Debit card is basically an ATM card issued by banks to allow the customers to withdraw money from ATM vending machines and facilitate online banking. The first digit represents the Industry code and is the Major Industry Identifier (MII). The first six digits form the Issuer Identification Number (IIN). The seventh to fifteenth digits are linked to one's bank account number though they do not reveal anything about the user's account directly. The last digit is known as the check digit that checks and confirms the validity of the card.