diff --git a/app/clients/sms/aws_pinpoint.py b/app/clients/sms/aws_pinpoint.py
index bdb3ba7fa7..1ce3255d5c 100644
--- a/app/clients/sms/aws_pinpoint.py
+++ b/app/clients/sms/aws_pinpoint.py
@@ -24,6 +24,8 @@ def get_name(self):
     def send_sms(self, to, content, reference, multi=True, sender=None, template_id=None):
         messageType = "TRANSACTIONAL"
         matched = False
+        opted_out = False
+        response = {}
 
         if template_id is not None and str(template_id) in self.current_app.config["AWS_PINPOINT_SC_TEMPLATE_IDS"]:
             pool_id = self.current_app.config["AWS_PINPOINT_SC_POOL_ID"]
@@ -32,6 +34,7 @@ def send_sms(self, to, content, reference, multi=True, sender=None, template_id=
 
         for match in phonenumbers.PhoneNumberMatcher(to, "US"):
             matched = True
+            opted_out = False
             to = phonenumbers.format_number(match.number, phonenumbers.PhoneNumberFormat.E164)
             destinationNumber = to
 
@@ -44,15 +47,21 @@ def send_sms(self, to, content, reference, multi=True, sender=None, template_id=
                     MessageType=messageType,
                     ConfigurationSetName=self.current_app.config["AWS_PINPOINT_CONFIGURATION_SET_NAME"],
                 )
+            except self._client.exceptions.ConflictException as e:
+                if e.response.get("Reason") == "DESTINATION_PHONE_NUMBER_OPTED_OUT":
+                    opted_out = True
+                else:
+                    raise e
+
             except Exception as e:
                 self.statsd_client.incr("clients.pinpoint.error")
-                raise Exception(e)
+                raise e
             finally:
                 elapsed_time = monotonic() - start_time
                 self.current_app.logger.info("AWS Pinpoint request finished in {}".format(elapsed_time))
                 self.statsd_client.timing("clients.pinpoint.request-time", elapsed_time)
                 self.statsd_client.incr("clients.pinpoint.success")
-            return response["MessageId"]
+            return "opted_out" if opted_out else response.get("MessageId")
 
         if not matched:
             self.statsd_client.incr("clients.pinpoint.error")
diff --git a/app/delivery/send_to_providers.py b/app/delivery/send_to_providers.py
index 331e846b7d..b3e4dcaefe 100644
--- a/app/delivery/send_to_providers.py
+++ b/app/delivery/send_to_providers.py
@@ -43,6 +43,7 @@
     EMAIL_TYPE,
     KEY_TYPE_TEST,
     NOTIFICATION_CONTAINS_PII,
+    NOTIFICATION_PERMANENT_FAILURE,
     NOTIFICATION_SENDING,
     NOTIFICATION_SENT,
     NOTIFICATION_TECHNICAL_FAILURE,
@@ -118,7 +119,10 @@ def send_sms_to_provider(notification):
             else:
                 notification.reference = reference
                 notification.billable_units = template.fragment_count
-                update_notification_to_sending(notification, provider)
+                if reference == "opted_out":
+                    update_notification_to_opted_out(notification, provider)
+                else:
+                    update_notification_to_sending(notification, provider)
 
         # Record StatsD stats to compute SLOs
         statsd_client.timing_with_dates("sms.total-time", notification.sent_at, notification.created_at)
@@ -340,6 +344,14 @@ def update_notification_to_sending(notification, provider):
     dao_update_notification(notification)
 
 
+def update_notification_to_opted_out(notification, provider):
+    notification.sent_at = datetime.utcnow()
+    notification.sent_by = provider.get_name()
+    notification.status = NOTIFICATION_PERMANENT_FAILURE
+    notification.provider_response = "Phone number is opted out"
+    dao_update_notification(notification)
+
+
 def provider_to_use(
     notification_type: str,
     notification_id: UUID,
diff --git a/tests/app/clients/test_aws_pinpoint.py b/tests/app/clients/test_aws_pinpoint.py
index ad7546d1ad..33d1d65225 100644
--- a/tests/app/clients/test_aws_pinpoint.py
+++ b/tests/app/clients/test_aws_pinpoint.py
@@ -71,3 +71,15 @@ def test_send_sms_returns_raises_error_if_there_is_no_valid_number_is_found(noti
         aws_pinpoint_client.send_sms(to, content, reference)
 
     assert "No valid numbers found for SMS delivery" in str(excinfo.value)
+
+
+def test_handles_opted_out_numbers(notify_api, mocker, sample_template):
+    conflict_error = aws_pinpoint_client._client.exceptions.ConflictException(
+        error_response={"Reason": "DESTINATION_PHONE_NUMBER_OPTED_OUT"}, operation_name="send_text_message"
+    )
+    mocker.patch("app.aws_pinpoint_client._client.send_text_message", side_effect=conflict_error)
+
+    to = "6135555555"
+    content = "foo"
+    reference = "ref"
+    assert aws_pinpoint_client.send_sms(to, content, reference=reference, template_id=sample_template.id) == "opted_out"
diff --git a/tests/app/delivery/test_send_to_providers.py b/tests/app/delivery/test_send_to_providers.py
index 05482eca2d..374f478394 100644
--- a/tests/app/delivery/test_send_to_providers.py
+++ b/tests/app/delivery/test_send_to_providers.py
@@ -189,6 +189,31 @@ def test_should_return_highest_priority_active_provider(restore_provider_details
     assert send_to_providers.provider_to_use("sms", "1234").name == first.identifier
 
 
+def test_should_handle_opted_out_phone_numbers_if_using_pinpoint(notify_api, sample_template, mocker):
+    mocker.patch("app.aws_pinpoint_client.send_sms", return_value="opted_out")
+    db_notification = save_notification(
+        create_notification(
+            template=sample_template,
+            to_field="+16135551234",
+            status="created",
+            reply_to_text=sample_template.service.get_default_sms_sender(),
+        )
+    )
+
+    with set_config_values(
+        notify_api,
+        {
+            "AWS_PINPOINT_SC_POOL_ID": "sc_pool_id",
+            "AWS_PINPOINT_DEFAULT_POOL_ID": "default_pool_id",
+        },
+    ):
+        send_to_providers.send_sms_to_provider(db_notification)
+
+        notification = Notification.query.filter_by(id=db_notification.id).one()
+        assert notification.status == "permanent-failure"
+        assert notification.provider_response == "Phone number is opted out"
+
+
 def test_should_send_personalised_template_to_correct_sms_provider_and_persist(sample_sms_template_with_html, mocker):
     db_notification = save_notification(
         create_notification(