diff --git a/app/celery/scheduled_tasks.py b/app/celery/scheduled_tasks.py
index af072d91b..f8b966e84 100644
--- a/app/celery/scheduled_tasks.py
+++ b/app/celery/scheduled_tasks.py
@@ -97,7 +97,7 @@ def delete_invitations():
 @statsd(namespace="tasks")
 def switch_current_sms_provider_on_slow_delivery():
     """
-    Switch providers if there are at least two slow delivery notifications (more than four minutes)
+    Switch providers if at least 10% of notifications took more than four minutes to be delivered
     in the last ten minutes. Search from the time we last switched to the current provider.
     """
     current_provider = get_current_provider('sms')
diff --git a/app/dao/notifications_dao.py b/app/dao/notifications_dao.py
index 534f6d015..d693bde25 100644
--- a/app/dao/notifications_dao.py
+++ b/app/dao/notifications_dao.py
@@ -484,7 +484,7 @@ def is_delivery_slow_for_provider(
     ).filter(
         Notification.created_at >= created_at,
         Notification.sent_at.isnot(None),
-        Notification.status.in_([NOTIFICATION_DELIVERED, NOTIFICATION_SENDING]),
+        Notification.status.in_([NOTIFICATION_DELIVERED, NOTIFICATION_PENDING, NOTIFICATION_SENDING]),
         Notification.sent_by == provider,
         Notification.key_type != KEY_TYPE_TEST
     ).group_by("slow").all()
diff --git a/tests/app/dao/notification_dao/test_notification_dao.py b/tests/app/dao/notification_dao/test_notification_dao.py
index 90dc73035..0776a45fe 100644
--- a/tests/app/dao/notification_dao/test_notification_dao.py
+++ b/tests/app/dao/notification_dao/test_notification_dao.py
@@ -45,6 +45,7 @@ from app.models import (
     NOTIFICATION_STATUS_TYPES_FAILED,
     NOTIFICATION_TEMPORARY_FAILURE,
     NOTIFICATION_SENDING,
+    NOTIFICATION_PENDING,
     NOTIFICATION_SENT,
     NOTIFICATION_DELIVERED,
     KEY_TYPE_NORMAL,
@@ -1267,15 +1268,16 @@ def test_is_delivery_slow_for_provider(
 
 
 @pytest.mark.parametrize("options,expected_result", [
-    ({"status": NOTIFICATION_TEMPORARY_FAILURE, "sent_by": "mmg"}, False),
-    ({"status": NOTIFICATION_DELIVERED, "sent_by": "firetext"}, False),
     ({"status": NOTIFICATION_DELIVERED, "sent_by": "mmg"}, True),
+    ({"status": NOTIFICATION_PENDING, "sent_by": "mmg"}, True),
+    ({"status": NOTIFICATION_SENDING, "sent_by": "mmg"}, True),
+
+    ({"status": NOTIFICATION_TEMPORARY_FAILURE, "sent_by": "mmg"}, False),
     ({"status": NOTIFICATION_DELIVERED, "sent_by": "mmg", "sent_at": None}, False),
     ({"status": NOTIFICATION_DELIVERED, "sent_by": "mmg", "key_type": KEY_TYPE_TEST}, False),
     ({"status": NOTIFICATION_SENDING, "sent_by": "firetext"}, False),
-    ({"status": NOTIFICATION_SENDING, "sent_by": "mmg"}, True),
-    ({"status": NOTIFICATION_SENDING, "sent_by": "mmg", "sent_at": None}, False),
-    ({"status": NOTIFICATION_SENDING, "sent_by": "mmg", "key_type": KEY_TYPE_TEST}, False),
+    ({"status": NOTIFICATION_DELIVERED, "sent_by": "firetext"}, False),
+
 ])
 @freeze_time("2018-12-04 12:00:00.000000")
 def test_delivery_is_delivery_slow_for_provider_filters_out_notifications_it_should_not_count(