CSC stands for card-security code. This security code located either on the front or back of debit and credit cards, depending on what type of card it is. This security code is officially known as a CID (Card Identification Number) on American Express cards. You may need to enter the card-security code when making online purchases. As long as you have your debit or credit card in front of you, locating the number is simple.
Examine the card closely. If the front says "Visa," "Mastercard" or "Discover," then the CSC code is located on the back of the card. If the front says "Amex" or "American Express," then the CSC code is located on the front part of the card.
Flip the card over to view the back if it is a Visa, Mastercard or Discover card. Look on the right side of the card directly beneath the magnetic bar strip. You will see a three-digit code. This is your CSC code.
Examine the front of the card if it is an American Express card. You will see a set of four digits on the right side of the card, directly above the last digits of the card. This four-digit number is your CSC card.