diff --git a/src/components/Connection/GRDFConnect/StepIdentity.tsx b/src/components/Connection/GRDFConnect/StepIdentity.tsx
index b16b386291e6d64421522809b41de3f2f49bf7c5..4ba5e56579766252c2dbff3a9d7a7334b131c578 100644
--- a/src/components/Connection/GRDFConnect/StepIdentity.tsx
+++ b/src/components/Connection/GRDFConnect/StepIdentity.tsx
@@ -64,6 +64,7 @@ export const StepIdentity = ({
         type="number"
         id="zipCode"
         name="zipCode"
+        required
         value={formData.postalCode}
         onChange={e =>
           setFormData(prev => ({ ...prev, postalCode: e.target.value }))