diff --git a/backend/src/core/middleware/require-tier.test.ts b/backend/src/core/middleware/require-tier.test.ts
index 13fc80f..cdd32cf 100644
--- a/backend/src/core/middleware/require-tier.test.ts
+++ b/backend/src/core/middleware/require-tier.test.ts
@@ -17,7 +17,7 @@ const createRequest = (subscriptionTier?: string): Partial<FastifyRequest> => {
   }
   return {
     userContext: {
-      userId: 'auth0|user123456789',
+      userId: '550e8400-e29b-41d4-a716-446655440000',
       email: 'user@example.com',
       emailVerified: true,
       onboardingCompleted: true,
diff --git a/backend/src/core/plugins/tests/tier-guard.plugin.test.ts b/backend/src/core/plugins/tests/tier-guard.plugin.test.ts
index de24c75..f7a754b 100644
--- a/backend/src/core/plugins/tests/tier-guard.plugin.test.ts
+++ b/backend/src/core/plugins/tests/tier-guard.plugin.test.ts
@@ -26,7 +26,7 @@ describe('tier guard plugin', () => {
     // Mock authenticate to set userContext
     authenticateMock = jest.fn(async (request: FastifyRequest) => {
       request.userContext = {
-        userId: 'auth0|user123',
+        userId: '550e8400-e29b-41d4-a716-446655440000',
         email: 'user@example.com',
         emailVerified: true,
         onboardingCompleted: true,
@@ -48,7 +48,7 @@ describe('tier guard plugin', () => {
     it('allows access when user tier meets minimum', async () => {
       authenticateMock.mockImplementation(async (request: FastifyRequest) => {
         request.userContext = {
-          userId: 'auth0|user123',
+          userId: '550e8400-e29b-41d4-a716-446655440000',
           email: 'user@example.com',
           emailVerified: true,
           onboardingCompleted: true,
@@ -71,7 +71,7 @@ describe('tier guard plugin', () => {
     it('allows access when user tier exceeds minimum', async () => {
       authenticateMock.mockImplementation(async (request: FastifyRequest) => {
         request.userContext = {
-          userId: 'auth0|user123',
+          userId: '550e8400-e29b-41d4-a716-446655440000',
           email: 'user@example.com',
           emailVerified: true,
           onboardingCompleted: true,
@@ -130,7 +130,7 @@ describe('tier guard plugin', () => {
     it('allows pro tier access to pro feature', async () => {
       authenticateMock.mockImplementation(async (request: FastifyRequest) => {
         request.userContext = {
-          userId: 'auth0|user123',
+          userId: '550e8400-e29b-41d4-a716-446655440000',
           email: 'user@example.com',
           emailVerified: true,
           onboardingCompleted: true,
diff --git a/backend/src/features/admin/tests/integration/admin.integration.test.ts b/backend/src/features/admin/tests/integration/admin.integration.test.ts
index 377619d..a7e03bf 100644
--- a/backend/src/features/admin/tests/integration/admin.integration.test.ts
+++ b/backend/src/features/admin/tests/integration/admin.integration.test.ts
@@ -4,18 +4,19 @@
  */
 
 import request from 'supertest';
-import { app } from '../../../../app';
+import { buildApp } from '../../../../app';
 import pool from '../../../../core/config/database';
+import { FastifyInstance } from 'fastify';
 import { readFileSync } from 'fs';
 import { join } from 'path';
 import fastifyPlugin from 'fastify-plugin';
 import { setAdminGuardPool } from '../../../../core/plugins/admin-guard.plugin';
 
-const DEFAULT_ADMIN_SUB = 'test-admin-123';
+const DEFAULT_ADMIN_ID = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
 const DEFAULT_ADMIN_EMAIL = 'test-admin@motovaultpro.com';
 
 let currentUser = {
-  sub: DEFAULT_ADMIN_SUB,
+  sub: 'auth0|test-admin-123',
   email: DEFAULT_ADMIN_EMAIL,
 };
 
@@ -25,11 +26,15 @@ jest.mock('../../../../core/plugins/auth.plugin', () => {
     default: fastifyPlugin(async function(fastify) {
       fastify.decorate('authenticate', async function(request, _reply) {
         // Inject dynamic test user context
+        // JWT sub is still auth0|xxx format
         request.user = { sub: currentUser.sub };
         request.userContext = {
-          userId: currentUser.sub,
+          userId: DEFAULT_ADMIN_ID,
           email: currentUser.email,
+          emailVerified: true,
+          onboardingCompleted: true,
           isAdmin: false, // Will be set by admin guard
+          subscriptionTier: 'free',
         };
       });
     }, { name: 'auth-plugin' })
@@ -37,10 +42,14 @@ jest.mock('../../../../core/plugins/auth.plugin', () => {
 });
 
 describe('Admin Management Integration Tests', () => {
-  let testAdminAuth0Sub: string;
-  let testNonAdminAuth0Sub: string;
+  let app: FastifyInstance;
+  let testAdminId: string;
 
   beforeAll(async () => {
+    // Build the app
+    app = await buildApp();
+    await app.ready();
+
     // Run the admin migration directly using the migration file
     const migrationFile = join(__dirname, '../../migrations/001_create_admin_users.sql');
     const migrationSQL = readFileSync(migrationFile, 'utf-8');
@@ -50,33 +59,31 @@ describe('Admin Management Integration Tests', () => {
     setAdminGuardPool(pool);
 
     // Create test admin user
-    testAdminAuth0Sub = DEFAULT_ADMIN_SUB;
+    testAdminId = DEFAULT_ADMIN_ID;
     await pool.query(`
-      INSERT INTO admin_users (auth0_sub, email, role, created_by)
-      VALUES ($1, $2, $3, $4)
-      ON CONFLICT (auth0_sub) DO NOTHING
-    `, [testAdminAuth0Sub, DEFAULT_ADMIN_EMAIL, 'admin', 'system']);
-
-    // Create test non-admin auth0Sub for permission tests
-    testNonAdminAuth0Sub = 'test-non-admin-456';
+      INSERT INTO admin_users (id, user_profile_id, email, role, created_by)
+      VALUES ($1, $2, $3, $4, $5)
+      ON CONFLICT (user_profile_id) DO NOTHING
+    `, [testAdminId, testAdminId, DEFAULT_ADMIN_EMAIL, 'admin', 'system']);
   });
 
   afterAll(async () => {
     // Clean up test database
     await pool.query('DROP TABLE IF EXISTS admin_audit_logs CASCADE');
     await pool.query('DROP TABLE IF EXISTS admin_users CASCADE');
+    await app.close();
     await pool.end();
   });
 
   beforeEach(async () => {
     // Clean up test data before each test (except the test admin)
     await pool.query(
-      'DELETE FROM admin_users WHERE auth0_sub != $1 AND auth0_sub != $2',
-      [testAdminAuth0Sub, 'system|bootstrap']
+      'DELETE FROM admin_users WHERE user_profile_id != $1',
+      [testAdminId]
     );
     await pool.query('DELETE FROM admin_audit_logs');
     currentUser = {
-      sub: DEFAULT_ADMIN_SUB,
+      sub: 'auth0|test-admin-123',
       email: DEFAULT_ADMIN_EMAIL,
     };
   });
@@ -85,11 +92,11 @@ describe('Admin Management Integration Tests', () => {
     it('should reject non-admin user trying to list admins', async () => {
       // Create mock for non-admin user
       currentUser = {
-        sub: testNonAdminAuth0Sub,
+        sub: 'auth0|test-non-admin-456',
         email: 'test-user@example.com',
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/admins')
         .expect(403);
 
@@ -101,51 +108,51 @@ describe('Admin Management Integration Tests', () => {
   describe('GET /api/admin/verify', () => {
     it('should confirm admin access for existing admin', async () => {
       currentUser = {
-        sub: testAdminAuth0Sub,
+        sub: 'auth0|test-admin-123',
         email: DEFAULT_ADMIN_EMAIL,
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/verify')
         .expect(200);
 
       expect(response.body.isAdmin).toBe(true);
       expect(response.body.adminRecord).toMatchObject({
-        auth0Sub: testAdminAuth0Sub,
+        id: testAdminId,
         email: DEFAULT_ADMIN_EMAIL,
       });
     });
 
