If it is a CMB card, you can cancel it at any counter of CMB. When you close the account, you need to swipe your card and verify the withdrawal password, and at the same time close the corresponding functions of the one-card card to successfully close the account. If your one-card has applied for online banking professional edition (UKEY), and there is only a current sub-account in the card and no other functions are enabled, you can also try to cancel it through online banking professional edition.