1. The credit card limit may make it impossible to swipe. For example, the credit card has a daily limit, so if the limit has been reached, even if there is a balance on the card, it cannot be used.

2. If the card is frozen, it may be impossible to swipe the card. For example, if the transaction is suspected to be risky by the bank, it will be frozen by the bank, and even if the user still has the limit, he can't swipe the card. It is necessary to contact the issuing bank to consult the specific reasons for the freeze and further handle it.

3. The password is entered incorrectly. If the wrong transaction password is entered, the card will not be able to conduct any transactions and will not be able to use the limit.

4. There is something wrong with the POS machine. If the credit card is all right and the POS machine is out of order, it may not work.

what are the basic functions of a credit card?

there is no savings interest, and account transfer is not allowed. Generally speaking, credit cards can be consumed first, repaid later, overdrawn within the limit allowed by the issuing bank, and enjoy an interest-free period. The most basic function of credit card is that it can be used for consumption through POS machines installed by merchants or directly on the Internet. Credit cards can be swiped through POS machines installed by merchants or directly consumed online, which is the most basic function of credit cards.