kortanúmer

Kortanúmer refers to a unique identifier assigned to a payment card, such as a credit card or debit card. This number is typically a sequence of 16 digits, although some card types may have a different length. The primary purpose of the kortanúmer is to distinguish one card from another, facilitating transactions and ensuring that funds are directed to the correct account.

The structure of a kortanúmer often follows specific conventions. The first digit usually indicates the issuer network, like Visa or Mastercard. Subsequent digits may include information about the issuing bank and the specific account holder. The final digit is often a check digit, calculated using an algorithm such as the Luhn algorithm, which helps to detect errors in the number.

When making a purchase, the kortanúmer is a crucial piece of information provided to the merchant. Along with the expiration date and the security code (CVV/CVC), it is used to authorize the transaction. Security measures are in place to protect this sensitive data from unauthorized access. While the kortanúmer is essential for processing payments, it should be handled with care to prevent fraud. It is not the same as a PIN, which is used for in-person verification.