
+
+from __future__ import annotations
+
+import html
+import json
+import logging
+from typing import Any, Dict, List, Optional, Set
+
+from modules.datamodels.datamodelMessaging import MessagingChannel
+from modules.interfaces.interfaceMessaging import getInterface as getMessagingInterface
+
+logger = logging.getLogger(__name__)
+
+
+# ============================================================================
+# Recipient resolution
+# ============================================================================
+
+
+def _normalizeEmailList(raw: Any) -> List[str]:
+    """Parse notifyEmails which can be a list, JSON string, or single address."""
+    if raw is None:
+        return []
+    if isinstance(raw, list):
+        return [str(e).strip().lower() for e in raw if str(e).strip()]
+    if isinstance(raw, str):
+        s = raw.strip()
+        if not s:
+            return []
+        if s.startswith("["):
+            try:
+                parsed = json.loads(s)
+                if isinstance(parsed, list):
+                    return [str(e).strip().lower() for e in parsed if str(e).strip()]
+            except Exception:
+                pass
+        return [s.lower()]
+    return []
+
+
+def _resolveMandateContactEmails(mandateId: str) -> List[str]:
+    """Get the configured notifyEmails from BillingSettings."""
+    try:
+        from modules.interfaces.interfaceDbBilling import getInterface as getBillingInterface
+        from modules.security.rootAccess import getRootUser
+        billingIf = getBillingInterface(getRootUser(), mandateId)
+        settings = billingIf.getSettings(mandateId) or {}
+        return _normalizeEmailList(settings.get("notifyEmails"))
+    except Exception as e:
+        logger.warning("Could not resolve BillingSettings.notifyEmails for mandate %s: %s", mandateId, e)
+        return []
+
+
+def _resolveMandateAdminEmails(mandateId: str) -> List[str]:
+    """Resolve all admin users of a mandate via RBAC and return their emails."""
+    emails: List[str] = []
+    try:
+        from modules.interfaces.interfaceDbApp import getRootInterface
+        rootIf = getRootInterface()
+        userMandates = rootIf.getUserMandatesByMandate(mandateId)
+        for um in userMandates:
+            if not getattr(um, "enabled", True):
+                continue
+            umId = str(getattr(um, "id", ""))
+            userId = getattr(um, "userId", None)
+            if not userId:
+                continue
+            roleIds = rootIf.getRoleIdsForUserMandate(umId)
+            isAdmin = False
+            for roleId in roleIds:
+                role = rootIf.getRole(roleId)
+                if role and role.roleLabel == "admin" and not role.featureInstanceId:
+                    isAdmin = True
+                    break
+            if not isAdmin:
+                continue
+            user = rootIf.getUser(str(userId))
+            if user and user.email:
+                emails.append(user.email.strip().lower())
+    except Exception as e:
+        logger.warning("Could not resolve admin emails for mandate %s: %s", mandateId, e)
+    return emails
+
+
+def _resolveAllRecipients(mandateId: str) -> List[str]:
+    """Union of BillingSettings.notifyEmails + all mandate admin user emails, deduplicated."""
+    seen: Set[str] = set()
+    result: List[str] = []
+    for email in _resolveMandateContactEmails(mandateId) + _resolveMandateAdminEmails(mandateId):
+        if email and email not in seen:
+            seen.add(email)
+            result.append(email)
+    return result
+
+
+# ============================================================================
+# Mandate name resolution
+# ============================================================================
+
+
+def _resolveMandateName(mandateId: str) -> str:
+    """Return the human-readable mandate name (label or name), falling back to a short ID."""
+    try:
+        from modules.datamodels.datamodelUam import Mandate
+        from modules.security.rootAccess import getRootDbAppConnector
+        appDb = getRootDbAppConnector()
+        rows = appDb.getRecordset(Mandate, recordFilter={"id": mandateId})
+        if rows:
+            return rows[0].get("label") or rows[0].get("name") or mandateId[:8]
+    except Exception as e:
+        logger.warning("Could not resolve mandate name for %s: %s", mandateId, e)
+    return mandateId[:8]
+
+
+# ============================================================================
+# HTML email rendering
+# ============================================================================
+
+
+def _getOperatorInfo() -> Dict[str, str]:
+    """Load operator company data from config.ini."""
