- The very first digit of a bank card number is called the major industry identifier and it identifies the type of credit card. American Express cards start with a 3, Visa cards start with a 4, MasterCard cards start with a 5, and Discover cards start with a 6. Certain airline credit cards start with a 1 or 2, certain petroleum company cards start with a 7 and certain telecommunications and healthcare cards start with an 8.
- The first six digits of a bank card number identify the credit card network associated with the card, such as 601100 for Discover cards.
- The last digit of a bank card number is a checksum number, which helps prevent criminals from creating fraudulent credit card numbers.
- The numbers in between the first six digits and the last digit is a primary account number (PAN), It uniquely identify the customer’s account.