-    it('should link admin record by email when auth0_sub differs', async () => {
-      const placeholderSub = 'auth0|placeholder-sub';
-      const realSub = 'auth0|real-admin-sub';
+    it('should link admin record by email when user_profile_id differs', async () => {
+      const placeholderId = '9b9a1234-1234-1234-1234-123456789abc';
+      const realId = 'a1b2c3d4-5678-90ab-cdef-123456789def';
       const email = 'link-admin@example.com';
 
       await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by)
-        VALUES ($1, $2, $3, $4)
-      `, [placeholderSub, email, 'admin', testAdminAuth0Sub]);
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by)
+        VALUES ($1, $2, $3, $4, $5)
+      `, [placeholderId, placeholderId, email, 'admin', testAdminId]);
 
       currentUser = {
-        sub: realSub,
+        sub: 'auth0|real-admin-sub',
         email,
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/verify')
         .expect(200);
 
       expect(response.body.isAdmin).toBe(true);
       expect(response.body.adminRecord).toMatchObject({
-        auth0Sub: realSub,
+        userProfileId: realId,
         email,
       });
 
       const record = await pool.query(
-        'SELECT auth0_sub FROM admin_users WHERE email = $1',
+        'SELECT user_profile_id FROM admin_users WHERE email = $1',
         [email]
       );
-      expect(record.rows[0].auth0_sub).toBe(realSub);
+      expect(record.rows[0].user_profile_id).toBe(realId);
     });
 
     it('should return non-admin response for unknown user', async () => {
@@ -154,7 +161,7 @@ describe('Admin Management Integration Tests', () => {
         email: 'non-admin@example.com',
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/verify')
         .expect(200);
 
@@ -166,17 +173,19 @@ describe('Admin Management Integration Tests', () => {
   describe('GET /api/admin/admins', () => {
     it('should list all admin users', async () => {
       // Create additional test admins
+      const admin1Id = '6ba7b810-9dad-11d1-80b4-00c04fd430c8';
+      const admin2Id = '8f14e45f-ceea-367f-a27f-c9a6d0c67e0e';
       await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by)
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by)
         VALUES
-        ($1, $2, $3, $4),
-        ($5, $6, $7, $8)
+        ($1, $2, $3, $4, $5),
+        ($6, $7, $8, $9, $10)
       `, [
-        'auth0|admin1', 'admin1@example.com', 'admin', testAdminAuth0Sub,
-        'auth0|admin2', 'admin2@example.com', 'super_admin', testAdminAuth0Sub
+        admin1Id, admin1Id, 'admin1@example.com', 'admin', testAdminId,
+        admin2Id, admin2Id, 'admin2@example.com', 'super_admin', testAdminId
       ]);
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/admins')
         .expect(200);
 
@@ -184,7 +193,7 @@ describe('Admin Management Integration Tests', () => {
       expect(response.body).toHaveProperty('admins');
       expect(response.body.admins.length).toBeGreaterThanOrEqual(3); // At least test admin + 2 created
       expect(response.body.admins[0]).toMatchObject({
-        auth0Sub: expect.any(String),
+        id: expect.any(String),
         email: expect.any(String),
         role: expect.stringMatching(/^(admin|super_admin)$/),
         createdAt: expect.any(String),
@@ -194,12 +203,13 @@ describe('Admin Management Integration Tests', () => {
 
     it('should include revoked admins in the list', async () => {
       // Create and revoke an admin
+      const revokedId = 'f1e2d3c4-b5a6-9788-6543-210fedcba987';
       await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by, revoked_at)
-        VALUES ($1, $2, $3, $4, CURRENT_TIMESTAMP)
-      `, ['auth0|revoked', 'revoked@example.com', 'admin', testAdminAuth0Sub]);
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by, revoked_at)
+        VALUES ($1, $2, $3, $4, $5, CURRENT_TIMESTAMP)
+      `, [revokedId, revokedId, 'revoked@example.com', 'admin', testAdminId]);
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/admins')
         .expect(200);
 
@@ -218,17 +228,17 @@ describe('Admin Management Integration Tests', () => {
         role: 'admin'
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .post('/api/admin/admins')
         .send(newAdminData)
         .expect(201);
 
       expect(response.body).toMatchObject({
-        auth0Sub: expect.any(String),
+        id: expect.any(String),
         email: 'newadmin@example.com',
         role: 'admin',
         createdAt: expect.any(String),
-        createdBy: testAdminAuth0Sub,
+        createdBy: testAdminId,
         revokedAt: null
       });
 
@@ -238,7 +248,7 @@ describe('Admin Management Integration Tests', () => {
         ['CREATE', 'newadmin@example.com']
       );
       expect(auditResult.rows.length).toBe(1);
-      expect(auditResult.rows[0].actor_admin_id).toBe(testAdminAuth0Sub);
+      expect(auditResult.rows[0].actor_admin_id).toBe(testAdminId);
     });
 
     it('should reject invalid email', async () => {
@@ -247,7 +257,7 @@ describe('Admin Management Integration Tests', () => {
         role: 'admin'
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .post('/api/admin/admins')
         .send(invalidData)
         .expect(400);
@@ -263,13 +273,13 @@ describe('Admin Management Integration Tests', () => {
       };
 
       // Create first admin
-      await request(app)
+      await request(app.server)
         .post('/api/admin/admins')
         .send(adminData)
         .expect(201);
 
       // Try to create duplicate
-      const response = await request(app)
+      const response = await request(app.server)
         .post('/api/admin/admins')
         .send(adminData)
         .expect(400);
@@ -284,7 +294,7 @@ describe('Admin Management Integration Tests', () => {
         role: 'super_admin'
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .post('/api/admin/admins')
         .send(superAdminData)
         .expect(201);
@@ -297,7 +307,7 @@ describe('Admin Management Integration Tests', () => {
         email: 'defaultrole@example.com'
       };
 
-      const response = await request(app)
+      const response = await request(app.server)
         .post('/api/admin/admins')
         .send(adminData)
         .expect(201);
@@ -306,23 +316,24 @@ describe('Admin Management Integration Tests', () => {
     });
   });
 
-  describe('PATCH /api/admin/admins/:auth0Sub/revoke', () => {
+  describe('PATCH /api/admin/admins/:id/revoke', () => {
     it('should revoke admin access', async () => {
       // Create admin to revoke
+      const toRevokeId = 'b1c2d3e4-f5a6-7890-1234-567890abcdef';
       const createResult = await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by)
-        VALUES ($1, $2, $3, $4)
-        RETURNING auth0_sub
-      `, ['auth0|to-revoke', 'torevoke@example.com', 'admin', testAdminAuth0Sub]);
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by)
+        VALUES ($1, $2, $3, $4, $5)
+        RETURNING id
+      `, [toRevokeId, toRevokeId, 'torevoke@example.com', 'admin', testAdminId]);
 
-      const auth0Sub = createResult.rows[0].auth0_sub;
+      const adminId = createResult.rows[0].id;
 
-      const response = await request(app)
-        .patch(`/api/admin/admins/${auth0Sub}/revoke`)
+      const response = await request(app.server)
+        .patch(`/api/admin/admins/${adminId}/revoke`)
         .expect(200);
 
       expect(response.body).toMatchObject({
-        auth0Sub,
+        id: adminId,
         email: 'torevoke@example.com',
         revokedAt: expect.any(String)
       });
@@ -330,7 +341,7 @@ describe('Admin Management Integration Tests', () => {
       // Verify audit log
       const auditResult = await pool.query(
         'SELECT * FROM admin_audit_logs WHERE action = $1 AND target_admin_id = $2',
-        ['REVOKE', auth0Sub]
+        ['REVOKE', adminId]
       );
       expect(auditResult.rows.length).toBe(1);
     });
@@ -338,12 +349,12 @@ describe('Admin Management Integration Tests', () => {
     it('should prevent revoking last active admin', async () => {
       // First, ensure only one active admin exists
       await pool.query(
-        'UPDATE admin_users SET revoked_at = CURRENT_TIMESTAMP WHERE auth0_sub != $1',
-        [testAdminAuth0Sub]
+        'UPDATE admin_users SET revoked_at = CURRENT_TIMESTAMP WHERE user_profile_id != $1',
+        [testAdminId]
       );
 
-      const response = await request(app)
-        .patch(`/api/admin/admins/${testAdminAuth0Sub}/revoke`)
+      const response = await request(app.server)
+        .patch(`/api/admin/admins/${testAdminId}/revoke`)
         .expect(400);
 
       expect(response.body.error).toBe('Bad Request');
@@ -351,8 +362,8 @@ describe('Admin Management Integration Tests', () => {
     });
 
     it('should return 404 for non-existent admin', async () => {
-      const response = await request(app)
-        .patch('/api/admin/admins/auth0|nonexistent/revoke')
+      const response = await request(app.server)
+        .patch('/api/admin/admins/00000000-0000-0000-0000-000000000000/revoke')
         .expect(404);
 
       expect(response.body.error).toBe('Not Found');
@@ -360,23 +371,24 @@ describe('Admin Management Integration Tests', () => {
     });
   });
 
