When you try to operate the credit card business in CCB's online banking, there are usually three possible reasons for the prompt that "the account number does not exist": First, the card number you entered may be wrong. The credit card of CCB is 16 digits, and the savings card is 19 digits. Please confirm whether it is entered correctly. Secondly, confirm whether the card selection is accurate. This will also happen if you choose a savings card but actually enter a credit card. Finally, if the card has been cancelled or reported lost, the system will naturally be unable to find your card information, prompting that the account number does not exist.

in order to solve the problem, it is suggested to investigate these three possibilities one by one. If all the above are confirmed, you may need to contact the bank's customer service for professional help.

with regard to the use of credit cards, it is worth noting that with the development of science and technology, security issues have become increasingly prominent. The following are several aspects that credit card security should pay attention to: avoid fraudulent use of fake or invalid cards and protect personal information from being stolen. Keep and handle expired or invalid credit cards properly to ensure information security. Be wary of merchant fraud, whether it is entity or network, we must ensure the safety of consumption. Be alert to possible internal security risks of card issuers, such as information leakage or illegal operation by internal personnel. Finally, even the most advanced trading system may be attacked, so always be vigilant.

The above information is referenced from the FAQ of China Construction Bank.