diff --git a/apps/api/src/services/__tests__/CampaignService.test.ts b/apps/api/src/services/__tests__/CampaignService.test.ts
index 23eda10..40f62fc 100644
--- a/apps/api/src/services/__tests__/CampaignService.test.ts
+++ b/apps/api/src/services/__tests__/CampaignService.test.ts
@@ -1,8 +1,18 @@
-import {describe, it, expect, beforeEach} from 'vitest';
+import {describe, it, expect, beforeEach, vi} from 'vitest';
 import {CampaignStatus, CampaignAudienceType} from '@plunk/db';
 import {CampaignService} from '../CampaignService';
 import {factories, getPrismaClient} from '../../../../../test/helpers';
 
+// Mock STRIPE_ENABLED for billing limit tests
+vi.mock('../../app/constants.js', async () => {
+  const actual = await vi.importActual('../../app/constants.js');
+  return {
+    ...actual,
+    STRIPE_ENABLED: true,
+    STRIPE_SK: 'sk_test_mock_key_for_testing',
+  };
+});
+
 describe('CampaignService', () => {
   let projectId: string;
   const prisma = getPrismaClient();