The security code is a special kind of code used to prevent the illegal use of credit and debit cards. Please verify below where the code can be found in each credit card. For VISA, MasterCard, JCB and Diners Club, the code is a three-digit number written in the back of the credit card (it is located immediately on the right of the main card number) For American Express, it is the four-digit number written on the front of the credit card (it is located on the upper right of the main card number) If you are unable to locate the security code, or if it is illegible, please contact either the bank written on the card or the credit card company. In case you are unable to solve your problem even after reading the instructions above, please contact us through the form below.