diff --git a/src/hooks/useMandateRoles.ts b/src/hooks/useMandateRoles.ts
index bf6ccbc..ba425cb 100644
--- a/src/hooks/useMandateRoles.ts
+++ b/src/hooks/useMandateRoles.ts
@@ -107,8 +107,9 @@ export function useMandateRoles() {
       if (Object.keys(paginationWithoutScope).length > 0) {
         queryParams.pagination = JSON.stringify(paginationWithoutScope);
       }
-      // Include templates by default for mandate roles view
-      queryParams.includeTemplates = 'true';
+      // Do NOT include feature template roles - they belong to Feature-Rollen page
+      // According to admin_ui_concept.md: Filter: featureCode=null AND featureInstanceId=null
+      queryParams.includeTemplates = 'false';
       // Include mandate-specific roles for the selected mandate
       if (mandateId) {
         queryParams.mandateId = mandateId;
diff --git a/src/pages/admin/AdminFeatureInstanceUsersPage.tsx b/src/pages/admin/AdminFeatureInstanceUsersPage.tsx
index 5a520ab..e026b91 100644
--- a/src/pages/admin/AdminFeatureInstanceUsersPage.tsx
+++ b/src/pages/admin/AdminFeatureInstanceUsersPage.tsx
@@ -7,7 +7,7 @@
 
 import React, { useState, useEffect, useMemo, useCallback } from 'react';
 import { useFeatureAccess, type FeatureAccessUser, type FeatureInstanceRole, type PaginationParams, type PaginationMetadata } from '../../hooks/useFeatureAccess';
-import { useUserMandates, type Mandate } from '../../hooks/useUserMandates';
+import { useUserMandates } from '../../hooks/useUserMandates';
 import { FormGeneratorTable } from '../../components/FormGenerator/FormGeneratorTable';
 import { FormGeneratorForm, type AttributeDefinition } from '../../components/FormGenerator/FormGeneratorForm';
 import { FaPlus, FaSync, FaUsers, FaBuilding, FaCube } from 'react-icons/fa';
@@ -22,7 +22,6 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
     loading,
     error,
     fetchFeatures,
-    fetchInstances,
     fetchInstanceUsers,
     addUserToInstance,
     removeUserFromInstance,
@@ -33,10 +32,19 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
   const { fetchMandates } = useUserMandates();
   const { showSuccess, showError } = useToast();
 
+  // Combined instance option type
+  interface CombinedInstanceOption {
+    mandateId: string;
+    instanceId: string;
+    mandateName: string;
+    instanceLabel: string;
+    featureCode: string;
+    combinedKey: string; // mandateId:instanceId for unique identification
+  }
+
   // State
-  const [mandates, setMandates] = useState<Mandate[]>([]);
-  const [selectedMandateId, setSelectedMandateId] = useState<string>('');
-  const [selectedInstanceId, setSelectedInstanceId] = useState<string>('');
+  const [combinedOptions, setCombinedOptions] = useState<CombinedInstanceOption[]>([]);
+  const [selectedCombinedKey, setSelectedCombinedKey] = useState<string>('');
   const [instanceUsers, setInstanceUsers] = useState<FeatureAccessUser[]>([]);
   const [instanceRoles, setInstanceRoles] = useState<FeatureInstanceRole[]>([]);
   const [allUsers, setAllUsers] = useState<Array<{ id: string; username: string; email?: string; fullName?: string }>>([]);
@@ -46,22 +54,63 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
   const [usersLoading, setUsersLoading] = useState(false);
   const [usersPagination, setUsersPagination] = useState<PaginationMetadata | null>(null);
 
