VISA, MASTERCARD & DISCOVER credit cards have a three-digit (cvv) number. It is printed in the signature panel on the back of the Visa, MasterCard and Discover cards. The verification number is the last 3 digits on the right side of the panel. AMERICAN EXPRESS credit cards have a 4 digit non-embossed number. It is printed above the account number on the front of your card. It may appear to the left or the the right, but it is always above your account number.