-  describe('PATCH /api/admin/admins/:auth0Sub/reinstate', () => {
+  describe('PATCH /api/admin/admins/:id/reinstate', () => {
     it('should reinstate revoked admin', async () => {
       // Create revoked admin
+      const reinstateId = 'c2d3e4f5-a6b7-8901-2345-678901bcdef0';
       const createResult = await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by, revoked_at)
-        VALUES ($1, $2, $3, $4, CURRENT_TIMESTAMP)
-        RETURNING auth0_sub
-      `, ['auth0|to-reinstate', 'toreinstate@example.com', 'admin', testAdminAuth0Sub]);
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by, revoked_at)
+        VALUES ($1, $2, $3, $4, $5, CURRENT_TIMESTAMP)
+        RETURNING id
+      `, [reinstateId, reinstateId, 'toreinstate@example.com', 'admin', testAdminId]);
 
-      const auth0Sub = createResult.rows[0].auth0_sub;
+      const adminId = createResult.rows[0].id;
 
-      const response = await request(app)
-        .patch(`/api/admin/admins/${auth0Sub}/reinstate`)
+      const response = await request(app.server)
+        .patch(`/api/admin/admins/${adminId}/reinstate`)
         .expect(200);
 
       expect(response.body).toMatchObject({
-        auth0Sub,
+        id: adminId,
         email: 'toreinstate@example.com',
         revokedAt: null
       });
@@ -384,14 +396,14 @@ describe('Admin Management Integration Tests', () => {
       // Verify audit log
       const auditResult = await pool.query(
         'SELECT * FROM admin_audit_logs WHERE action = $1 AND target_admin_id = $2',
-        ['REINSTATE', auth0Sub]
+        ['REINSTATE', adminId]
       );
       expect(auditResult.rows.length).toBe(1);
     });
 
     it('should return 404 for non-existent admin', async () => {
-      const response = await request(app)
-        .patch('/api/admin/admins/auth0|nonexistent/reinstate')
+      const response = await request(app.server)
+        .patch('/api/admin/admins/00000000-0000-0000-0000-000000000000/reinstate')
         .expect(404);
 
       expect(response.body.error).toBe('Not Found');
@@ -400,16 +412,17 @@ describe('Admin Management Integration Tests', () => {
 
     it('should handle reinstating already active admin', async () => {
       // Create active admin
+      const activeId = 'd3e4f5a6-b7c8-9012-3456-789012cdef01';
       const createResult = await pool.query(`
-        INSERT INTO admin_users (auth0_sub, email, role, created_by)
-        VALUES ($1, $2, $3, $4)
-        RETURNING auth0_sub
-      `, ['auth0|already-active', 'active@example.com', 'admin', testAdminAuth0Sub]);
+        INSERT INTO admin_users (id, user_profile_id, email, role, created_by)
+        VALUES ($1, $2, $3, $4, $5)
+        RETURNING id
+      `, [activeId, activeId, 'active@example.com', 'admin', testAdminId]);
 
-      const auth0Sub = createResult.rows[0].auth0_sub;
+      const adminId = createResult.rows[0].id;
 
-      const response = await request(app)
-        .patch(`/api/admin/admins/${auth0Sub}/reinstate`)
+      const response = await request(app.server)
+        .patch(`/api/admin/admins/${adminId}/reinstate`)
         .expect(200);
 
       expect(response.body.revokedAt).toBeNull();
@@ -426,12 +439,12 @@ describe('Admin Management Integration Tests', () => {
         ($5, $6, $7, $8),
         ($9, $10, $11, $12)
       `, [
-        testAdminAuth0Sub, 'CREATE', 'admin_user', 'test1@example.com',
-        testAdminAuth0Sub, 'REVOKE', 'admin_user', 'test2@example.com',
-        testAdminAuth0Sub, 'REINSTATE', 'admin_user', 'test3@example.com'
+        testAdminId, 'CREATE', 'admin_user', 'test1@example.com',
+        testAdminId, 'REVOKE', 'admin_user', 'test2@example.com',
+        testAdminId, 'REINSTATE', 'admin_user', 'test3@example.com'
       ]);
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/audit-logs')
         .expect(200);
 
@@ -440,7 +453,7 @@ describe('Admin Management Integration Tests', () => {
       expect(response.body.logs.length).toBeGreaterThanOrEqual(3);
       expect(response.body.logs[0]).toMatchObject({
         id: expect.any(String),
-        actorAdminId: testAdminAuth0Sub,
+        actorAdminId: testAdminId,
         action: expect.any(String),
         resourceType: expect.any(String),
         createdAt: expect.any(String)
@@ -453,10 +466,10 @@ describe('Admin Management Integration Tests', () => {
         await pool.query(`
           INSERT INTO admin_audit_logs (actor_admin_id, action, resource_type, resource_id)
           VALUES ($1, $2, $3, $4)
-        `, [testAdminAuth0Sub, 'CREATE', 'admin_user', `test${i}@example.com`]);
+        `, [testAdminId, 'CREATE', 'admin_user', `test${i}@example.com`]);
       }
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/audit-logs?limit=5&offset=0')
         .expect(200);
 
@@ -473,12 +486,12 @@ describe('Admin Management Integration Tests', () => {
         ($3, $4, CURRENT_TIMESTAMP - INTERVAL '1 minute'),
         ($5, $6, CURRENT_TIMESTAMP)
       `, [
-        testAdminAuth0Sub, 'FIRST',
-        testAdminAuth0Sub, 'SECOND',
-        testAdminAuth0Sub, 'THIRD'
+        testAdminId, 'FIRST',
+        testAdminId, 'SECOND',
+        testAdminId, 'THIRD'
       ]);
 
-      const response = await request(app)
+      const response = await request(app.server)
         .get('/api/admin/audit-logs?limit=3')
         .expect(200);
 
@@ -491,45 +504,45 @@ describe('Admin Management Integration Tests', () => {
   describe('End-to-end workflow', () => {
     it('should create, revoke, and reinstate admin with full audit trail', async () => {
       // 1. Create new admin
-      const createResponse = await request(app)
+      const createResponse = await request(app.server)
         .post('/api/admin/admins')
         .send({ email: 'workflow@example.com', role: 'admin' })
         .expect(201);
 
-      const auth0Sub = createResponse.body.auth0Sub;
+      const adminId = createResponse.body.id;
 
       // 2. Verify admin appears in list
-      const listResponse = await request(app)
+      const listResponse = await request(app.server)
         .get('/api/admin/admins')
         .expect(200);
 
       const createdAdmin = listResponse.body.admins.find(
-        (admin: any) => admin.auth0Sub === auth0Sub
+        (admin: any) => admin.id === adminId
       );
       expect(createdAdmin).toBeDefined();
       expect(createdAdmin.revokedAt).toBeNull();
 
       // 3. Revoke admin
-      const revokeResponse = await request(app)
-        .patch(`/api/admin/admins/${auth0Sub}/revoke`)
+      const revokeResponse = await request(app.server)
+        .patch(`/api/admin/admins/${adminId}/revoke`)
         .expect(200);
 
       expect(revokeResponse.body.revokedAt).toBeTruthy();
 
       // 4. Reinstate admin
-      const reinstateResponse = await request(app)
-        .patch(`/api/admin/admins/${auth0Sub}/reinstate`)
+      const reinstateResponse = await request(app.server)
+        .patch(`/api/admin/admins/${adminId}/reinstate`)
         .expect(200);
 
       expect(reinstateResponse.body.revokedAt).toBeNull();
 
       // 5. Verify complete audit trail
-      const auditResponse = await request(app)
+      const auditResponse = await request(app.server)
         .get('/api/admin/audit-logs')
         .expect(200);
 
       const workflowLogs = auditResponse.body.logs.filter(
-        (log: any) => log.targetAdminId === auth0Sub || log.resourceId === 'workflow@example.com'
+        (log: any) => log.targetAdminId === adminId || log.resourceId === 'workflow@example.com'
       );
 
       expect(workflowLogs.length).toBeGreaterThanOrEqual(3);
diff --git a/backend/src/features/admin/tests/unit/admin.guard.test.ts b/backend/src/features/admin/tests/unit/admin.guard.test.ts
index e2a281e..6cf3887 100644
--- a/backend/src/features/admin/tests/unit/admin.guard.test.ts
+++ b/backend/src/features/admin/tests/unit/admin.guard.test.ts
@@ -26,7 +26,7 @@ describe('admin guard plugin', () => {
     fastify = Fastify();
     authenticateMock = jest.fn(async (request: FastifyRequest) => {
       request.userContext = {
-        userId: 'auth0|admin',
+        userId: '7c9e6679-7425-40de-944b-e07fc1f90ae7',
         email: 'admin@motovaultpro.com',
         emailVerified: true,
         onboardingCompleted: true,
@@ -41,7 +41,7 @@ describe('admin guard plugin', () => {
     mockPool = {
       query: jest.fn().mockResolvedValue({
         rows: [{
-          auth0_sub: 'auth0|admin',
+          user_profile_id: '7c9e6679-7425-40de-944b-e07fc1f90ae7',
           email: 'admin@motovaultpro.com',
           role: 'admin',
           revoked_at: null,
diff --git a/backend/src/features/admin/tests/unit/admin.service.test.ts b/backend/src/features/admin/tests/unit/admin.service.test.ts
index b1d7aaa..6dfda6a 100644
--- a/backend/src/features/admin/tests/unit/admin.service.test.ts
+++ b/backend/src/features/admin/tests/unit/admin.service.test.ts
@@ -6,13 +6,23 @@
 import { AdminService } from '../../domain/admin.service';
 import { AdminRepository } from '../../data/admin.repository';
 
