diff --git a/accounting/recharge.py b/accounting/recharge.py
index 5181cb1..1034f95 100644
--- a/accounting/recharge.py
+++ b/accounting/recharge.py
@@ -47,6 +47,8 @@ class RechargeBiz(PFBiz):
 			return '0'
 		if role == 'customer':
 			return  self.customerid
+		if role is None or role == 'null':
+			return None
 		e = Exception(f'unknown role({role})')
 		exception(f'Exception:{e}')
 		raise e