Both the main credit card and the subsidiary credit card issued by ABC support the basic functions of credit cards, namely, credit card overdraft consumption function, credit card overdraft cash withdrawal function, credit card installment payment function and so on. However, ABC's main credit card can exist alone, and the subsidiary credit card of the bank, as its name implies, must be based on the existence of the main credit card before applying.

Two credit cards share the credit line of the same credit card account, and the transaction is recorded in the same bill, and the presiding cardholder assumes the responsibility of credit card repayment. Under normal circumstances, the personal points accumulated by supplementary card transactions belong to the main card account, and supplementary card holders may not apply for credit card withdrawal.

As for the application method, it is nothing more than a free application through the formal online and offline channels provided by ABC.