+// Mock the audit log service
+jest.mock('../../../audit-log', () => ({
+  auditLogService: {
+    info: jest.fn().mockResolvedValue(undefined),
+    warn: jest.fn().mockResolvedValue(undefined),
+    error: jest.fn().mockResolvedValue(undefined),
+  },
+}));
+
 describe('AdminService', () => {
   let adminService: AdminService;
   let mockRepository: jest.Mocked<AdminRepository>;
 
   beforeEach(() => {
     mockRepository = {
-      getAdminByAuth0Sub: jest.fn(),
+      getAdminById: jest.fn(),
+      getAdminByUserProfileId: jest.fn(),
       getAdminByEmail: jest.fn(),
       getAllAdmins: jest.fn(),
       getActiveAdmins: jest.fn(),
@@ -26,30 +36,31 @@ describe('AdminService', () => {
     adminService = new AdminService(mockRepository);
   });
 
-  describe('getAdminByAuth0Sub', () => {
+  describe('getAdminById', () => {
     it('should return admin when found', async () => {
       const mockAdmin = {
-        auth0Sub: 'auth0|123456',
+        id: '7c9e6679-7425-40de-944b-e07fc1f90ae7',
+        userProfileId: '7c9e6679-7425-40de-944b-e07fc1f90ae7',
         email: 'admin@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'system',
+        createdBy: '550e8400-e29b-41d4-a716-446655440000',
         revokedAt: null,
         updatedAt: new Date(),
       };
 
-      mockRepository.getAdminByAuth0Sub.mockResolvedValue(mockAdmin);
+      mockRepository.getAdminById.mockResolvedValue(mockAdmin);
 
-      const result = await adminService.getAdminByAuth0Sub('auth0|123456');
+      const result = await adminService.getAdminById('7c9e6679-7425-40de-944b-e07fc1f90ae7');
 
       expect(result).toEqual(mockAdmin);
-      expect(mockRepository.getAdminByAuth0Sub).toHaveBeenCalledWith('auth0|123456');
+      expect(mockRepository.getAdminById).toHaveBeenCalledWith('7c9e6679-7425-40de-944b-e07fc1f90ae7');
     });
 
     it('should return null when admin not found', async () => {
-      mockRepository.getAdminByAuth0Sub.mockResolvedValue(null);
+      mockRepository.getAdminById.mockResolvedValue(null);
 
-      const result = await adminService.getAdminByAuth0Sub('auth0|unknown');
+      const result = await adminService.getAdminById('00000000-0000-0000-0000-000000000000');
 
       expect(result).toBeNull();
     });
@@ -57,12 +68,15 @@ describe('AdminService', () => {
 
   describe('createAdmin', () => {
     it('should create new admin and log audit', async () => {
+      const newAdminId = '8f14e45f-ceea-367f-a27f-c9a6d0c67e0e';
+      const creatorId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const mockAdmin = {
-        auth0Sub: 'auth0|newadmin',
+        id: newAdminId,
+        userProfileId: newAdminId,
         email: 'newadmin@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'auth0|existing',
+        createdBy: creatorId,
         revokedAt: null,
         updatedAt: new Date(),
       };
@@ -74,16 +88,16 @@ describe('AdminService', () => {
       const result = await adminService.createAdmin(
         'newadmin@motovaultpro.com',
         'admin',
-        'auth0|newadmin',
-        'auth0|existing'
+        newAdminId,
+        creatorId
       );
 
       expect(result).toEqual(mockAdmin);
       expect(mockRepository.createAdmin).toHaveBeenCalled();
       expect(mockRepository.logAuditAction).toHaveBeenCalledWith(
-        'auth0|existing',
+        creatorId,
         'CREATE',
-        mockAdmin.auth0Sub,
+        mockAdmin.id,
         'admin_user',
         mockAdmin.email,
         expect.any(Object)
@@ -91,12 +105,14 @@ describe('AdminService', () => {
     });
 
     it('should reject if admin already exists', async () => {
+      const existingId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const existingAdmin = {
-        auth0Sub: 'auth0|existing',
+        id: existingId,
+        userProfileId: existingId,
         email: 'admin@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'system',
+        createdBy: '550e8400-e29b-41d4-a716-446655440000',
         revokedAt: null,
         updatedAt: new Date(),
       };
@@ -104,39 +120,46 @@ describe('AdminService', () => {
       mockRepository.getAdminByEmail.mockResolvedValue(existingAdmin);
 
       await expect(
-        adminService.createAdmin('admin@motovaultpro.com', 'admin', 'auth0|new', 'auth0|existing')
+        adminService.createAdmin('admin@motovaultpro.com', 'admin', '8f14e45f-ceea-367f-a27f-c9a6d0c67e0e', existingId)
       ).rejects.toThrow('already exists');
     });
   });
 
   describe('revokeAdmin', () => {
     it('should revoke admin when multiple active admins exist', async () => {
+      const toRevokeId = 'a1b2c3d4-e5f6-7890-1234-567890abcdef';
+      const admin1Id = '6ba7b810-9dad-11d1-80b4-00c04fd430c8';
+      const admin2Id = '8f14e45f-ceea-367f-a27f-c9a6d0c67e0e';
+
       const revokedAdmin = {
-        auth0Sub: 'auth0|toadmin',
+        id: toRevokeId,
+        userProfileId: toRevokeId,
         email: 'toadmin@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'system',
+        createdBy: '550e8400-e29b-41d4-a716-446655440000',
         revokedAt: new Date(),
         updatedAt: new Date(),
       };
 
       const activeAdmins = [
         {
-          auth0Sub: 'auth0|admin1',
+          id: admin1Id,
+          userProfileId: admin1Id,
           email: 'admin1@motovaultpro.com',
-          role: 'admin',
+          role: 'admin' as const,
           createdAt: new Date(),
-          createdBy: 'system',
+          createdBy: '550e8400-e29b-41d4-a716-446655440000',
           revokedAt: null,
           updatedAt: new Date(),
         },
         {
-          auth0Sub: 'auth0|admin2',
+          id: admin2Id,
+          userProfileId: admin2Id,
           email: 'admin2@motovaultpro.com',
-          role: 'admin',
+          role: 'admin' as const,
           createdAt: new Date(),
-          createdBy: 'system',
+          createdBy: '550e8400-e29b-41d4-a716-446655440000',
           revokedAt: null,
           updatedAt: new Date(),
         },
@@ -146,20 +169,22 @@ describe('AdminService', () => {
       mockRepository.revokeAdmin.mockResolvedValue(revokedAdmin);
       mockRepository.logAuditAction.mockResolvedValue({} as any);
 
-      const result = await adminService.revokeAdmin('auth0|toadmin', 'auth0|admin1');
+      const result = await adminService.revokeAdmin(toRevokeId, admin1Id);
 
       expect(result).toEqual(revokedAdmin);
-      expect(mockRepository.revokeAdmin).toHaveBeenCalledWith('auth0|toadmin');
+      expect(mockRepository.revokeAdmin).toHaveBeenCalledWith(toRevokeId);
       expect(mockRepository.logAuditAction).toHaveBeenCalled();
     });
 
     it('should prevent revoking last active admin', async () => {
+      const lastAdminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const lastAdmin = {
-        auth0Sub: 'auth0|lastadmin',
+        id: lastAdminId,
+        userProfileId: lastAdminId,
         email: 'last@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'system',
+        createdBy: '550e8400-e29b-41d4-a716-446655440000',
         revokedAt: null,
         updatedAt: new Date(),
       };
@@ -167,19 +192,22 @@ describe('AdminService', () => {
       mockRepository.getActiveAdmins.mockResolvedValue([lastAdmin]);
 
       await expect(
-        adminService.revokeAdmin('auth0|lastadmin', 'auth0|lastadmin')
+        adminService.revokeAdmin(lastAdminId, lastAdminId)
       ).rejects.toThrow('Cannot revoke the last active admin');
     });
   });
 
   describe('reinstateAdmin', () => {
     it('should reinstate revoked admin and log audit', async () => {
+      const reinstateId = 'b2c3d4e5-f6a7-8901-2345-678901bcdef0';
+      const adminActorId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const reinstatedAdmin = {
-        auth0Sub: 'auth0|reinstate',
+        id: reinstateId,
+        userProfileId: reinstateId,
         email: 'reinstate@motovaultpro.com',
-        role: 'admin',
+        role: 'admin' as const,
         createdAt: new Date(),
-        createdBy: 'system',
+        createdBy: '550e8400-e29b-41d4-a716-446655440000',
         revokedAt: null,
         updatedAt: new Date(),
       };
@@ -187,14 +215,14 @@ describe('AdminService', () => {
       mockRepository.reinstateAdmin.mockResolvedValue(reinstatedAdmin);
       mockRepository.logAuditAction.mockResolvedValue({} as any);
 
