diff --git a/google/cloud/bigquery_connection_v1/types/connection.py b/google/cloud/bigquery_connection_v1/types/connection.py
index 3f3a449..ff2a0e9 100644
--- a/google/cloud/bigquery_connection_v1/types/connection.py
+++ b/google/cloud/bigquery_connection_v1/types/connection.py
@@ -294,6 +294,14 @@ class CloudSqlProperties(proto.Message):
             Type of the Cloud SQL database.
         credential (google.cloud.bigquery_connection_v1.types.CloudSqlCredential):
             Input only. Cloud SQL credential.
+        service_account_id (str):
+            Output only. The account ID of the service
+            used for the purpose of this connection.
+            When the connection is used in the context of an
+            operation in BigQuery, this service account will
+            serve as identity being used for connecting to
+            the CloudSQL instance specified in this
+            connection.
     """
 
     class DatabaseType(proto.Enum):
@@ -320,6 +328,10 @@ class DatabaseType(proto.Enum):
         number=4,
         message="CloudSqlCredential",
     )
+    service_account_id = proto.Field(
+        proto.STRING,
+        number=5,
+    )
 
 
 class CloudSqlCredential(proto.Message):