diff --git a/src/cloudforet/cost_analysis/manager/cost_manager.py b/src/cloudforet/cost_analysis/manager/cost_manager.py
index a58c33a..159f0b7 100644
--- a/src/cloudforet/cost_analysis/manager/cost_manager.py
+++ b/src/cloudforet/cost_analysis/manager/cost_manager.py
@@ -182,7 +182,7 @@ def _get_tenant_ids(task_options, collect_scope):
         if 'tenant_id' in task_options:
             tenant_ids.append(task_options['tenant_id'])
         elif collect_scope == 'customer_tenant_id':
-            tenant_ids.append(task_options['customer_tenants'])
+            tenant_ids.extend(task_options['customer_tenants'])
         else:
             tenant_ids.append('EA Agreement')
         return tenant_ids