-      const result = await adminService.reinstateAdmin('auth0|reinstate', 'auth0|admin');
+      const result = await adminService.reinstateAdmin(reinstateId, adminActorId);
 
       expect(result).toEqual(reinstatedAdmin);
-      expect(mockRepository.reinstateAdmin).toHaveBeenCalledWith('auth0|reinstate');
+      expect(mockRepository.reinstateAdmin).toHaveBeenCalledWith(reinstateId);
       expect(mockRepository.logAuditAction).toHaveBeenCalledWith(
-        'auth0|admin',
+        adminActorId,
         'REINSTATE',
-        'auth0|reinstate',
+        reinstateId,
         'admin_user',
         reinstatedAdmin.email
       );
diff --git a/backend/src/features/audit-log/__tests__/audit-log.integration.test.ts b/backend/src/features/audit-log/__tests__/audit-log.integration.test.ts
index 73b9a23..7b376aa 100644
--- a/backend/src/features/audit-log/__tests__/audit-log.integration.test.ts
+++ b/backend/src/features/audit-log/__tests__/audit-log.integration.test.ts
@@ -32,7 +32,7 @@ describe('AuditLog Feature Integration', () => {
 
   describe('Vehicle logging integration', () => {
     it('should create audit log with vehicle category and correct resource', async () => {
-      const userId = 'test-user-vehicle-123';
+      const userId = '550e8400-e29b-41d4-a716-446655440000';
       const vehicleId = 'vehicle-uuid-123';
       const entry = await service.info(
         'vehicle',
@@ -56,7 +56,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should log vehicle update with correct fields', async () => {
-      const userId = 'test-user-vehicle-456';
+      const userId = '6ba7b810-9dad-11d1-80b4-00c04fd430c8';
       const vehicleId = 'vehicle-uuid-456';
       const entry = await service.info(
         'vehicle',
@@ -75,7 +75,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should log vehicle deletion with vehicle info', async () => {
-      const userId = 'test-user-vehicle-789';
+      const userId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const vehicleId = 'vehicle-uuid-789';
       const entry = await service.info(
         'vehicle',
@@ -96,7 +96,7 @@ describe('AuditLog Feature Integration', () => {
 
   describe('Auth logging integration', () => {
     it('should create audit log with auth category for signup', async () => {
-      const userId = 'test-user-auth-123';
+      const userId = '550e8400-e29b-41d4-a716-446655440000';
       const entry = await service.info(
         'auth',
         userId,
@@ -116,7 +116,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create audit log for password reset request', async () => {
-      const userId = 'test-user-auth-456';
+      const userId = '6ba7b810-9dad-11d1-80b4-00c04fd430c8';
       const entry = await service.info(
         'auth',
         userId,
@@ -134,14 +134,14 @@ describe('AuditLog Feature Integration', () => {
 
   describe('Admin logging integration', () => {
     it('should create audit log for admin user creation', async () => {
-      const adminId = 'admin-user-123';
-      const targetAdminSub = 'auth0|target-admin-456';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
+      const targetAdminId = '8f14e45f-ceea-367f-a27f-c9a6d0c67e0e';
       const entry = await service.info(
         'admin',
         adminId,
         'Admin user created: newadmin@example.com',
         'admin_user',
-        targetAdminSub,
+        targetAdminId,
         { email: 'newadmin@example.com', role: 'admin' }
       );
 
@@ -156,14 +156,14 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create audit log for admin revocation', async () => {
-      const adminId = 'admin-user-123';
-      const targetAdminSub = 'auth0|target-admin-789';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
+      const targetAdminId = 'a1b2c3d4-e5f6-7890-1234-567890abcdef';
       const entry = await service.info(
         'admin',
         adminId,
         'Admin user revoked: revoked@example.com',
         'admin_user',
-        targetAdminSub,
+        targetAdminId,
         { email: 'revoked@example.com' }
       );
 
@@ -174,14 +174,14 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create audit log for admin reinstatement', async () => {
-      const adminId = 'admin-user-123';
-      const targetAdminSub = 'auth0|target-admin-reinstated';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
+      const targetAdminId = 'b2c3d4e5-f6a7-8901-2345-678901bcdef0';
       const entry = await service.info(
         'admin',
         adminId,
         'Admin user reinstated: reinstated@example.com',
         'admin_user',
-        targetAdminSub,
+        targetAdminId,
         { email: 'reinstated@example.com' }
       );
 
@@ -194,7 +194,7 @@ describe('AuditLog Feature Integration', () => {
 
   describe('Backup/System logging integration', () => {
     it('should create audit log for backup creation', async () => {
-      const adminId = 'admin-user-backup-123';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const backupId = 'backup-uuid-123';
       const entry = await service.info(
         'system',
@@ -215,7 +215,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create audit log for backup restore', async () => {
-      const adminId = 'admin-user-backup-456';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const backupId = 'backup-uuid-456';
       const entry = await service.info(
         'system',
@@ -233,7 +233,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create error-level audit log for backup failure', async () => {
-      const adminId = 'admin-user-backup-789';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const backupId = 'backup-uuid-789';
       const entry = await service.error(
         'system',
@@ -253,7 +253,7 @@ describe('AuditLog Feature Integration', () => {
     });
 
     it('should create error-level audit log for restore failure', async () => {
-      const adminId = 'admin-user-restore-fail';
+      const adminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
       const backupId = 'backup-uuid-restore-fail';
       const entry = await service.error(
         'system',
diff --git a/backend/src/features/auth/tests/integration/auth.integration.test.ts b/backend/src/features/auth/tests/integration/auth.integration.test.ts
index e783ed2..b7a8345 100644
--- a/backend/src/features/auth/tests/integration/auth.integration.test.ts
+++ b/backend/src/features/auth/tests/integration/auth.integration.test.ts
@@ -19,6 +19,7 @@ jest.mock('../../../../core/plugins/auth.plugin', () => {
   return {
     default: fastifyPlugin(async function (fastify) {
       fastify.decorate('authenticate', async function (request, _reply) {
+        // JWT sub is still auth0|xxx format
         request.user = { sub: 'auth0|test-user-123' };
       });
     }, { name: 'auth-plugin' }),
diff --git a/backend/src/features/auth/tests/unit/auth.service.test.ts b/backend/src/features/auth/tests/unit/auth.service.test.ts
index c698f75..84f0d18 100644
--- a/backend/src/features/auth/tests/unit/auth.service.test.ts
+++ b/backend/src/features/auth/tests/unit/auth.service.test.ts
@@ -103,6 +103,8 @@ describe('AuthService', () => {
         onboardingCompletedAt: null,
         deactivatedAt: null,
         deactivatedBy: null,
+        deletionRequestedAt: null,
+        deletionScheduledFor: null,
         createdAt: new Date(),
         updatedAt: new Date(),
       });
@@ -116,6 +118,8 @@ describe('AuthService', () => {
         onboardingCompletedAt: null,
         deactivatedAt: null,
         deactivatedBy: null,
+        deletionRequestedAt: null,
+        deletionScheduledFor: null,
         createdAt: new Date(),
         updatedAt: new Date(),
       });
@@ -149,6 +153,8 @@ describe('AuthService', () => {
         onboardingCompletedAt: null,
         deactivatedAt: null,
         deactivatedBy: null,
+        deletionRequestedAt: null,
+        deletionScheduledFor: null,
         createdAt: new Date(),
         updatedAt: new Date(),
       });
diff --git a/backend/src/features/fuel-logs/tests/fixtures/fuel-logs.fixtures.json b/backend/src/features/fuel-logs/tests/fixtures/fuel-logs.fixtures.json
index 2bd28f1..b6aeed8 100644
--- a/backend/src/features/fuel-logs/tests/fixtures/fuel-logs.fixtures.json
+++ b/backend/src/features/fuel-logs/tests/fixtures/fuel-logs.fixtures.json
@@ -73,7 +73,7 @@
   },
   "responseWithEfficiency": {
     "id": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
-    "userId": "auth0|user123",
+    "userId": "550e8400-e29b-41d4-a716-446655440000",
     "vehicleId": "550e8400-e29b-41d4-a716-446655440000",
     "dateTime": "2024-01-15T10:30:00Z",
     "odometerReading": 52000,
diff --git a/backend/src/features/maintenance/tests/fixtures/maintenance.fixtures.json b/backend/src/features/maintenance/tests/fixtures/maintenance.fixtures.json
index f551606..8154492 100644
--- a/backend/src/features/maintenance/tests/fixtures/maintenance.fixtures.json
+++ b/backend/src/features/maintenance/tests/fixtures/maintenance.fixtures.json
@@ -99,7 +99,7 @@
   },
   "maintenanceScheduleResponse": {
     "id": "f47ac10b-58cc-4372-a567-0e02b2c3d479",
-    "userId": "auth0|user123",
+    "userId": "550e8400-e29b-41d4-a716-446655440000",
     "vehicleId": "550e8400-e29b-41d4-a716-446655440000",
     "type": "oil_change",
     "category": "routine_maintenance",
diff --git a/backend/src/features/stations/tests/integration/community-stations.api.test.ts b/backend/src/features/stations/tests/integration/community-stations.api.test.ts
index 5ee1bda..71e45bf 100644
--- a/backend/src/features/stations/tests/integration/community-stations.api.test.ts
+++ b/backend/src/features/stations/tests/integration/community-stations.api.test.ts
@@ -12,8 +12,8 @@ describe('Community Stations API Integration Tests', () => {
   let app: FastifyInstance;
   let pool: Pool;
 