-  // Load mandates and features on mount
+  // Extract mandateId and instanceId from combined key
+  const selectedMandateId = useMemo(() => {
+    if (!selectedCombinedKey) return '';
+    return selectedCombinedKey.split(':')[0] || '';
+  }, [selectedCombinedKey]);
+
+  const selectedInstanceId = useMemo(() => {
+    if (!selectedCombinedKey) return '';
+    return selectedCombinedKey.split(':')[1] || '';
+  }, [selectedCombinedKey]);
+
+  // Load mandates and features on mount, then build combined options
   useEffect(() => {
     fetchFeatures();
-    fetchMandates().then(setMandates);
+    const loadCombinedOptions = async () => {
+      const loadedMandates = await fetchMandates();
+      
+      // Load instances for all mandates in parallel
+      const allOptions: CombinedInstanceOption[] = [];
+      
+      for (const mandate of loadedMandates) {
+        try {
+          const response = await api.get('/api/features/instances', {
+            headers: { 'X-Mandate-Id': mandate.id }
+          });
+          const instanceList = response.data?.items || response.data || [];
+          
+          if (Array.isArray(instanceList)) {
+            for (const inst of instanceList) {
+              allOptions.push({
+                mandateId: mandate.id,
+                instanceId: inst.id,
+                mandateName: typeof mandate.name === 'string' ? mandate.name : (mandate.name?.de || mandate.name?.en || Object.values(mandate.name || {})[0] || mandate.id),
+                instanceLabel: inst.label || inst.id,
+                featureCode: inst.featureCode,
+                combinedKey: `${mandate.id}:${inst.id}`,
+              });
+            }
+          }
+        } catch (err) {
+          console.error(`Error loading instances for mandate ${mandate.id}:`, err);
+        }
+      }
+      
+      // Sort by mandate name, then by instance label
+      allOptions.sort((a, b) => {
+        const mandateCompare = a.mandateName.localeCompare(b.mandateName);
+        if (mandateCompare !== 0) return mandateCompare;
+        return a.instanceLabel.localeCompare(b.instanceLabel);
+      });
+      
+      setCombinedOptions(allOptions);
+    };
+    
+    loadCombinedOptions();
   }, [fetchFeatures, fetchMandates]);
 
-  // Load instances when mandate changes
-  useEffect(() => {
-    if (selectedMandateId) {
-      fetchInstances(selectedMandateId);
-      setSelectedInstanceId('');
-      setInstanceUsers([]);
-      setInstanceRoles([]);
-    }
-  }, [selectedMandateId, fetchInstances]);
-
   // Load users and roles when instance changes
   useEffect(() => {
     if (selectedMandateId && selectedInstanceId) {
@@ -297,14 +346,6 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
     setEditingUser(user);
   };
 
-  // Get mandate name
-  const getMandateName = (mandate: Mandate) => {
-    if (typeof mandate.name === 'object') {
-      return mandate.name.de || mandate.name.en || Object.values(mandate.name)[0] || mandate.id;
-    }
-    return mandate.name || mandate.id;
-  };
-
   // Get feature label
   const getFeatureLabel = (code: string) => {
     const feature = features.find(f => f.code === code);
@@ -316,12 +357,24 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
     return code;
   };
 
-  // Get selected instance info
+  // Get selected instance info from combined options
   const selectedInstance = useMemo(() => {
-    return instances.find(i => i.id === selectedInstanceId);
-  }, [instances, selectedInstanceId]);
+    const option = combinedOptions.find(o => o.combinedKey === selectedCombinedKey);
+    if (!option) return null;
+    return instances.find(i => i.id === option.instanceId) || {
+      id: option.instanceId,
+      label: option.instanceLabel,
+      featureCode: option.featureCode,
+      mandateId: option.mandateId,
+    };
+  }, [combinedOptions, selectedCombinedKey, instances]);
 
-  if (error && !selectedMandateId) {
+  // Get selected combined option for display
+  const selectedOption = useMemo(() => {
+    return combinedOptions.find(o => o.combinedKey === selectedCombinedKey);
+  }, [combinedOptions, selectedCombinedKey]);
+
+  if (error && !selectedCombinedKey) {
     return (
       <div className={styles.adminPage}>
         <div className={styles.errorContainer}>
@@ -344,50 +397,44 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
         </div>
       </div>
 
