Understanding the First Digits of a Visa Card: BIN and IIN Explained
The first four digits of a Visa card are typically 4, followed by three additional digits that can vary. These digits are part of a larger 16- or 19-digit number that follows a standardized system governed by the International Organization for Standardization (ISO 7812). This standardization ensures that different card types can be easily identified through their unique numeric prefixes. Understanding the structure of these numbers can provide valuable insights into the network and the issuing bank.
The Major Industry Identifier (MII): Network Identification
The first or first two digits of a payment card number are known as the Major Industry Identifier (MII). This identifier serves as a network identifier and indicates which type of network the card belongs to. For Visa cards, the MII is 4. Similarly, MasterCard cards begin with 5, American Express cards start with 34 or 37, and Discover cards begin with 6011.
The MII was named as such because the numbers 3, 4, 5, and 1 were assigned to represent different industries: Travel Entertainment, Bank Financial Services, Bank Financial Services, and Airline Industry, respectively. The digit 6 is reserved for Bank Financial Services, and 2 for Bank Financial Services as well, but these are less commonly used than 5 and 37, 34.
Bank Identification Number (BIN) and Institution Identification Number (IIN)
The first 6 to 9 digits of a payment card number are known as the Bank Identification Number (BIN). However, in more recent usage, these digits are often referred to as the Institution Identification Number (IIN). This number is assigned by Visa and other payment networks to identify the issuing bank and the type of card for transaction processing, billing, and reporting purposes.
For a typical 16-digit Visa card, the first 6 digits form the BIN. In the case of a 19-digit card, the first 8 digits would form the IIN. This system helps in directing transactions to the correct issuing bank and allows for the appropriate card type to be processed.
To gain more detailed information and insights into the structure of payment card numbers, you can refer to the Wikipedia page on payment card numbers.
Conclusion
Understanding the numerical structure of a Visa card, particularly the first four digits as well as the BIN or IIN, can provide important insights into the network and issuing bank of the card. Whether you are a business trying to process payments or a consumer looking to identify a card's issuing bank, knowing these details can be invaluable. For more detailed information, visit the relevant sections on Wikipedia.