diff --git a/docs/public/README.md b/docs/public/README.md
index d32a263..fc4afad 100644
--- a/docs/public/README.md
+++ b/docs/public/README.md
@@ -639,7 +639,8 @@ The control plane emits this event any time it onboards a new tenant. This event
     "tenantName": "tenant$RANDOM",
     "email": "tenant@example.com",
     "tier": "basic",
-    "tenantStatus": "In progress"
+    "tenantStatus": "In progress",
+    "tenantRegistrationId": "guid string"
   }
 }
 ```
diff --git a/resources/functions/tenant-registrations/index.py b/resources/functions/tenant-registrations/index.py
index 74e960c..d7a1d30 100644
--- a/resources/functions/tenant-registrations/index.py
+++ b/resources/functions/tenant-registrations/index.py
@@ -46,6 +46,7 @@ def create_tenant_registration():
     json_body = app.current_event.json_body
     tenant_registration_id = str(uuid.uuid4())
     tenant_data = json_body.get("tenantData", {})
+    tenant_data["tenantRegistrationId"] = tenant_registration_id
     tenant_registration_data = json_body.get("tenantRegistrationData", {})
 
     # Create tenant registration
@@ -76,7 +77,7 @@ def create_tenant_registration():
         json.dumps(
             tenant_registration_data
             | tenant_data
-            | {"tenantId": tenant_id, "tenantRegistrationId": tenant_registration_id}
+            | {"tenantId": tenant_id}
         ),
         onboarding_detail_type,
     )