How to find your security code
If you flip over your credit card and look at the signature box, you
should see either the entire 16-digit credit card number or just the
last four digits followed by a special 3-digit code. This 3-digit
code is your Card Security Code. Enter this 3-digit code in the box
provided. For American Express, you will see a 4-digit code
on the front of your card at the top right.