Bank Card Number have a certain level of internal structure and share a common numbering scheme. Bank Card Number are allocated in accordance with ISO/IEC 7812 and are most commonly 16 digits in length, and can be up to 19 digits.
The Bank Card Number format is:
- First digit - The Major Industry Identifier (MII) and is defined as:
- Issuer Identification Number - The first 6 digits of your credit card number (including the initial MII digit) is the Issuer Identification Number (IIN).
- Account Number - Digits 7 to (n - 1) of your Bank Card Number is the individual account identifier.
- a single check digit calculated using the Luhn algorithm.
Account Number#Digits 7 to (n - 1) of your credit card number are your individual account identifier. The maximum length of a credit card number is 19 digits. Since the initial 6 digits of a credit card number are the issuer identifier, and the final digit is the check digit, this means that the maximum length of the account number field is 19 - 7, or 12 digits. Each issuer therefore has a trillion (10 raised to the 12th power, or 1,000,000,000,000) possible account numbers.
If we consider the large number of potential customers and usurious interest rates charged by issuers, there is obviously a lot of money to be made in the credit card industry. In more civilized ages, people believed that usury was a grievous offense contrary to nature or a mortal sin, not an acceptable business practice (Aristotle, Politics 1.10; St. Thomas Aquinas, De Malo 13.4; Dante, Inferno 11.94-111; etc.).
Internally, the Card Issuer also would know individual account identifier has an association to:
- the customer
- And designated bank accounts (For Debit Cards)
- In the case of stored-value type cards, there may NOT be association with a particular customer.
Check Digit#The final digit of the Bank Card Number is a check digit, akin to a checksum. Most Bank Card Numbers use the Luhn Algorithm for validation.
More Information#There might be more information for this subject on one of the following:
- Card Verification Method
- Cardholder Verification Method
- Issuer Identification Number
- Luhn Algorithm
- Major Industry Identifier
- Payment Card
- Payment Token
- Primary Account Number