-  const testUserId = 'auth0|test-user-123';
-  const testAdminId = 'auth0|test-admin-123';
+  const testUserId = '550e8400-e29b-41d4-a716-446655440000';
+  const testAdminId = '7c9e6679-7425-40de-944b-e07fc1f90ae7';
 
   const mockStationData = {
     name: 'Test Gas Station',
diff --git a/frontend/src/features/admin/__tests__/AdminUsersPage.test.tsx b/frontend/src/features/admin/__tests__/AdminUsersPage.test.tsx
index 191b1bb..4594683 100644
--- a/frontend/src/features/admin/__tests__/AdminUsersPage.test.tsx
+++ b/frontend/src/features/admin/__tests__/AdminUsersPage.test.tsx
@@ -48,7 +48,8 @@ describe('AdminUsersPage', () => {
     mockUseAdminAccess.mockReturnValue({
       isAdmin: true,
       adminRecord: {
-        auth0Sub: 'auth0|123',
+        id: 'admin-uuid-123',
+        userProfileId: 'user-uuid-123',
         email: 'admin@example.com',
         role: 'admin',
         createdAt: '2024-01-01',
diff --git a/frontend/src/features/admin/__tests__/useAdminAccess.test.tsx b/frontend/src/features/admin/__tests__/useAdminAccess.test.tsx
index 4574380..e8a8007 100644
--- a/frontend/src/features/admin/__tests__/useAdminAccess.test.tsx
+++ b/frontend/src/features/admin/__tests__/useAdminAccess.test.tsx
@@ -55,7 +55,8 @@ describe('useAdminAccess', () => {
     mockAdminApi.verifyAccess.mockResolvedValue({
       isAdmin: true,
       adminRecord: {
-        auth0Sub: 'auth0|123',
+        id: 'admin-uuid-123',
+        userProfileId: 'user-uuid-123',
         email: 'admin@example.com',
         role: 'admin',
         createdAt: '2024-01-01',
diff --git a/frontend/src/features/admin/__tests__/useAdmins.test.tsx b/frontend/src/features/admin/__tests__/useAdmins.test.tsx
index 2b1cbb6..9f886f5 100644
--- a/frontend/src/features/admin/__tests__/useAdmins.test.tsx
+++ b/frontend/src/features/admin/__tests__/useAdmins.test.tsx
@@ -42,7 +42,8 @@ describe('Admin user management hooks', () => {
     it('should fetch admin users', async () => {
       const mockAdmins = [
         {
-          auth0Sub: 'auth0|123',
+          id: 'admin-uuid-123',
+          userProfileId: 'user-uuid-123',
           email: 'admin1@example.com',
           role: 'admin',
           createdAt: '2024-01-01',
@@ -68,11 +69,12 @@ describe('Admin user management hooks', () => {
   describe('useCreateAdmin', () => {
     it('should create admin and show success toast', async () => {
       const newAdmin = {
-        auth0Sub: 'auth0|456',
+        id: 'admin-uuid-456',
+        userProfileId: 'user-uuid-456',
         email: 'newadmin@example.com',
         role: 'admin',
         createdAt: '2024-01-01',
-        createdBy: 'auth0|123',
+        createdBy: 'admin-uuid-123',
         revokedAt: null,
         updatedAt: '2024-01-01',
       };
@@ -131,11 +133,11 @@ describe('Admin user management hooks', () => {
         wrapper: createWrapper(),
       });
 
-      result.current.mutate('auth0|123');
+      result.current.mutate('admin-uuid-123');
 
       await waitFor(() => expect(result.current.isSuccess).toBe(true));
 
-      expect(mockAdminApi.revokeAdmin).toHaveBeenCalledWith('auth0|123');
+      expect(mockAdminApi.revokeAdmin).toHaveBeenCalledWith('admin-uuid-123');
       expect(toast.success).toHaveBeenCalledWith('Admin revoked successfully');
     });
   });
@@ -148,11 +150,11 @@ describe('Admin user management hooks', () => {
         wrapper: createWrapper(),
       });
 
-      result.current.mutate('auth0|123');
+      result.current.mutate('admin-uuid-123');
 
       await waitFor(() => expect(result.current.isSuccess).toBe(true));
 
-      expect(mockAdminApi.reinstateAdmin).toHaveBeenCalledWith('auth0|123');
+      expect(mockAdminApi.reinstateAdmin).toHaveBeenCalledWith('admin-uuid-123');
       expect(toast.success).toHaveBeenCalledWith('Admin reinstated successfully');
     });
   });
diff --git a/frontend/src/features/admin/api/admin.api.ts b/frontend/src/features/admin/api/admin.api.ts
index 8382ea3..eac73cd 100644
--- a/frontend/src/features/admin/api/admin.api.ts
+++ b/frontend/src/features/admin/api/admin.api.ts
@@ -101,12 +101,12 @@ export const adminApi = {
     return response.data;
   },
 
-  revokeAdmin: async (auth0Sub: string): Promise<void> => {
-    await apiClient.patch(`/admin/admins/${auth0Sub}/revoke`);
+  revokeAdmin: async (id: string): Promise<void> => {
+    await apiClient.patch(`/admin/admins/${id}/revoke`);
   },
 
-  reinstateAdmin: async (auth0Sub: string): Promise<void> => {
-    await apiClient.patch(`/admin/admins/${auth0Sub}/reinstate`);
+  reinstateAdmin: async (id: string): Promise<void> => {
+    await apiClient.patch(`/admin/admins/${id}/reinstate`);
   },
 
   // Audit logs
@@ -328,62 +328,62 @@ export const adminApi = {
       return response.data;
     },
 
-    get: async (auth0Sub: string): Promise<ManagedUser> => {
+    get: async (userId: string): Promise<ManagedUser> => {
       const response = await apiClient.get<ManagedUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}`
+        `/admin/users/${userId}`
       );
       return response.data;
     },
 
-    getVehicles: async (auth0Sub: string): Promise<AdminUserVehiclesResponse> => {
+    getVehicles: async (userId: string): Promise<AdminUserVehiclesResponse> => {
       const response = await apiClient.get<AdminUserVehiclesResponse>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/vehicles`
+        `/admin/users/${userId}/vehicles`
       );
       return response.data;
     },
 
-    updateTier: async (auth0Sub: string, data: UpdateUserTierRequest): Promise<ManagedUser> => {
+    updateTier: async (userId: string, data: UpdateUserTierRequest): Promise<ManagedUser> => {
       const response = await apiClient.patch<ManagedUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/tier`,
+        `/admin/users/${userId}/tier`,
         data
       );
       return response.data;
     },
 
-    deactivate: async (auth0Sub: string, data?: DeactivateUserRequest): Promise<ManagedUser> => {
+    deactivate: async (userId: string, data?: DeactivateUserRequest): Promise<ManagedUser> => {
       const response = await apiClient.patch<ManagedUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/deactivate`,
+        `/admin/users/${userId}/deactivate`,
         data || {}
       );
       return response.data;
     },
 
-    reactivate: async (auth0Sub: string): Promise<ManagedUser> => {
+    reactivate: async (userId: string): Promise<ManagedUser> => {
       const response = await apiClient.patch<ManagedUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/reactivate`
+        `/admin/users/${userId}/reactivate`
       );
       return response.data;
     },
 
