diff --git a/src/lib/services/gdpr-export.service.ts b/src/lib/services/gdpr-export.service.ts
index be4c330..321a740 100644
--- a/src/lib/services/gdpr-export.service.ts
+++ b/src/lib/services/gdpr-export.service.ts
@@ -28,6 +28,14 @@ import { buildClientBundle, renderBundleHtml } from '@/lib/services/gdpr-bundle-
 
 const EXPIRY_DAYS = 30;
 const PRESIGN_EXPIRY_SECONDS = 7 * 24 * 60 * 60; // 7 days for the email link
+/**
+ * Hard cap on the produced ZIP. Article-15 bundles are JSON+HTML only (no
+ * receipts/contracts) so even very active clients land at <1 MB; anything
+ * larger is almost certainly an unbounded relation we forgot to cap.
+ * Failing the job is safer than uploading a 500MB blob to MinIO + emailing
+ * an unsuspecting client a download link of mystery size.
+ */
+const MAX_BUNDLE_BYTES = 50 * 1024 * 1024;
 
 interface RequestExportInput {
   clientId: string;
@@ -145,6 +153,12 @@ export async function processGdprExportJob(input: ProcessJobInput): Promise<void
     await zip.finalize();
     const buffer = await done;
 
+    if (buffer.length > MAX_BUNDLE_BYTES) {
+      throw new Error(
+        `GDPR bundle exceeded ${MAX_BUNDLE_BYTES} bytes (got ${buffer.length}); refusing to upload`,
+      );
+    }
+
     const port = await db.query.ports.findFirst({ where: eq(ports.id, input.portId) });
     const portSlug = port?.slug ?? 'unknown';
     const storageKey = `${portSlug}/gdpr-exports/${input.clientId}/${input.exportId}.zip`;