diff --git a/lib/partner.js b/lib/partner.js
index 043552e..d31cf57 100644
--- a/lib/partner.js
+++ b/lib/partner.js
@@ -95,7 +95,7 @@ function _topUpRequest(task, isAdvice) {
             trx_id: task.trx_id,
             rc: partnerRc[value[RESPONSECODE_TAG]] || '40',
             message: stringify(value),
-            sn: (value.SN || '').replace(/;$/, '') || st24.extractSnFromMessage(value.MESSAGE),
+            sn: (value.SN || '').replace(/;$/, '') || st24.extractSnFromMessage(value.MESSAGE, config.sn_pattern),
             amount: value.PRICE || st24.extractPriceFromMsg(value.MESSAGE),
             raw: value,
             misc: {