Card Security Code

The CSC, also known as the Card Security Code, is a numeric code consisting of three or four digits that is printed (not embossed) on a credit card. Its purpose is to prove that the person making a transaction with the card physically possesses the card.

Initially introduced by Equifax in the late 1990s, CSCs were developed to enhance security measures in the emerging field of e-commerce. Subsequently, all major credit card networks adopted the concept, albeit with slight variations in implementation.

Discover, Mastercard, and Visa utilize a three-digit CSC printed on the back of the card. On the other hand, American Express employs a four-digit CSC located on the card’s front. Moreover, each card network uses a distinct term to denote its respective CSC:

• American Express: Card Identification Number
• Discover: Card Security Code
• Mastercard: Card Validation Code 2
• Visa: Card Verification Value 2

Both Mastercard and Visa employ the numeral “2” to signify the CSC printed on the back of their cards. This distinction is essential to differentiate it from similar codes encoded in the magnetic stripe, primarily used to validate transactions conducted with the physical presence of the card.

The presence of the CSC on credit cards serves as an additional layer of security for both the cardholder and the issuing banks. Requiring the cardholder to provide the CSC during online transactions helps verify their identity and deters fraudulent activities. In case of a dispute or unauthorized transaction, the CSC can also play a crucial role in the chargeback process. The cardholder can provide the CSC as evidence to support their claim and assist the issuing bank in effectively investigating and resolving the dispute. This collaboration between the cardholder, the CSC, and the chargeback mechanism maintains the integrity of electronic payments and safeguards the interests of all parties involved.