Repay the debt with the main card or the supplementary card; there is no need to pay the debt separately. For the main credit card and the supplementary card, the money consumed will be counted into the main card account. When repaying, both the main card and the supplementary card can be repaid.

All transaction amounts and corresponding interest, fees, etc. of the supplementary card will be credited to the main card account, and the main cardholder shall bear all repayment responsibilities; the main cardholder and the person with full capacity for civil conduct shall Supplementary cardholders are jointly and severally liable for repaying the amounts owed to the bank. Supplementary cardholders with limited capacity for civil conduct are only responsible for repaying debts incurred by the supplementary cards they hold.

Supplementary cards are relative to the main card. Each main cardholder who opens a credit card can apply for an additional card for other natural persons with full capacity for civil conduct, or natural persons with limited capacity for civil conduct who are over 13 years old (applicants for supplementary cards who are under 18 years old must obtain the consent of its legal representative).

Extended information:

Each main credit card can apply for up to two supplementary cards (the bank can stipulate it independently). The main cardholder has the right to request the cancellation of his supplementary cards. The credit limit of the supplementary card is designated by the principal cardholder on the premise that it does not exceed the credit limit of the corresponding principal card; if the principal cardholder does not specify it, the credit limit of the supplementary card is the same as that of the principal card.

All transaction amounts and corresponding interest and fees of the supplementary card will be charged to the main card account, and the main cardholder shall bear all repayment responsibilities. However, the principal cardholder and the supplementary cardholder are jointly and severally liable to each other for repaying the amounts owed.

Reference: Baidu Encyclopedia_Supplementary Card