The current 16-digit credit card number is an international standard, and the first 6 digits are BIN, which is allocated by international card organizations. The first four digits of the credit card number are VISA cards and the fifth is Master. 622126~622925 are UnionPay standard cards. 6 starts with China UnionPay single currency card (or American discover), credit card number 4 starts with international brand VISA credit card (the world's first credit card organization), 5 starts with international brand MASTERCARD, and 3 starts with Japanese JCB and AMERICAN EXPRESS. The 7th-15th rows are allocated according to their own needs, and the 16th is the parity bit. Other non-16-digit card numbers are assigned by banks themselves.

the credit card number is a protruding 16-digit number on the front, which is located below one-third of the card. Under the card number, the period of validity is separated by a "/"symbol, and at the bottom is the cardholder's name. As shown in the figure below: