Credit card purchases will use the security code on the back of the card. Especially when doing card-less transactions or overseas transactions, the credit card security code is equivalent to the credit card’s ID card. We can use this code to make purchases. consumer transactions. Shopping on overseas websites does not require a password. As long as the buyer provides an account number and security code, the transaction can be completed. In China, there are also merchants that have signed contracts with banks to complete phone transfers without a credit card password and only with a security code. Therefore, everyone must take good care of their credit cards and keep them out of their sight when making purchases to prevent others from remembering your credit card account number and security code.