There are many reasons. The most common one is whether you frequently swipe or pay online.

If your card is blocked by the bank, ask yourself whether you frequently swipe large amounts or pay online in a certain place, that is, whether it is defined as cashing out. The machine where the card is used for consumption happens to have been listed as a risk customer. If the card cannot be swiped on this machine, there may not be a problem with other machines. This card swiping machine has been listed as a risk by one bank, and it may not necessarily have been listed as a risk by other banks. It exceeds the limit stipulated by the bank, or you may have made installments and occupied the limit.

If the credit card is overdue for more than 30 days, the China Construction Bank system will automatically control the credit limit of the card, and only 50% of the credit limit can be used temporarily. If it exceeds 60 days, the card cannot be used temporarily. If it exceeds 90 days, the card will be forcibly suspended and all accounts under your name will be frozen.