What Is an Issuer Identification Number (IIN)?

An Issuer Identification Number (IIN) is a crucial element on payment cards that identifies the issuing financial institution responsible for the card. These numbers are present on various payment cards globally, including credit, debit, and others, and are alternatively known as Bank Identification Numbers (BINs).

Key Takeaways

• Issuer Identification Numbers (IIN) signify the financial institution that issued a specific credit or debit card and its associated card processing network (such as Visa or Mastercard).
• The IIN typically appears as the initial set of digits in the card number.
• Following the IIN, there are unique digits for the cardholder, culminating in a “check digit” for authentication.
• IINs usually comprise six or eight digits, while a complete card number may extend to 19 digits.

Understanding Issuer Identification Numbers

Credit card numbers vary in length, often ranging from 15 to 16 digits, with the first six to eight digits representing the IIN.

The initial digit is the Major Industry Identifier (MII) number established by the International Organization for Standardization (ISO) and the International Electrotechnical Commission in the ISO/IEC 7812 standard.

MII numbers associate with specific industries; for instance, 3, 4, 5, and 6 relate to banking and finance, while 1 and 2 are for airlines.

Notably, distinctive credit card prefixes include 4 for Visa, 2 or 5 for Mastercard, 6 for Discover, and 3 for American Express.

The subsequent five to seven digits in the IIN identify the issuing bank or financial institution, adapting to the rise in card issuance by extending IINs from six to eight digits in recent times.

Following the IIN are unique numbers for the cardholder, with the final “check digit” confirming the card’s authenticity through the Luhn Algorithm.

These numbers collectively form the Primary Account Number (PAN), encompassing details of the card network, issuing institution, and cardholder.

1 Quadrillion: That’s the potential combinations from a standard 15- or 16-digit credit card, providing immense variability for card numbers.

The Importance of Issuer Identification Numbers

Issuer Identification Numbers, together with corresponding account numbers, enable quick verification of card validity and fund availability, essential for swift transaction processing.

Credit Card Numbers vs. Account Numbers

Credit card numbers differ from account numbers, with account numbers staying consistent even if the card is replaced due to loss or theft, emphasizing the importance of safeguarding account details.

What Is a CVV Code?

a CVV code, a 3-4 digit value on credit and debit cards, enhances security by requiring physical card possession for online transactions.

Can a Store Print Your Credit Card Number on Your Receipt?

Under FACTA regulations, merchants must limit credit card exposure on receipts by showing only the last five digits, bolstering protection against potential fraud.

What Is a Virtual Credit Card Number?

A Virtual Credit Card Number, distinct from a primary card number but sharing the same account, offers heightened security for online transactions, reducing the risk of identity theft.

Do Authorized Users on a Credit Card Get Their Own Account Number?

Authorized users may receive cards with customized numbers depending on the issuer, yet the primary cardholder remains accountable for all charges incurred by authorized users.

The Bottom Line

Issuer Identification Numbers on payment cards reveal the issuing financial institution and network affiliation, while the remaining card details are unique to the individual cardholder, enhancing card security.