The most common reasons for displaying invalid merchants by swiping credit cards are: the merchant does not exist, the key of pos machine is lost, the merchant has changed the running card, the merchant of pos machine is blocked, and the payment company system is maintained. After swiping the credit card to show the invalid merchants, it means that the credit card consumption has not been completed normally. We should find out the reason first, and then start to solve it.
The solution is as follows: 1. The credit card is not activated. The cardholder can activate the credit card through the customer service hotline on the back of the card according to the voice prompt. 2. The magnetic stripe of the credit card is worn. If there is no degaussing, you can succeed by trying a few more times. Or go to the counter or ATM to try the brush. If it is confirmed that the magnetic stripe is damaged, call customer service to apply for card copying. 3. The 3.POS line is busy or faulty. You can try again later. 4. The status of the card or account is abnormal, such as overdue, loss reporting, freezing, etc.