The reason why the credit card of China Bank needs to be mailed to the branch when it expires is to ensure the safety and timeliness of sending the credit card. According to the relevant public information, in order to avoid the risk of loss or misappropriation of credit cards in the postal process, China Bank will send the credit cards to the branch where the cardholders are located, and the cardholders will go to the branch to collect them. This can ensure the security of the credit card, and at the same time, it can remind the cardholder to change the card in time, so as not to affect the use of the credit card because it is not changed in time.