What happened to cause the duplicate charge? #

• When two servers try to settle the same order at the same time.
• When a server sends a payment request to the wrong credit card terminal, and another server, unaware of it, inserts the credit card into that terminal. Meanwhile, the first server sends the request again to another credit card terminal.
• When a server processes a payment, but due to network lag, the system does not receive the payment result in time, causing the server to initiate another payment.

Preventing Duplicate Payments #

• When two payment requests are made for the same order, the system will display the following prompt:
  1. Cancel – Cancels the new payment request.
  2. Confirm – Continues the payment request (Only proceed if you are sure the first request was canceled; otherwise, this may cause a duplicate charge).
• If duplicate payments occur, the system will display a negative “Amount Due”, and all devices will receive a duplicate payment notification. Click here to learn how to find and Refund Duplicate Credit Card Charges.