Credit card check digits

The credit card check digits are a security measure for paying through the internet. These digits are only printed on the credit card. There are not saved in the magnetic strip. The credit card issuer claim this check number on every transaction through the internet, by phone or by mail. You can find the check digits as follows: Eurocard / Mastercard: The check number has three digits and is placed on the back side of the card short above the signiture field right behind the credit card number. Eurocard call this number CVC2 (Card Verification Code 2). VISA: The check number has also three digits and is placed also on the back side of the card right behind the last for digits of the card number. VISA call this number CVV2 (Card Verification Value 2). American Express: In contrast the check number at an American Express card has four digits and is placed on the front side of the card. It is printed on the right hand side in the middle of the card. American Express call this number 4DBC (4 Digit Batch Code).