1. The security code of a credit card refers to the last three digits of the signature field on the back of the credit card. Mastercard is called CardValidation Code (CVC). VISACVV and MC CVC are both 3-digit or 4-digit numbers generated from the card number, validity period and service constraint code. They are generally written in the 2-track user-defined data area of ??the card's magnetic stripe. The generation methods of CVV ??and CVC are the same. CVV2 is a number printed in the signature area of ??the Visa/MasterCard card. It is located in the 3 digits after the credit card number. The last three digits we usually see on the back of credit cards are actually CVV2, not the CVV code.

2. The last three digits of the credit card must not be disclosed to others. On most foreign websites, when paying with a credit card, you only need to enter the credit card number and the security code on the back of the credit card to successfully pay. As soon as someone asks you for photos of the front and back of your credit card, please call the police immediately. This is credit card fraud. Please protect your personal credit card information and do not disclose it to others.