diff --git a/backend/benefit/messages/serializers.py b/backend/benefit/messages/serializers.py
index 395bb78ea8..6aafc26df0 100644
--- a/backend/benefit/messages/serializers.py
+++ b/backend/benefit/messages/serializers.py
@@ -30,6 +30,8 @@ class Meta:
         ApplicationStatus.RECEIVED,
         ApplicationStatus.HANDLING,
         ApplicationStatus.ADDITIONAL_INFORMATION_NEEDED,
+        ApplicationStatus.ACCEPTED,
+        ApplicationStatus.REJECTED,
     ]
 
     def validate(self, data):  # noqa: C901
@@ -45,12 +47,16 @@ def validate(self, data):  # noqa: C901
         if settings.NEXT_PUBLIC_MOCK_FLAG:
             if not (user and user.is_authenticated):
                 user = get_user_model().objects.all().order_by("username").first()
-        elif not user.is_handler():
+
+        if not user.is_handler():
             company = get_company_from_request(request)
             if company != application.company:
                 raise PermissionDenied(_("You are not allowed to do this action"))
 
-            if application.status not in self.APPLICANT_MESSAGE_ALLOWED_STATUSES:
+            if (
+                application.status not in self.APPLICANT_MESSAGE_ALLOWED_STATUSES
+                or application.archived
+            ):
                 raise serializers.ValidationError(
                     _(
                         "Cannot do this action because "
diff --git a/backend/benefit/messages/tests/test_api.py b/backend/benefit/messages/tests/test_api.py
index b2b62733c9..69d1f59edb 100644
--- a/backend/benefit/messages/tests/test_api.py
+++ b/backend/benefit/messages/tests/test_api.py
@@ -236,15 +236,17 @@ def test_create_handler_message_invalid(handler_api_client, handling_application
 
 
 @pytest.mark.parametrize(
-    "status,expected_result",
+    "status, archived, expected_result",
     [
-        (ApplicationStatus.DRAFT, 400),
-        (ApplicationStatus.RECEIVED, 201),
-        (ApplicationStatus.HANDLING, 201),
-        (ApplicationStatus.ADDITIONAL_INFORMATION_NEEDED, 201),
-        (ApplicationStatus.ACCEPTED, 400),
-        (ApplicationStatus.REJECTED, 400),
-        (ApplicationStatus.CANCELLED, 400),
+        (ApplicationStatus.DRAFT, False, 400),
+        (ApplicationStatus.RECEIVED, False, 201),
+        (ApplicationStatus.HANDLING, False, 201),
+        (ApplicationStatus.ADDITIONAL_INFORMATION_NEEDED, False, 201),
+        (ApplicationStatus.ACCEPTED, False, 201),
+        (ApplicationStatus.REJECTED, False, 201),
+        (ApplicationStatus.ACCEPTED, True, 400),
+        (ApplicationStatus.REJECTED, True, 400),
+        (ApplicationStatus.CANCELLED, False, 400),
     ],
 )
 def test_applicant_send_first_message(
@@ -252,12 +254,14 @@ def test_applicant_send_first_message(
     handling_application,
     mock_get_organisation_roles_and_create_company,
     status,
+    archived,
     expected_result,
 ):
     msg = deepcopy(SAMPLE_MESSAGE_PAYLOAD)
     msg["message_type"] = MessageType.APPLICANT_MESSAGE
     handling_application.company = mock_get_organisation_roles_and_create_company
     handling_application.status = status
+    handling_application.archived = archived
     handling_application.save()
     result = api_client.post(
         reverse(