diff --git a/nova/conductor/manager.py b/nova/conductor/manager.py
index d1615c629d9d..9b4e87ba933f 100644
--- a/nova/conductor/manager.py
+++ b/nova/conductor/manager.py
@@ -1237,13 +1237,6 @@ class ComputeTaskManager(base.Base):
                                               'build_instances', updates, exc,
                                               legacy_spec)
 
-            # TODO(mnaser): The cell mapping should already be populated by
-            #               this point to avoid setting it below here.
-            inst_mapping = objects.InstanceMapping.get_by_instance_uuid(
-                context, instance.uuid)
-            inst_mapping.cell_mapping = cell
-            inst_mapping.save()
-
             # In order to properly clean-up volumes when deleting a server in
             # ERROR status with no host, we need to store BDMs in the same
             # cell.
@@ -1259,6 +1252,18 @@ class ComputeTaskManager(base.Base):
                 with nova_context.target_cell(context, cell) as cctxt:
                     self._create_tags(cctxt, instance.uuid, tags)
 
+            # NOTE(mdbooth): To avoid an incomplete instance record being
+            #                returned by the API, the instance mapping must be
+            #                created after the instance record is complete in
+            #                the cell, and before the build request is
+            #                destroyed.
+            # TODO(mnaser): The cell mapping should already be populated by
+            #               this point to avoid setting it below here.
+            inst_mapping = objects.InstanceMapping.get_by_instance_uuid(
+                context, instance.uuid)
+            inst_mapping.cell_mapping = cell
+            inst_mapping.save()
+
             # Be paranoid about artifacts being deleted underneath us.
             try:
                 build_request.destroy()
diff --git a/nova/tests/unit/conductor/test_conductor.py b/nova/tests/unit/conductor/test_conductor.py
index 26fd651375a4..b3cfc70bcc07 100644
--- a/nova/tests/unit/conductor/test_conductor.py
+++ b/nova/tests/unit/conductor/test_conductor.py
@@ -1912,6 +1912,61 @@ class ConductorTaskTestCase(_BaseTaskTestCase, test_compute.BaseTestCase):
 
         self.assertTrue(mock_build.called)
 
+    @mock.patch('nova.objects.InstanceMapping.get_by_instance_uuid')
+    def test_cleanup_build_artifacts(self, inst_map_get):
+        """Simple test to ensure the order of operations in the cleanup method
+        is enforced.
+        """
+        req_spec = fake_request_spec.fake_spec_obj()
+        build_req = fake_build_request.fake_req_obj(self.context)
+        instance = build_req.instance
+        bdms = objects.BlockDeviceMappingList(objects=[
+            objects.BlockDeviceMapping(instance_uuid=instance.uuid)])
+        tags = objects.TagList(objects=[objects.Tag(tag='test')])
+        cell1 = self.cell_mappings['cell1']
+        cell_mapping_cache = {instance.uuid: cell1}
+        err = exc.TooManyInstances('test')
+
+        # We need to assert that BDMs and tags are created in the cell DB
+        # before the instance mapping is updated.
+        def fake_create_block_device_mapping(*args, **kwargs):
+            inst_map_get.return_value.save.assert_not_called()
+
+        def fake_create_tags(*args, **kwargs):
+            inst_map_get.return_value.save.assert_not_called()
+
+        with test.nested(
+            mock.patch.object(self.conductor_manager,
+                              '_set_vm_state_and_notify'),
+            mock.patch.object(self.conductor_manager,
+                              '_create_block_device_mapping',
+                              side_effect=fake_create_block_device_mapping),
+            mock.patch.object(self.conductor_manager, '_create_tags',
+                              side_effect=fake_create_tags),
+            mock.patch.object(build_req, 'destroy'),
+            mock.patch.object(req_spec, 'destroy'),
+        ) as (
+            _set_vm_state_and_notify, _create_block_device_mapping,
+            _create_tags, build_req_destroy, req_spec_destroy,
+        ):
+            self.conductor_manager._cleanup_build_artifacts(
+                self.context, err, [instance], [build_req], [req_spec], bdms,
+                tags, cell_mapping_cache)
+        # Assert the various mock calls.
+        _set_vm_state_and_notify.assert_called_once_with(
+            test.MatchType(context.RequestContext), instance.uuid,
+            'build_instances',
+            {'vm_state': vm_states.ERROR, 'task_state': None}, err,
+            req_spec.to_legacy_request_spec_dict())
+        _create_block_device_mapping.assert_called_once_with(
+            cell1, instance.flavor, instance.uuid, bdms)
+        _create_tags.assert_called_once_with(
+            test.MatchType(context.RequestContext), instance.uuid, tags)
+        inst_map_get.return_value.save.assert_called_once_with()
+        self.assertEqual(cell1, inst_map_get.return_value.cell_mapping)
+        build_req_destroy.assert_called_once_with()
+        req_spec_destroy.assert_called_once_with()
+
     @mock.patch('nova.objects.CellMapping.get_by_uuid')
     def test_bury_in_cell0_no_cell0(self, mock_cm_get):
         mock_cm_get.side_effect = exc.CellMappingNotFound(uuid='0')