diff --git a/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java b/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
index 714b864d4..78d2c8d62 100644
--- a/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
+++ b/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
@@ -268,7 +268,7 @@ public class SimpleClientApplyServiceImpl implements SimpleClientApplyService {
         JSONObject sysConfig = sysConfigManager.getSysConfig();
 
         String arr [] = sysConfig.getString("temp_sub_mch_id").split(",");
-        String tempSubMerchantId  = arr[new Random().nextInt(arr.length) + 1];
+        String tempSubMerchantId  = arr[new Random().nextInt(arr.length)];
         WeChatPayConfig.Merchant availableMerchant = mpPaymentApi.determineMerchant(tempSubMerchantId);
         String clientMoniker = generateClientMoniker();
         JSONObject sysClient = new JSONObject();