-      {/* Selectors */}
+      {/* Combined Selector: Mandate + Feature Instance */}
       <div className={styles.filterSection}>
-        <div className={styles.filterGroup}>
+        <div className={styles.filterGroup} style={{ flex: 1, maxWidth: 500 }}>
           <label className={styles.filterLabel}>
-            <FaBuilding style={{ marginRight: 8 }} />
-            Mandant:
+            <FaCube style={{ marginRight: 8 }} />
+            Mandant / Feature-Instanz:
           </label>
           <select
             className={styles.filterSelect}
-            value={selectedMandateId}
-            onChange={(e) => setSelectedMandateId(e.target.value)}
+            value={selectedCombinedKey}
+            onChange={(e) => setSelectedCombinedKey(e.target.value)}
+            disabled={loading || combinedOptions.length === 0}
           >
-            <option value="">-- Mandant wählen --</option>
-            {mandates.map(m => (
-              <option key={m.id} value={m.id}>
-                {getMandateName(m)}
-              </option>
-            ))}
+            <option value="">-- Mandant / Feature-Instanz wählen --</option>
+            {/* Group options by mandate */}
+            {(() => {
+              const groupedByMandate: Record<string, CombinedInstanceOption[]> = {};
+              combinedOptions.forEach(opt => {
+                if (!groupedByMandate[opt.mandateName]) {
+                  groupedByMandate[opt.mandateName] = [];
+                }
+                groupedByMandate[opt.mandateName].push(opt);
+              });
+              
+              return Object.entries(groupedByMandate).map(([mandateName, options]) => (
+                <optgroup key={mandateName} label={mandateName}>
+                  {options.map(opt => (
+                    <option key={opt.combinedKey} value={opt.combinedKey}>
+                      {opt.instanceLabel} ({getFeatureLabel(opt.featureCode)})
+                    </option>
+                  ))}
+                </optgroup>
+              ));
+            })()}
           </select>
         </div>
-
-        {selectedMandateId && (
-          <div className={styles.filterGroup}>
-            <label className={styles.filterLabel}>
-              <FaCube style={{ marginRight: 8 }} />
-              Feature-Instanz:
-            </label>
-            <select
-              className={styles.filterSelect}
-              value={selectedInstanceId}
-              onChange={(e) => setSelectedInstanceId(e.target.value)}
-              disabled={loading || instances.length === 0}
-            >
-              <option value="">-- Instanz wählen --</option>
-              {instances.map(i => (
-                <option key={i.id} value={i.id}>
-                  {i.label} ({getFeatureLabel(i.featureCode)})
-                </option>
-              ))}
-            </select>
-          </div>
-        )}
         
-        {selectedInstanceId && (
+        {selectedCombinedKey && (
           <div className={styles.headerActions}>
             <button
               className={styles.secondaryButton}
@@ -408,9 +455,19 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
       </div>
 
       {/* Info box when instance is selected */}
+      {selectedOption && (
+        <div className={styles.infoBox}>
+          <FaBuilding style={{ marginRight: 8 }} />
+          <span>Mandant: <strong>{selectedOption.mandateName}</strong></span>
+          <span style={{ margin: '0 16px', color: 'var(--color-border)' }}>|</span>
+          <FaCube style={{ marginRight: 8 }} />
+          <span>Instanz: <strong>{selectedOption.instanceLabel}</strong> ({selectedOption.featureCode})</span>
+        </div>
+      )}
+      
+      {/* Roles info box */}
       {selectedInstance && instanceRoles.length > 0 && (
         <div className={styles.infoBox}>
-          <FaCube style={{ marginRight: 8 }} />
           <span>Verfügbare Rollen: </span>
           {instanceRoles.map((r, i) => (
             <span key={r.id}>
@@ -430,21 +487,13 @@ export const AdminFeatureInstanceUsersPage: React.FC = () => {
       )}
 
