The credit card security code is a set of 3 or 4 digits on the credit card. Its generation method is that the bank extracts the account number, validity period and service code of the card, arranges them and then calculates them through a series of complicated algorithms. After this set of numbers is generated, only the issuing bank and the holder of the bank card know what this number is.
The red box in the picture is the security code.
Extended data
Credit card loss reporting method
After the credit card is stolen or lost, you should report the loss orally first. Oral loss reporting is temporary loss reporting, mainly by calling the official customer service phone of the bank to which the bank card belongs, or by manual customer service. If you don't know the official customer service telephone number of the bank, you can call 1 14 to inquire first.
It should be noted that the oral loss report is valid for 5 days. On the sixth day, you need to call again to continue to report the loss until you officially report the loss and apply for a new bank card. If you find your bank card after reporting the loss orally, you can take your ID card to any outlet of the issuing bank to decouple it.
To report the loss in the bank, the parties need to bring their ID cards, queue up at the bank to call the number, ask the counter staff to get the application form, and then fill in the contents that must be filled in the customer column above; After calling the station, go to the counter and give the ID card and application form to the counter staff for their inquiry. If you want to reissue it according to the instructions of the counter staff, go home and wait.
References:
Baidu encyclopedia-credit card security code