If you swipe your credit card in a physical store, you don't need to enter the security code. If online payment requires a security code, the security code (CVV code) is on the back of the card, and the 7 digits and the last 3 digits of the magnetic stripe part are security codes.

If the input is wrong, it may be that the card status is abnormal, so you need to contact the credit card customer service phone to verify the card status. Check whether other information is filled in correctly. If the security code is displayed incorrectly, you may have filled in the wrong card number, expiration date or cvv2. Be careful not to fill in the year and month backwards. Once the credit card security code is entered incorrectly for many times, the credit card will be frozen, and you need to call the customer service phone on the back of the card to cancel it, otherwise the card will not be able to conduct online transactions.