The last three digits on the back of the credit card are the credit card security code. The security code is equivalent to the credit card’s ID card. The cardholder can use the security code to make cardless purchases. The security code of visa and MasterCard is called CVV2; The security code of Discover card and American Express card is called CID; the security code of UnionPay card is called CVN2; the security code of JCB card is called CAV2.

The security code information is stored in the magnetic stripe of the credit card and is technically encrypted by the card-issuing bank. Since different banks have different encryption algorithms, illegally produced credit card banks can easily identify them.

A credit card is a credit certificate issued by a commercial bank or credit card company to consumers with qualified credit. Consumers holding credit cards can enjoy the shopping method of spending first and repaying later, and cardholders can overdraft within the specified amount. The name of the card issuer, validity period, number, cardholder name, etc. are printed on the front of the credit card. The chip, magnetic strip and signature strip are designed on the back of the credit card.

Credit cards are divided into credit cards and quasi-credit cards. A credit card refers to a credit card with a certain credit limit, and users can consume within the limit and then repay. A quasi-credit card requires a certain amount of reserve fund to be deposited. When the reserve fund is insufficient to cover the payment, a credit card can be overdrawn within the credit limit. Common references to credit cards usually refer to credit cards.

There are four ways to check the credit card balance. First, the user can bring the credit card to the ATM machine to check, insert the card into the ATM machine and enter the password, and click the query to display the balance. The second is to go to the bank counter in person with your credit card and ID card to make inquiries. The third is to call the bank’s customer service number and check the credit card balance through manual service. The fourth is to open the official website of the credit card, log in to your online banking account, and check the credit card balance in the account information.

Generally speaking, the application for a credit card requires the applicant to have a certain source of income and full capacity for civil conduct (a citizen of mainland China who is over 18 years old). The card-issuing bank receives the application form submitted by the applicant. After collecting relevant materials, the applicant’s credit status should be reviewed, including the applicant’s assets, the applicant’s repayment ability, and the applicant’s source of income. In addition, the credit card can only be used by yourself, lending it to others is a violation of the usage contract.