diff --git a/BigQueryDataTransfer/src/V1/CreateTransferConfigRequest.php b/BigQueryDataTransfer/src/V1/CreateTransferConfigRequest.php
index 8e99c30aded4..82eca15da99b 100644
--- a/BigQueryDataTransfer/src/V1/CreateTransferConfigRequest.php
+++ b/BigQueryDataTransfer/src/V1/CreateTransferConfigRequest.php
@@ -15,6 +15,10 @@
  * associated with the user id corresponding to the authorization info.
  * Otherwise, the transfer configuration will be associated with the calling
  * user.
+ * When using a cross project service account for creating a transfer config,
+ * you must enable cross project service account usage. For more information,
+ * see [Disable attachment of service accounts to resources in other
+ * projects](https://cloud.google.com/resource-manager/docs/organization-policy/restricting-service-accounts#disable_cross_project_service_accounts).
  *
  * Generated from protobuf message <code>google.cloud.bigquery.datatransfer.v1.CreateTransferConfigRequest</code>
  */
diff --git a/BigQueryDataTransfer/src/V1/UpdateTransferConfigRequest.php b/BigQueryDataTransfer/src/V1/UpdateTransferConfigRequest.php
index 9e74ef9b894c..f3f6ca93c1e7 100644
--- a/BigQueryDataTransfer/src/V1/UpdateTransferConfigRequest.php
+++ b/BigQueryDataTransfer/src/V1/UpdateTransferConfigRequest.php
@@ -11,6 +11,10 @@
 /**
  * A request to update a transfer configuration. To update the user id of the
  * transfer configuration, authorization info needs to be provided.
+ * When using a cross project service account for updating a transfer config,
+ * you must enable cross project service account usage. For more information,
+ * see [Disable attachment of service accounts to resources in other
+ * projects](https://cloud.google.com/resource-manager/docs/organization-policy/restricting-service-accounts#disable_cross_project_service_accounts).
  *
  * Generated from protobuf message <code>google.cloud.bigquery.datatransfer.v1.UpdateTransferConfigRequest</code>
  */