diff --git a/app/main/views/service_settings.py b/app/main/views/service_settings.py
index 55f7ade46..79d823084 100644
--- a/app/main/views/service_settings.py
+++ b/app/main/views/service_settings.py
@@ -502,7 +502,7 @@ def service_set_sms_prefix(service_id):
     if form.validate_on_submit():
         service_api_client.update_service(
             current_service['id'],
-            prefix_sms_with_service_name=(form.enabled.data == 'on')
+            prefix_sms=(form.enabled.data == 'on')
         )
         return redirect(url_for('.service_settings', service_id=service_id))
 
diff --git a/app/notify_client/service_api_client.py b/app/notify_client/service_api_client.py
index 3667ecba2..2d7b1975b 100644
--- a/app/notify_client/service_api_client.py
+++ b/app/notify_client/service_api_client.py
@@ -107,7 +107,7 @@ class ServiceAPIClient(NotifyAdminAPIClient):
             'permissions',
             'organisation_type',
             'free_sms_fragment_limit',
-            'prefix_sms_with_service_name',
+            'prefix_sms',
         }
         if disallowed_attributes:
             raise TypeError('Not allowed to update service attributes: {}'.format(
diff --git a/tests/app/main/views/test_service_settings.py b/tests/app/main/views/test_service_settings.py
index ca180e3a6..08d3d19fa 100644
--- a/tests/app/main/views/test_service_settings.py
+++ b/tests/app/main/views/test_service_settings.py
@@ -2108,5 +2108,5 @@ def test_updates_sms_prefixing(
     )
     mock_update_service.assert_called_once_with(
         service_id=SERVICE_ONE_ID,
-        prefix_sms_with_service_name=expected_api_argument,
+        prefix_sms=expected_api_argument,
     )