It depends on whether it is necessary, but the amount of the secondary card is shared with the main card. If it is not necessary, don't open the card, because the supplementary card also charges an annual fee.

The relationship between the primary card and the secondary card of China Merchants Bank;

All debts incurred by the supplementary cardholder when using the credit card shall be borne by the main cardholder, and the main cardholder shall directly perform the debts to the card issuer or special unit. The primary card and the secondary card belong to the same account and share the credit line. Most of the cardholders of the main card and the deputy card have a common property relationship, or know and trust each other, and there are agreements such as gift, entrustment and paid commitment between them.

In the relationship between the principal cardholder and the secondary cardholder, the principal cardholder is in a dominant position, and the principal cardholder has the right to decide to add or cancel the secondary cardholder, while the secondary cardholder is in a subordinate position. If the primary card is cancelled, the secondary card should be returned to the card issuer voluntarily. When the main cardholder requests to stop using the supplementary card midway, he should also return the supplementary card to the card issuer. If there is any outstanding debt, the debt will still be borne by the main cardholder.

In short, the principal cardholder has all the rights to supervise, use or stop all the items enjoyed by the deputy cardholder. The main card is closely related to the sub-card, and it is responsible for the risk of arrears caused by the sub-card.