diff --git a/app/schemas.py b/app/schemas.py
index 5692b78f8..f4730afa5 100644
--- a/app/schemas.py
+++ b/app/schemas.py
@@ -205,12 +205,16 @@ class ServiceSchema(BaseSchema):
     created_by = field_for(models.Service, 'created_by', required=True)
     organisation_type = field_for(models.Service, 'organisation_type')
     dvla_organisation = field_for(models.Service, 'dvla_organisation')
+    letter_logo_filename = fields.Method(method_name='get_letter_logo_filename')
     permissions = fields.Method("service_permissions")
     email_branding = field_for(models.Service, 'email_branding')
     organisation = field_for(models.Service, 'organisation')
     override_flag = False
     letter_contact_block = fields.Method(method_name="get_letter_contact")
 
+    def get_letter_logo_filename(self, service):
+        return service.dvla_organisation.filename
+
     def service_permissions(self, service):
         return [p.permission for p in service.permissions]
 
diff --git a/tests/app/service/test_rest.py b/tests/app/service/test_rest.py
index ed2b273d0..7dfaad89a 100644
--- a/tests/app/service/test_rest.py
+++ b/tests/app/service/test_rest.py
@@ -139,6 +139,7 @@ def test_get_service_by_id(admin_request, sample_service):
     assert json_resp['data']['dvla_organisation'] == '001'
     assert json_resp['data']['prefix_sms'] is True
     assert json_resp['data']['postage'] == 'second'
+    assert json_resp['data']['letter_logo_filename'] == 'hm-government'
 
 
 @pytest.mark.parametrize('detailed', [True, False])