diff --git a/app/dao/fact_notification_status_dao.py b/app/dao/fact_notification_status_dao.py
index 61b997688..c37dae011 100644
--- a/app/dao/fact_notification_status_dao.py
+++ b/app/dao/fact_notification_status_dao.py
@@ -39,6 +39,13 @@ def update_fact_notification_status(process_day, notification_type, service_id):
     start_date = get_london_midnight_in_utc(process_day)
     end_date = get_london_midnight_in_utc(process_day + timedelta(days=1))
 
+    # delete any existing rows in case some no longer exist e.g. if all messages are sent
+    FactNotificationStatus.query.filter(
+        FactNotificationStatus.bst_date == process_day,
+        FactNotificationStatus.notification_type == notification_type,
+        FactNotificationStatus.service_id == service_id,
+    ).delete()
+
     # query notifications or notification_history for the day, depending on their data retention
     service = Service.query.get(service_id)
     source_table = get_notification_table_to_use(
@@ -71,30 +78,22 @@ def update_fact_notification_status(process_day, notification_type, service_id):
         source_table.status
     )
 
-    stmt = insert(FactNotificationStatus.__table__).from_select(
-        [
-            FactNotificationStatus.bst_date,
-            FactNotificationStatus.template_id,
-            FactNotificationStatus.service_id,
-            FactNotificationStatus.job_id,
-            FactNotificationStatus.notification_type,
-            FactNotificationStatus.key_type,
-            FactNotificationStatus.notification_status,
-            FactNotificationStatus.notification_count
-        ],
-        query
+    db.session.connection().execute(
+        insert(FactNotificationStatus.__table__).from_select(
+            [
+                FactNotificationStatus.bst_date,
+                FactNotificationStatus.template_id,
+                FactNotificationStatus.service_id,
+                FactNotificationStatus.job_id,
+                FactNotificationStatus.notification_type,
+                FactNotificationStatus.key_type,
+                FactNotificationStatus.notification_status,
+                FactNotificationStatus.notification_count
+            ],
+            query
+        )
     )
 
-    stmt = stmt.on_conflict_do_update(
-        constraint="ft_notification_status_pkey",
-        set_={
-            FactNotificationStatus.notification_count: stmt.excluded.notification_count,
-            FactNotificationStatus.updated_at: datetime.utcnow()
-        }
-    )
-
-    db.session.connection().execute(stmt)
-
 
 def fetch_notification_status_for_service_by_month(start_date, end_date, service_id):
     return db.session.query(
diff --git a/tests/app/celery/test_reporting_tasks.py b/tests/app/celery/test_reporting_tasks.py
index 1e83161f7..3b5f5b701 100644
--- a/tests/app/celery/test_reporting_tasks.py
+++ b/tests/app/celery/test_reporting_tasks.py
@@ -599,9 +599,10 @@ def test_create_nightly_notification_status_for_service_and_day(notify_db_sessio
 def test_create_nightly_notification_status_for_service_and_day_overwrites_old_data(notify_db_session):
     first_service = create_service(service_name='First Service')
     first_template = create_template(service=first_service)
-    create_notification(template=first_template, status='delivered')
-
     process_day = date.today()
+
+    # first run: one notification, expect one row (just one status)
+    notification = create_notification(template=first_template, status='sending')
     create_nightly_notification_status_for_service_and_day(str(process_day), first_service.id, 'sms')
 
     new_fact_data = FactNotificationStatus.query.order_by(
@@ -611,8 +612,11 @@ def test_create_nightly_notification_status_for_service_and_day_overwrites_old_d
 
     assert len(new_fact_data) == 1
     assert new_fact_data[0].notification_count == 1
+    assert new_fact_data[0].notification_status == 'sending'
 
-    create_notification(template=first_template, status='delivered')
+    # second run: status changed, still expect one row (one status)
+    notification.status = 'delivered'
+    create_notification(template=first_template, status='created')
     create_nightly_notification_status_for_service_and_day(str(process_day), first_service.id, 'sms')
 
     updated_fact_data = FactNotificationStatus.query.order_by(
@@ -620,8 +624,11 @@ def test_create_nightly_notification_status_for_service_and_day_overwrites_old_d
         FactNotificationStatus.notification_type
     ).all()
 
-    assert len(updated_fact_data) == 1
-    assert updated_fact_data[0].notification_count == 2
+    assert len(updated_fact_data) == 2
+    assert updated_fact_data[0].notification_count == 1
+    assert updated_fact_data[0].notification_status == 'created'
+    assert updated_fact_data[1].notification_count == 1
+    assert updated_fact_data[1].notification_status == 'delivered'
 
 
 # the job runs at 12:30am London time. 04/01 is in BST.