-    updateProfile: async (auth0Sub: string, data: UpdateUserProfileRequest): Promise<ManagedUser> => {
+    updateProfile: async (userId: string, data: UpdateUserProfileRequest): Promise<ManagedUser> => {
       const response = await apiClient.patch<ManagedUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/profile`,
+        `/admin/users/${userId}/profile`,
         data
       );
       return response.data;
     },
 
-    promoteToAdmin: async (auth0Sub: string, data?: PromoteToAdminRequest): Promise<AdminUser> => {
+    promoteToAdmin: async (userId: string, data?: PromoteToAdminRequest): Promise<AdminUser> => {
       const response = await apiClient.patch<AdminUser>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}/promote`,
+        `/admin/users/${userId}/promote`,
         data || {}
       );
       return response.data;
     },
 
-    hardDelete: async (auth0Sub: string, reason?: string): Promise<{ message: string }> => {
+    hardDelete: async (userId: string, reason?: string): Promise<{ message: string }> => {
       const response = await apiClient.delete<{ message: string }>(
-        `/admin/users/${encodeURIComponent(auth0Sub)}`,
+        `/admin/users/${userId}`,
         { params: reason ? { reason } : undefined }
       );
       return response.data;
diff --git a/frontend/src/features/admin/hooks/useAdmins.ts b/frontend/src/features/admin/hooks/useAdmins.ts
index 4170ec8..3df42f6 100644
--- a/frontend/src/features/admin/hooks/useAdmins.ts
+++ b/frontend/src/features/admin/hooks/useAdmins.ts
@@ -51,7 +51,7 @@ export const useRevokeAdmin = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: (auth0Sub: string) => adminApi.revokeAdmin(auth0Sub),
+    mutationFn: (id: string) => adminApi.revokeAdmin(id),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['admins'] });
       toast.success('Admin revoked successfully');
@@ -66,7 +66,7 @@ export const useReinstateAdmin = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: (auth0Sub: string) => adminApi.reinstateAdmin(auth0Sub),
+    mutationFn: (id: string) => adminApi.reinstateAdmin(id),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['admins'] });
       toast.success('Admin reinstated successfully');
diff --git a/frontend/src/features/admin/hooks/useUsers.ts b/frontend/src/features/admin/hooks/useUsers.ts
index d76079a..3d6d9cc 100644
--- a/frontend/src/features/admin/hooks/useUsers.ts
+++ b/frontend/src/features/admin/hooks/useUsers.ts
@@ -29,8 +29,8 @@ interface ApiError {
 export const userQueryKeys = {
   all: ['admin-users'] as const,
   list: (params: ListUsersParams) => [...userQueryKeys.all, 'list', params] as const,
-  detail: (auth0Sub: string) => [...userQueryKeys.all, 'detail', auth0Sub] as const,
-  vehicles: (auth0Sub: string) => [...userQueryKeys.all, 'vehicles', auth0Sub] as const,
+  detail: (userId: string) => [...userQueryKeys.all, 'detail', userId] as const,
+  vehicles: (userId: string) => [...userQueryKeys.all, 'vehicles', userId] as const,
 };
 
 // Query keys for admin stats
@@ -58,13 +58,13 @@ export const useUsers = (params: ListUsersParams = {}) => {
 /**
  * Hook to get a single user's details
  */
-export const useUser = (auth0Sub: string) => {
+export const useUser = (userId: string) => {
   const { isAuthenticated, isLoading } = useAuth0();
 
   return useQuery({
-    queryKey: userQueryKeys.detail(auth0Sub),
-    queryFn: () => adminApi.users.get(auth0Sub),
-    enabled: isAuthenticated && !isLoading && !!auth0Sub,
+    queryKey: userQueryKeys.detail(userId),
+    queryFn: () => adminApi.users.get(userId),
+    enabled: isAuthenticated && !isLoading && !!userId,
     staleTime: 2 * 60 * 1000,
     gcTime: 5 * 60 * 1000,
     retry: 1,
@@ -78,8 +78,8 @@ export const useUpdateUserTier = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ auth0Sub, data }: { auth0Sub: string; data: UpdateUserTierRequest }) =>
-      adminApi.users.updateTier(auth0Sub, data),
+    mutationFn: ({ userId, data }: { userId: string; data: UpdateUserTierRequest }) =>
+      adminApi.users.updateTier(userId, data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('Subscription tier updated');
@@ -101,8 +101,8 @@ export const useDeactivateUser = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ auth0Sub, data }: { auth0Sub: string; data?: DeactivateUserRequest }) =>
-      adminApi.users.deactivate(auth0Sub, data),
+    mutationFn: ({ userId, data }: { userId: string; data?: DeactivateUserRequest }) =>
+      adminApi.users.deactivate(userId, data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('User deactivated');
@@ -124,7 +124,7 @@ export const useReactivateUser = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: (auth0Sub: string) => adminApi.users.reactivate(auth0Sub),
+    mutationFn: (userId: string) => adminApi.users.reactivate(userId),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('User reactivated');
@@ -146,8 +146,8 @@ export const useUpdateUserProfile = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ auth0Sub, data }: { auth0Sub: string; data: UpdateUserProfileRequest }) =>
-      adminApi.users.updateProfile(auth0Sub, data),
+    mutationFn: ({ userId, data }: { userId: string; data: UpdateUserProfileRequest }) =>
+      adminApi.users.updateProfile(userId, data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('User profile updated');
@@ -169,8 +169,8 @@ export const usePromoteToAdmin = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ auth0Sub, data }: { auth0Sub: string; data?: PromoteToAdminRequest }) =>
-      adminApi.users.promoteToAdmin(auth0Sub, data),
+    mutationFn: ({ userId, data }: { userId: string; data?: PromoteToAdminRequest }) =>
+      adminApi.users.promoteToAdmin(userId, data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('User promoted to admin');
@@ -192,8 +192,8 @@ export const useHardDeleteUser = () => {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ auth0Sub, reason }: { auth0Sub: string; reason?: string }) =>
-      adminApi.users.hardDelete(auth0Sub, reason),
+    mutationFn: ({ userId, reason }: { userId: string; reason?: string }) =>
+      adminApi.users.hardDelete(userId, reason),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: userQueryKeys.all });
       toast.success('User permanently deleted');
@@ -228,13 +228,13 @@ export const useAdminStats = () => {
 /**
  * Hook to get a user's vehicles (admin view - year, make, model only)
  */
-export const useUserVehicles = (auth0Sub: string) => {
+export const useUserVehicles = (userId: string) => {
   const { isAuthenticated, isLoading } = useAuth0();
 
   return useQuery({
-    queryKey: userQueryKeys.vehicles(auth0Sub),
-    queryFn: () => adminApi.users.getVehicles(auth0Sub),
-    enabled: isAuthenticated && !isLoading && !!auth0Sub,
+    queryKey: userQueryKeys.vehicles(userId),
+    queryFn: () => adminApi.users.getVehicles(userId),
+    enabled: isAuthenticated && !isLoading && !!userId,
     staleTime: 2 * 60 * 1000,
     gcTime: 5 * 60 * 1000,
     retry: 1,
diff --git a/frontend/src/features/admin/mobile/AdminUsersMobileScreen.tsx b/frontend/src/features/admin/mobile/AdminUsersMobileScreen.tsx
index 4cfc876..d9b5011 100644
--- a/frontend/src/features/admin/mobile/AdminUsersMobileScreen.tsx
+++ b/frontend/src/features/admin/mobile/AdminUsersMobileScreen.tsx
@@ -104,8 +104,8 @@ const VehicleCountBadge: React.FC<{ count: number; onClick?: () => void }> = ({
 );
 
 // Expandable vehicle list component
-const UserVehiclesList: React.FC<{ auth0Sub: string; isOpen: boolean }> = ({ auth0Sub, isOpen }) => {
-  const { data, isLoading, error } = useUserVehicles(auth0Sub);
+const UserVehiclesList: React.FC<{ userId: string; isOpen: boolean }> = ({ userId, isOpen }) => {
+  const { data, isLoading, error } = useUserVehicles(userId);
 
   if (!isOpen) return null;
 
