The possible reasons for this situation are:

1. The card status is abnormal, such as degaussing, inactivity, too many password locks and expired card. It is recommended to call the bank's customer service hotline to confirm.

2. There is nothing wrong with the card, but the signal of the POS machine is not good. Failure to connect to the network will also lead to card swiping failure.

3. If the cardholder holds an IC chip credit card, because UnionPay has turned off the downgrade transaction function, if the cashier still operates the transaction by swiping the card instead of inserting the card, it will not be available.

Matters needing attention in credit card consumption are:

1. Please check whether the amount on the purchase order is consistent with your consumption amount. Ask questions in time, check the accounts in time, and report the problems to the bank in time.

2. Please don't let others see the password you entered;

3. Please ensure that your signature on the purchase order is consistent with the signature on the back of the card;

4. The shopping receipt is the proof of your credit card consumption, please keep it properly.

Precursor of China Merchants Bank's Credit Card Seal:

Before China Merchants Bank's credit card is blocked, China Merchants Bank will generally send a text message to remind customers. The content of the text message will generally be: "Mr./Ms. XX, due to risk factors, your China Merchants Bank credit card account will be deactivated within 24 hours. Please call for advice? " . Sometimes the staff of China Merchants Bank will call the cardholder directly and tell him that his card is about to be blocked.

If customers are always reminded of risks when using CMB credit card for transaction payment, it may also indicate that their credit card account will be subject to risk control of CMB, and then the card is likely to be deactivated.

It is suggested that customers should pay attention to maintaining good card use behavior at ordinary times, do not swipe their cards on informal POS machines, do not always swipe their cards during non-business hours of merchants, and do not always swipe their cards in integer amounts. Because these may lead to an increase in account risk, banks carry out risk control. Also, after spending by credit card, you must remember to repay on time within the prescribed repayment period to avoid long-term overdue debts.