The mother-child card we often refer to is the bank’s primary and secondary cards. The supplementary card function of a credit card is the same as that of the main card. It can withdraw cash and make purchases, and it also charges an annual fee. Taking ICBC as an example, when applying for a credit card, the main card applicant can apply for no more than two supplementary cards for his spouse, parents or children who have full capacity for civil conduct. The main card holder is obliged to urge the supplementary card holder to The cardholder abides by the Peony Credit Card Articles and the relevant provisions of this contract, and shall bear all losses caused by the supplementary cardholder's violation of relevant provisions. The primary card applicant has the right to apply to cancel the secondary card or stop using the secondary card at any time, and must bear all debts incurred under the secondary card. If you use the secondary card to withdraw cash, the primary card must bear the repayment obligation.

Generally speaking, the annual fee for the supplementary card is 50 yuan for the main card. For example, the annual fee for the main card of Shanghai Pudong Development Bank's ordinary credit card is 180 yuan, so the annual fee for the supplementary card for this credit card is 90 yuan. The annual fee exemption policy for the supplementary card is the same as that for the main card. For example, a certain bank's credit card requires 6 purchases per year to be exempted from the annual fee for the following year. If you hold both the bank's main credit card and the main card, As for the supplementary card, if the main card does not make more than 6 purchases per year, then in addition to the 180 yuan annual fee for the main card, you will also have to pay the 90 yuan annual fee for the supplementary card. From this point of view, once you hold a primary and secondary credit card, you must first ensure that the primary card consumption meets the annual fee-free conditions, otherwise the gain will outweigh the loss.