External cards are bank cards issued outside China (including Hong Kong, Macao and Taiwan). All domestic credit cards have the "UnionPay" logo in addition to the VISA or MASTER logo. Foreign credit cards No, because UnionPay is the only Chinese bank card organization established in China with the approval of the State Council and the approval of the People's Bank of China.

If you just use the number, most people can't find it. They can only tell what card it is. There are only four institutions in the world that can issue credit cards, namely VISA and MASTER, which we most often come into contact with, and the less common Diners Club and American Express.

First of all, it is distinguished by the number of digits in the card number. VISA and MASTER card numbers have 16 digits, Diners Club has 15 digits, and American Express has only 14 digits. So how to distinguish VISA and MASTER? VISA cards all start with 4 characters, and MASTER cards all start with 5 characters. This is the same whether it is domestic or overseas, so you can only distinguish the card type by the card number, but you cannot distinguish between domestic and foreign cards.

The credit card prompt is not a foreign card number: it is possible that your credit card is a "UnionPay single currency card", because the credit cards issued by this bank have the function of dual currency cards, which means that they can be used domestically and also Can be used as foreign currency abroad.