diff --git a/app/main/views/jobs.py b/app/main/views/jobs.py
index 8d1bc5b48..fb5ffe367 100644
--- a/app/main/views/jobs.py
+++ b/app/main/views/jobs.py
@@ -176,10 +176,10 @@ def cancel_job(service_id, job_id):
 def cancel_letter_job(service_id, job_id):
     if request.method == 'POST':
         job = job_api_client.get_job(service_id, job_id)['data']
-        notifications = notification_api_client.get_notifications_for_service(
-            job['service'], job['id']
-        )['notifications']
-        if job['job_status'] != 'finished' or len(notifications) < job['notification_count']:
+        notification_count = notification_api_client.get_notification_count_for_job_id(
+            service_id=service_id, job_id=job_id
+        )
+        if job['job_status'] != 'finished' or notification_count < job['notification_count']:
             flash("We are still processing these letters, please try again in a minute.", 'try again')
             return view_job(service_id, job_id)
         try:
diff --git a/app/notify_client/notification_api_client.py b/app/notify_client/notification_api_client.py
index d474214bc..341d10234 100644
--- a/app/notify_client/notification_api_client.py
+++ b/app/notify_client/notification_api_client.py
@@ -127,5 +127,8 @@ class NotificationApiClient(NotifyAdminAPIClient):
             }
         )
 
+    def get_notification_count_for_job_id(self, *, service_id, job_id):
+        return self.get(url='/service/{}/job/{}/notification_count'.format(service_id, job_id))["count"]
+
 
 notification_api_client = NotificationApiClient()
diff --git a/tests/app/main/views/test_jobs.py b/tests/app/main/views/test_jobs.py
index 2f8c9352d..745dccd2f 100644
--- a/tests/app/main/views/test_jobs.py
+++ b/tests/app/main/views/test_jobs.py
@@ -504,10 +504,8 @@ def test_should_cancel_letter_job(
     mocker.patch('app.job_api_client.get_job', side_effect=[{"data": job}])
     notifications_json = notification_json(SERVICE_ONE_ID, job=job, status="created", template_type="letter")
     mocker.patch('app.job_api_client.get_job', side_effect=[{"data": job}])
-    mocker.patch(
-        'app.notification_api_client.get_notifications_for_service',
-        side_effect=[notifications_json]
-    )
+    mocker.patch('app.notification_api_client.get_notifications_for_service', return_value=notifications_json)
+    mocker.patch('app.notification_api_client.get_notification_count_for_job_id', return_value=5)
     mock_cancel = mocker.patch('app.main.jobs.job_api_client.cancel_letter_job', return_value=5)
     client_request.post(
         'main.cancel_letter_job',
@@ -623,9 +621,9 @@ def test_dont_cancel_letter_job_when_to_early_to_cancel(
     notifications_json = notification_json(
         SERVICE_ONE_ID, job=job, status="created", template_type="letter", rows=number_of_processed_notifications
     )
+    mocker.patch('app.notification_api_client.get_notifications_for_service', return_value=notifications_json)
     mocker.patch(
-        'app.notification_api_client.get_notifications_for_service',
-        side_effect=[notifications_json, notifications_json]
+        'app.notification_api_client.get_notification_count_for_job_id', return_value=number_of_processed_notifications
     )
 
     mock_cancel = mocker.patch('app.main.jobs.job_api_client.cancel_letter_job')
diff --git a/tests/app/notify_client/test_notification_client.py b/tests/app/notify_client/test_notification_client.py
index f9a90f702..1975a3412 100644
--- a/tests/app/notify_client/test_notification_client.py
+++ b/tests/app/notify_client/test_notification_client.py
@@ -118,3 +118,11 @@ def test_update_notification_to_cancelled(mocker):
         url='/service/foo/notifications/bar/cancel',
         data={},
     )
+
+
+def test_get_notification_count_for_job_id(mocker):
+    mock_get = mocker.patch('app.notify_client.notification_api_client.NotificationApiClient.get')
+    NotificationApiClient().get_notification_count_for_job_id(service_id='foo', job_id='bar')
+    mock_get.assert_called_once_with(
+        url='/service/foo/job/bar/notification_count',
+    )