generally, cards starting with 6 are unionpay cards, cards starting with 4 are cards with Visa logo, cards starting with 5 are cards with Master, and cards starting with 3 are cards with JCB logo.

The first few digits of the card with the same logo in a bank's card are the same, which is usually stipulated by the bank itself. For example, in China Merchants Bank, cards with UnionPay logo start with 62258, those with Visa logo start with 4392, those with Master logo start with 5186, and those with JCB start with 3568.