1, system maintenance This is a common reason. The payment company is upgraded to improve the docking system with the bank, and the credit card of this bank will not be swiped during the maintenance period.

2. The number of times the merchant swipes the card exceeds the limit. Most of the large POS are self-selected merchants of APP, and the merchants are all in the merchant pool mode. You need to select a merchant on the mobile APP to swipe your card on the POS machine. In order to prevent the abnormal flow of merchants in the merchant pool, the payment company often limits the number of times the merchant swipes the card in one day. In this case, you can change merchants on the APP.

3. Some credit cards restrict transactions. Due to loopholes in the banking system of some credit cards and low risk control ability, payment companies will restrict such cards from trading on pos machines. Another situation is that credit cards restrict transactions. Banks keep introducing new credit cards, and sometimes credit cards will be invalid before the payment company has time to update them.