+    try:
+        from modules.shared.configuration import APP_CONFIG
+        return {
+            "companyName": APP_CONFIG.get("Operator_CompanyName", ""),
+            "address": APP_CONFIG.get("Operator_Address", ""),
+            "vatNumber": APP_CONFIG.get("Operator_VatNumber", ""),
+        }
+    except Exception:
+        return {"companyName": "", "address": "", "vatNumber": ""}
+
+
+def _renderHtmlEmail(
+    headline: str,
+    bodyParagraphs: List[str],
+    mandateName: str,
+    footerNote: Optional[str] = None,
+    rawHtmlBlock: Optional[str] = None,
+) -> str:
+    """Render a clean, professional HTML notification email.
+
+    Args:
+        rawHtmlBlock: Optional pre-formatted HTML inserted after bodyParagraphs (e.g. invoice table).
+    """
+    hl = html.escape(headline)
+    mn = html.escape(mandateName)
+
+    paragraphsHtml = ""
+    for p in bodyParagraphs:
+        escaped = html.escape(p).replace("\n", "<br>")
+        paragraphsHtml += f'<p style="margin: 0 0 14px 0; color: #333333;">{escaped}</p>\n'
+
+    rawBlock = ""
+    if rawHtmlBlock:
+        rawBlock = f'<div style="margin: 16px 0;">{rawHtmlBlock}</div>\n'
+
+    footer = ""
+    if footerNote:
+        footer = (
+            f'<p style="margin: 16px 0 0 0; font-size: 13px; color: #888888;">'
+            f'{html.escape(footerNote)}</p>\n'
+        )
+
+    operator = _getOperatorInfo()
+    operatorLine = ""
+    parts = [p for p in [operator["companyName"], operator["address"], operator["vatNumber"]] if p]
+    if parts:
+        operatorLine = (
+            f'<p style="margin: 4px 0 0 0; font-size: 11px; color: #b0b0b0; text-align: center;">'
+            f'{html.escape(" | ".join(parts))}</p>\n'
+        )
+
+    return f"""<!DOCTYPE html>
+<html lang="de">
+<head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"></head>
+<body style="margin: 0; padding: 0; background-color: #f4f4f7; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;">
+  <table role="presentation" width="100%" cellpadding="0" cellspacing="0" style="background-color: #f4f4f7; padding: 32px 16px;">
+    <tr><td align="center">
+      <table role="presentation" width="560" cellpadding="0" cellspacing="0" style="background-color: #ffffff; border-radius: 8px; overflow: hidden; box-shadow: 0 1px 3px rgba(0,0,0,0.08);">
+        <!-- Header -->
+        <tr><td style="background-color: #1a1a2e; padding: 24px 32px;">
+          <h1 style="margin: 0; font-size: 18px; font-weight: 600; color: #ffffff;">PowerOn</h1>
+        </td></tr>
+        <!-- Body -->
+        <tr><td style="padding: 32px;">
+          <h2 style="margin: 0 0 8px 0; font-size: 20px; font-weight: 600; color: #1a1a2e;">{hl}</h2>
+          <p style="margin: 0 0 24px 0; font-size: 14px; color: #6b7280;">Mandant: <strong>{mn}</strong></p>
+          <div style="font-size: 15px; line-height: 1.6;">
+            {paragraphsHtml}
+            {rawBlock}
+          </div>
+          {footer}
+        </td></tr>
+        <!-- Footer -->
+        <tr><td style="padding: 16px 32px; background-color: #f9fafb; border-top: 1px solid #e5e7eb;">
+          <p style="margin: 0; font-size: 12px; color: #9ca3af; text-align: center;">
+            Diese E-Mail wurde automatisch von PowerOn versendet.
