There is money stored in bank credit cards that can be withdrawn, but in some cases a certain handling fee is required. The remaining money that a bank card user deposits when repaying the loan or the amount owed in the bank card is called overflow, which is the excess payment.

If there is an overpayment in the bank card, the credit limit of the bank card will be increased, that is, this part of the money will be deducted first when consumption, and the credit limit will be deducted after the overpayment is deducted. When the customer's spending power is lower than the overpayment, the user's credit card will not be overdrawn. Therefore, consumers can directly swipe the balance in their credit card purchases during daily consumption, and they can even use up the money. No interest fees will be incurred until the money is used up.

The emergence of bank cards is to provide more convenience or choice for everyone's consumption, rather than to save money. Therefore, the correct way to use a credit card is to use the card to make purchases and then repay. Most people think that credit cards are the same as ordinary savings cards. They can also make deposits and earn interest. This is a wrong view. Credit cards and debit cards are different.