@@ -215,7 +215,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
     (newTier: SubscriptionTier) => {
       if (selectedUser) {
         updateTierMutation.mutate(
-          { auth0Sub: selectedUser.auth0Sub, data: { subscriptionTier: newTier } },
+          { userId: selectedUser.id, data: { subscriptionTier: newTier } },
           {
             onSuccess: () => {
               setShowTierPicker(false);
@@ -232,7 +232,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
   const handleDeactivate = useCallback(() => {
     if (selectedUser) {
       deactivateMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, data: { reason: deactivateReason || undefined } },
+        { userId: selectedUser.id, data: { reason: deactivateReason || undefined } },
         {
           onSuccess: () => {
             setShowDeactivateConfirm(false);
@@ -247,7 +247,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
 
   const handleReactivate = useCallback(() => {
     if (selectedUser) {
-      reactivateMutation.mutate(selectedUser.auth0Sub, {
+      reactivateMutation.mutate(selectedUser.id, {
         onSuccess: () => {
           setShowUserActions(false);
           setSelectedUser(null);
@@ -276,7 +276,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
       }
       if (Object.keys(updates).length > 0) {
         updateProfileMutation.mutate(
-          { auth0Sub: selectedUser.auth0Sub, data: updates },
+          { userId: selectedUser.id, data: updates },
           {
             onSuccess: () => {
               setShowEditModal(false);
@@ -306,7 +306,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
   const handlePromoteConfirm = useCallback(() => {
     if (selectedUser) {
       promoteToAdminMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, data: { role: promoteRole } },
+        { userId: selectedUser.id, data: { role: promoteRole } },
         {
           onSuccess: () => {
             setShowPromoteModal(false);
@@ -332,7 +332,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
   const handleHardDeleteConfirm = useCallback(() => {
     if (selectedUser && hardDeleteConfirmText === 'DELETE') {
       hardDeleteMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, reason: hardDeleteReason || undefined },
+        { userId: selectedUser.id, reason: hardDeleteReason || undefined },
         {
           onSuccess: () => {
             setShowHardDeleteModal(false);
@@ -509,7 +509,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
         {users.length > 0 && (
           <div className="space-y-3">
             {users.map((user) => (
-              <GlassCard key={user.auth0Sub} padding="md">
+              <GlassCard key={user.id} padding="md">
                 <button
                   onClick={() => handleUserClick(user)}
                   className="w-full text-left min-h-[44px]"
@@ -526,7 +526,7 @@ export const AdminUsersMobileScreen: React.FC = () => {
                         <VehicleCountBadge
                           count={user.vehicleCount}
                           onClick={user.vehicleCount > 0 ? () => setExpandedUserId(
-                            expandedUserId === user.auth0Sub ? null : user.auth0Sub
+                            expandedUserId === user.id ? null : user.id
                           ) : undefined}
                         />
                         <StatusBadge active={!user.deactivatedAt} />
@@ -543,8 +543,8 @@ export const AdminUsersMobileScreen: React.FC = () => {
                   </div>
                 </button>
                 <UserVehiclesList
-                  auth0Sub={user.auth0Sub}
-                  isOpen={expandedUserId === user.auth0Sub}
+                  userId={user.id}
+                  isOpen={expandedUserId === user.id}
                 />
               </GlassCard>
             ))}
diff --git a/frontend/src/features/admin/types/admin.types.ts b/frontend/src/features/admin/types/admin.types.ts
index 6ae46bf..4b9ba60 100644
--- a/frontend/src/features/admin/types/admin.types.ts
+++ b/frontend/src/features/admin/types/admin.types.ts
@@ -5,7 +5,8 @@
 
 // Admin user types
 export interface AdminUser {
-  auth0Sub: string;
+  id: string;
+  userProfileId: string;
   email: string;
   role: string;
   createdAt: string;
diff --git a/frontend/src/pages/admin/AdminUsersPage.tsx b/frontend/src/pages/admin/AdminUsersPage.tsx
index d4e5f16..79e60c1 100644
--- a/frontend/src/pages/admin/AdminUsersPage.tsx
+++ b/frontend/src/pages/admin/AdminUsersPage.tsx
@@ -71,8 +71,8 @@ import { AdminSectionHeader } from '../../features/admin/components';
 const PAGE_SIZE_OPTIONS = [10, 20, 50, 100];
 
 // Expandable vehicle row component
-const UserVehiclesRow: React.FC<{ auth0Sub: string; isOpen: boolean }> = ({ auth0Sub, isOpen }) => {
-  const { data, isLoading, error } = useUserVehicles(auth0Sub);
+const UserVehiclesRow: React.FC<{ userId: string; isOpen: boolean }> = ({ userId, isOpen }) => {
+  const { data, isLoading, error } = useUserVehicles(userId);
 
   if (!isOpen) return null;
 
@@ -222,8 +222,8 @@ export const AdminUsersPage: React.FC = () => {
   }, []);
 
   const handleTierChange = useCallback(
-    (auth0Sub: string, newTier: SubscriptionTier) => {
-      updateTierMutation.mutate({ auth0Sub, data: { subscriptionTier: newTier } });
+    (userId: string, newTier: SubscriptionTier) => {
+      updateTierMutation.mutate({ userId, data: { subscriptionTier: newTier } });
     },
     [updateTierMutation]
   );
@@ -246,7 +246,7 @@ export const AdminUsersPage: React.FC = () => {
   const handleDeactivateConfirm = useCallback(() => {
     if (selectedUser) {
       deactivateMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, data: { reason: deactivateReason || undefined } },
+        { userId: selectedUser.id, data: { reason: deactivateReason || undefined } },
         {
           onSuccess: () => {
             setDeactivateDialogOpen(false);
@@ -260,7 +260,7 @@ export const AdminUsersPage: React.FC = () => {
 
   const handleReactivate = useCallback(() => {
     if (selectedUser) {
-      reactivateMutation.mutate(selectedUser.auth0Sub);
+      reactivateMutation.mutate(selectedUser.id);
       setAnchorEl(null);
       setSelectedUser(null);
     }
@@ -286,7 +286,7 @@ export const AdminUsersPage: React.FC = () => {
       }
       if (Object.keys(updates).length > 0) {
         updateProfileMutation.mutate(
-          { auth0Sub: selectedUser.auth0Sub, data: updates },
+          { userId: selectedUser.id, data: updates },
           {
             onSuccess: () => {
               setEditDialogOpen(false);
@@ -316,7 +316,7 @@ export const AdminUsersPage: React.FC = () => {
   const handlePromoteConfirm = useCallback(() => {
     if (selectedUser) {
       promoteToAdminMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, data: { role: promoteRole } },
+        { userId: selectedUser.id, data: { role: promoteRole } },
         {
           onSuccess: () => {
             setPromoteDialogOpen(false);
@@ -342,7 +342,7 @@ export const AdminUsersPage: React.FC = () => {
   const handleHardDeleteConfirm = useCallback(() => {
     if (selectedUser && hardDeleteConfirmText === 'DELETE') {
       hardDeleteMutation.mutate(
-        { auth0Sub: selectedUser.auth0Sub, reason: hardDeleteReason || undefined },
+        { userId: selectedUser.id, reason: hardDeleteReason || undefined },
         {
           onSuccess: () => {
             setHardDeleteDialogOpen(false);
@@ -496,11 +496,11 @@ export const AdminUsersPage: React.FC = () => {
                 </TableHead>
                 <TableBody>
                   {users.map((user) => (
-                    <React.Fragment key={user.auth0Sub}>
+                    <React.Fragment key={user.id}>
                       <TableRow
                         sx={{
                           opacity: user.deactivatedAt ? 0.6 : 1,
-                          '& > *': { borderBottom: expandedRow === user.auth0Sub ? 'unset' : undefined },
+                          '& > *': { borderBottom: expandedRow === user.id ? 'unset' : undefined },
                         }}
                       >
                         <TableCell>{user.email}</TableCell>
@@ -510,7 +510,7 @@ export const AdminUsersPage: React.FC = () => {
                             <Select
                               value={user.subscriptionTier}
                               onChange={(e) =>
-                                handleTierChange(user.auth0Sub, e.target.value as SubscriptionTier)
+                                handleTierChange(user.id, e.target.value as SubscriptionTier)
                               }
                               disabled={!!user.deactivatedAt || updateTierMutation.isPending}
                               size="small"
@@ -527,12 +527,12 @@ export const AdminUsersPage: React.FC = () => {
                               <IconButton
                                 size="small"
                                 onClick={() => setExpandedRow(
-                                  expandedRow === user.auth0Sub ? null : user.auth0Sub
+                                  expandedRow === user.id ? null : user.id
                                 )}
                                 aria-label="show vehicles"
                                 sx={{ minWidth: 44, minHeight: 44 }}
                               >
-                                {expandedRow === user.auth0Sub ? (
+                                {expandedRow === user.id ? (
                                   <KeyboardArrowUp fontSize="small" />
                                 ) : (
                                   <KeyboardArrowDown fontSize="small" />
@@ -569,8 +569,8 @@ export const AdminUsersPage: React.FC = () => {
                         </TableCell>
                       </TableRow>
                       <UserVehiclesRow
-                        auth0Sub={user.auth0Sub}
-                        isOpen={expandedRow === user.auth0Sub}
+                        userId={user.id}
+                        isOpen={expandedRow === user.id}
                       />
                     </React.Fragment>
                   ))}