The old card can be directly cut off or kept by itself when it is confirmed that there is no debt. It has the information of the cardholder. If it is picked up by the bad guys, it may be stolen. If this card still has arrears, such as annual fees, it needs to be returned in time.

If you need to apply for a new credit card, the bank will mail you a new card, and if you don't want to continue using it, you can cancel it.