+          </p>
+          {operatorLine}
+        </td></tr>
+      </table>
+    </td></tr>
+  </table>
+</body>
+</html>"""
+
+
+# ============================================================================
+# Public API
+# ============================================================================
+
+
+def notifyMandateAdmins(
+    mandateId: str,
+    subject: str,
+    headline: str,
+    bodyParagraphs: List[str],
+    *,
+    footerNote: Optional[str] = None,
+    rawHtmlBlock: Optional[str] = None,
+) -> int:
+    """
+    Send a styled HTML notification to all mandate admins and configured contacts.
+
+    Args:
+        mandateId: The mandate to notify admins for.
+        subject: Email subject line.
+        headline: Bold headline inside the email body.
+        bodyParagraphs: List of paragraph strings (plain text, auto-escaped).
+        footerNote: Optional small-print note below the main content.
+        rawHtmlBlock: Optional pre-formatted HTML block (e.g. invoice summary table).
+
+    Returns:
+        Number of recipients that were successfully notified.
+    """
+    if not mandateId:
+        return 0
+
+    recipients = _resolveAllRecipients(mandateId)
+    if not recipients:
+        logger.warning(
+            "notifyMandateAdmins: no recipients found for mandate %s "
+            "(no notifyEmails configured and no admin users with email)",
+            mandateId,
+        )
+        return 0
+
+    mandateName = _resolveMandateName(mandateId)
+    htmlMessage = _renderHtmlEmail(headline, bodyParagraphs, mandateName, footerNote, rawHtmlBlock)
+    messaging = getMessagingInterface()
+    successCount = 0
+
+    for to in recipients:
+        try:
+            ok = messaging.send(
+                channel=MessagingChannel.EMAIL,
+                recipient=to,
+                subject=subject,
+                message=htmlMessage,
+            )
+            if ok:
+                successCount += 1
+            else:
+                logger.warning("notifyMandateAdmins: send failed for %s", to)
+        except Exception as e:
+            logger.error("notifyMandateAdmins: error sending to %s: %s", to, e)
+
+    logger.info(
+        "notifyMandateAdmins: sent '%s' to %d/%d recipients for mandate %s (%s)",
+        subject, successCount, len(recipients), mandateId, mandateName,
+    )
+    return successCount
--- a/modules/shared/stripeClient.py
+++ b/modules/shared/stripeClient.py
@ -0,0 +1,38 @@
+# Copyright (c) 2025 Patrick Motsch
+# All rights reserved.
+"""
+Central Stripe SDK initialization.
+
+All Stripe interactions MUST use getStripeClient() to ensure consistent
+API key, API version, and fallback handling across billing and subscription flows.
+"""
+
+import logging
+from typing import Optional
+
+logger = logging.getLogger(__name__)
+
+_stripeInitialized = False
+
+
+def getStripeClient():
+    """
+    Initialize and return the configured Stripe SDK module.
+
+    Raises ValueError if no Stripe secret key is configured.
+    """
+    import stripe
+    from modules.shared.configuration import APP_CONFIG
+
+    apiVersion = APP_CONFIG.get("STRIPE_API_VERSION")
+    if apiVersion:
+        stripe.api_version = apiVersion
+
+    secretKey = APP_CONFIG.get("STRIPE_SECRET_KEY_SECRET") or APP_CONFIG.get("STRIPE_SECRET_KEY")
+    if not secretKey:
+        raise ValueError("STRIPE_SECRET_KEY_SECRET not configured")
+
+    stripe.api_key = secretKey
+    return stripe
+
+
--- a/modules/system/mainSystem.py
+++ b/modules/system/mainSystem.py
@ -190,7 +190,6 @@ NAVIGATION_SECTIONS = [
                        "path": "/admin/billing",
                        "order": 40,
                        "adminOnly": True,
-                        "sysAdminOnly": True,
                    },
                ],
            },