When swiping a card, the cardholder receives a short message but the machine does not print a receipt, which is called a "unilateral account", which is an invalid transaction and must be reconfirmed:

1. Use the "Print Last Pen" function of the machine immediately. If it is, it means that the transaction is successful; if it is not, it means that the transaction has failed;

2. Use any bank card to test the credit card for a few cents. If the machine shows "reverse", the transaction just now is a failure;

3. The cardholder's short message cannot be used as evidence of the merchant's deduction, and the only evidence is the transaction receipt;

4. At this time, you must swipe your card again, and both parties should keep contact information with each other. Don't tell the cardholder to go away, otherwise it is extremely difficult for the merchant to find the cardholder, but the cardholder has the right to find the merchant.

5. Another way is that the merchant immediately logs into the POS merchant background to check the real-time status of the transaction.