The bank card is missing three digits, and the account number is 16 digits, which may be a credit card or quasi-credit card. The three digits behind the credit card are the three digits behind the credit card, which is called "the last three digits". The last three digits of the signature column on the back of the credit card are the verification code of the transaction password without a card, which is used by the cardholder to verify his identity when making consumption without a card. It should be reminded that once the cardholder discloses these three figures, it is easy to cause the amount in the card to be stolen. The last three digits are the verification code (also called "the last three digits"), which is the most useful for online transactions. The verification code of credit card is called CVV code. It is a 3-digit string generated by the card number, validity period and service constraint code through the coding rules and encryption algorithm of the issuing bank. China Construction Bank app Android VersionNo.: V5.0.3; ; Apple version number: v5.4. 1.

1. I forgot how to check the bank card number: Bank client query: Make sure that the bank client is installed on the mobile phone, click Login, click Login on Pocket Bank after logging in, and fill in the mobile phone number and login password reserved by the bank. After logging in, select the query service and click Open. Select Registered Account Query under Query Service, and then click Open. Click Simplify Code, and then click Expand. The new page is the card number of the bank card, full code, which can be filled in as needed. The method of checking the card numbers of different bank cards is similar. The key is to find the registered account information. For account security reasons, at present, the bank card information in Alipay account can only be viewed to the last 4 digits of the tail number, and the complete card number information cannot be viewed. Please log in to Alipay account and click Alipay-Account Management-Bank Card to view the bank account information bound to Alipay account. Business hall inquiry: I hold my ID card to the relevant bank to inquire about my bank account information; Customer service inquiry: use your mobile phone number reserved in the bank to call the customer service of the bank, then transfer it to the manual service, quote the ID number registered when you apply for the card and inquire the bank card number.

2. There are many situations in which construction bank cards are frozen: cardholders commit crimes, credit cards are cashed out, credit cards are overdue seriously, and credit cards are stolen. The first case is special, and the parties can only consult the Construction Bank after the penalty time is over; In the second case, due to the freezing of credit card cashing, there are several situations. If you cash out subjectively, you need to wait for the bank to cash out. If you don't cash out subjectively, you can go to the bank to apply for credit card unfreezing or call the credit card customer service center of the issuing bank to explain the situation and apply for unfreezing; In the third case, because the credit card is frozen due to overdue, the cardholder should repay the overdue amount as soon as possible and call the credit card customer service center of the issuing bank as soon as possible to explain the situation; In the fourth case, because the stolen credit card is frozen, CCB can only unfreeze it after the stolen credit card is processed.