On Visa and MasterCard the three-digit number is located on the signature panel on the back of the card. On American Express the four-digit number is located on the front of the card above the credit card number.
Updated over a year ago
On Visa and MasterCard the three-digit number is located on the signature panel on the back of the card. On American Express the four-digit number is located on the front of the card above the credit card number.