diff --git a/modules/routes/routeDataMandates.py b/modules/routes/routeDataMandates.py
index ec109c6b..90948b8a 100644
--- a/modules/routes/routeDataMandates.py
+++ b/modules/routes/routeDataMandates.py
@@ -43,7 +43,7 @@ class UserMandateCreate(BaseModel):
 
 class UserMandateResponse(BaseModel):
     """Response model for user mandate membership"""
-    userMandateId: str
+    id: str  # UserMandate ID as primary key
     userId: str
     mandateId: str
     roleIds: List[str]
@@ -52,11 +52,11 @@ class UserMandateResponse(BaseModel):
 
 class MandateUserInfo(BaseModel):
     """User info within a mandate context"""
+    id: str  # UserMandate ID as primary key
     userId: str
     username: str
     email: Optional[str]
     fullName: Optional[str]
-    userMandateId: str
     roleIds: List[str]
     roleLabels: List[str]  # Resolved role labels for display
     enabled: bool
@@ -379,11 +379,11 @@ async def listMandateUsers(
                     roleLabels.append(roleId)  # Fallback to ID if not found
             
             result.append(MandateUserInfo(
+                id=um.get("id"),  # UserMandate ID as primary key
                 userId=str(user.id),
                 username=user.username,
                 email=user.email,
                 fullName=user.fullName,
-                userMandateId=um.get("id"),
                 roleIds=roleIds,
                 roleLabels=roleLabels,
                 enabled=um.get("enabled", True)
@@ -500,7 +500,7 @@ async def addUserToMandate(
         )
         
         return UserMandateResponse(
-            userMandateId=str(userMandate.id),
+            id=str(userMandate.id),  # UserMandate ID as primary key
             userId=data.targetUserId,
             mandateId=targetMandateId,
             roleIds=data.roleIds,
@@ -690,7 +690,7 @@ async def updateUserRolesInMandate(
         )
         
         return UserMandateResponse(
-            userMandateId=str(membership.id),
+            id=str(membership.id),  # UserMandate ID as primary key
             userId=targetUserId,
             mandateId=targetMandateId,
             roleIds=roleIds,
diff --git a/modules/routes/routeFeatures.py b/modules/routes/routeFeatures.py
index a9a124a8..43d120f1 100644
--- a/modules/routes/routeFeatures.py
+++ b/modules/routes/routeFeatures.py
@@ -722,11 +722,11 @@ class FeatureInstanceUserCreate(BaseModel):
 
 class FeatureInstanceUserResponse(BaseModel):
     """Response model for a user in a feature instance"""
+    id: str  # Use the FeatureAccess ID as primary key
     userId: str
     username: str
     email: Optional[str]
     fullName: Optional[str]
-    featureAccessId: str
     roleIds: List[str]
     roleLabels: List[str]
     enabled: bool
@@ -803,11 +803,11 @@ async def listFeatureInstanceUsers(
                     roleLabels.append(roles[0].get("roleLabel", ""))
             
             result.append(FeatureInstanceUserResponse(
+                id=featureAccessId,  # FeatureAccess ID as primary key
                 userId=userId,
                 username=user.get("username", ""),
                 email=user.get("email"),
                 fullName=user.get("fullName"),
-                featureAccessId=featureAccessId,
                 roleIds=roleIds,
                 roleLabels=roleLabels,
                 enabled=fa.get("enabled", True)