Introduction All you know what information contains in your NIC number. But do you know what information contains in the Credit Card Number? Following article provides brief details about what information contain in your credit card and demonstrates to how to validate credit card number using mod 10 (Luhn) algorithms with C#. Background Card Length Typically, credit card numbers are all numeric and the length of the credit card number is between 12 digits to 19 digits. 14, 15, 16 digits – Diners Club 15 digits – American Express 13, 16 digits – Visa 16 digits - MasterCard For more information please refer http://en.wikipedia.org/wiki/Bank_card_number . Hidden information Major Industry Identifier (MII) The first digit of the credit card number is the Major Industry Identifier (MII). It designates the category of the entry which issued the card. 1 and 2 – Airlin...