The number of card numbers of domestic credit cards follows international standards, ranging from 13 digits to 19 digits. Most commonly used credit cards in China are 16 digits, as well as 15 digits of American Express and 14 digits of Dalai.

The first digit of the credit card number can distinguish the card issuer. Generally, the card starting with 6 is UnionPay card, the card starting with 4 is a card with Visa logo, the card starting with 5 is a card with Master logo, and the card starting with 3 is a card with JCB logo.

The first six digits of the credit card number are the BIN code of the bank brand, and the BIN code of the domestic bank is assigned by China UnionPay. For example, the card of China Merchants Bank with the UnionPay logo starts with 62258. In addition, the card numbers of debit cards and credit cards of the same bank are generally different. The credit card is 16 digits and the debit card is 19 digits.