1, transaction environment: Credit cards can only be swiped in an environment that supports credit card payment, such as POS machines and merchant codes that enable credit card collection. If you don't support credit card, you can't do it. For example, you can't pay by credit card by scanning personal code. In addition, if the system detects risks, it will not be allowed to brush the machine.

2. Card swiping equipment: If it is a POS machine that swipes a card, if the flow card of the POS machine has no flow, the card cannot be swiped, and the flow card must be replaced; In addition, on the same day, the POS transaction reached the limit, generally between 65438+ 10,000 and 300,000, and it was impossible to swipe the card again. Or the merchant has been blacklisted by the bank.

3. Transaction limit: The available credit card limit shall not be lower than the single transaction limit. Insufficient credit, even if the status is normal, you can't swipe your card; Or the cardholder has set a limit, which cannot be swiped after reaching the limit; There is also a credit card that is risk-controlled by the bank, and the credit card prompts the limit.

4. Trading password: Most people trade by password. However, in the case of flash payment, a single payment does not exceed 1 1,000 yuan, and the password is still required if it exceeds 1 1,000 yuan. If you enter the wrong password when swiping the card, the card will be invalid. If you enter the wrong password three times in a row, the credit card will be locked and must be unlocked before you can swipe it.