       {/* Content */}
-      {!selectedMandateId ? (
-        <div className={styles.emptyState}>
-          <FaBuilding className={styles.emptyIcon} />
-          <h3 className={styles.emptyTitle}>Kein Mandant ausgewählt</h3>
-          <p className={styles.emptyDescription}>
-            Wählen Sie einen Mandanten aus, um dessen Feature-Instanzen zu sehen.
-          </p>
-        </div>
-      ) : !selectedInstanceId ? (
+      {!selectedCombinedKey ? (
         <div className={styles.emptyState}>
           <FaCube className={styles.emptyIcon} />
           <h3 className={styles.emptyTitle}>Keine Feature-Instanz ausgewählt</h3>
           <p className={styles.emptyDescription}>
-            {instances.length === 0 
-              ? 'Dieser Mandant hat noch keine Feature-Instanzen.' 
+            {combinedOptions.length === 0 
+              ? 'Es gibt noch keine Feature-Instanzen. Erstellen Sie zuerst Feature-Instanzen unter "Feature-Instanzen".' 
               : 'Wählen Sie eine Feature-Instanz aus, um deren Benutzer zu verwalten.'}
           </p>
         </div>
diff --git a/src/pages/admin/AdminFeatureRolesPage.tsx b/src/pages/admin/AdminFeatureRolesPage.tsx
index 3bfa17f..c72fb28 100644
--- a/src/pages/admin/AdminFeatureRolesPage.tsx
+++ b/src/pages/admin/AdminFeatureRolesPage.tsx
@@ -18,10 +18,13 @@ import api from '../../api';
 import styles from './Admin.module.css';
 
 interface Feature {
-  id: string;
-  featureCode: string;
-  name: string | { [key: string]: string };
+  id?: string;
+  code: string;  // Backend uses 'code' not 'featureCode'
+  featureCode?: string;  // Alias for backward compatibility
+  label: string | { [key: string]: string };  // Backend uses 'label' not 'name'
+  name?: string | { [key: string]: string };  // Alias for backward compatibility
   description?: string | { [key: string]: string };
+  icon?: string;
 }
 
 interface FeatureRole {
@@ -49,13 +52,13 @@ export const AdminFeatureRolesPage: React.FC = () => {
   useEffect(() => {
     const loadFeatures = async () => {
       try {
-        const response = await api.get('/api/features');
+        const response = await api.get('/api/features/');
         const featureList = response.data?.items || response.data || [];
         setFeatures(Array.isArray(featureList) ? featureList : []);
         
         // Auto-select first feature if available
         if (featureList.length > 0 && !selectedFeatureCode) {
-          setSelectedFeatureCode(featureList[0].featureCode);
+          setSelectedFeatureCode(featureList[0].code || featureList[0].featureCode || '');
         }
       } catch (err: any) {
         console.error('Error loading features:', err);
@@ -235,8 +238,8 @@ export const AdminFeatureRolesPage: React.FC = () => {
     setEditingRole(role);
   };
 
-  // Get feature name
-  const getFeatureName = (feature: Feature) => getTextValue(feature.name);
+  // Get feature name - Backend uses 'label' field
+  const getFeatureName = (feature: Feature) => getTextValue(feature.label || feature.name);
 
   if (error && !selectedFeatureCode) {
     return (
@@ -274,11 +277,14 @@ export const AdminFeatureRolesPage: React.FC = () => {
             onChange={(e) => setSelectedFeatureCode(e.target.value)}
           >
             <option value="">-- Feature wählen --</option>
-            {features.map(f => (
-              <option key={f.id} value={f.featureCode}>
-                {getFeatureName(f)} ({f.featureCode})
-              </option>
-            ))}
+            {features.map(f => {
+              const featureCode = f.code || f.featureCode || '';
+              return (
+                <option key={featureCode} value={featureCode}>
+                  {getFeatureName(f)} ({featureCode})
+                </option>
+              );
+            })}
           </select>
         </div>