ISO/IEC 7812 Identification cards — Identification of issuers was first published by the International Organization for Standardization (ISO) in 1989. It is the international standard that specifies "a numbering system for the identification of issuers of cards that require an issuer identification number (IIN) to operate in international, interindustry and/or intra-industry interchange", and procedures for registering IINs. ISO/IEC 7812 has two parts:
- Part 1: Numbering system
- Part 2: Application and registration procedures
An IIN is six digits in length. The leading digit is the major industry identifier (MII), followed by 5 digits, which together make up the IIN. This IIN is paired with an individual account identification number, and a single digit checksum.
Major industry identifier
The first (leading) digit of the IIN identifies the major industry of the card issuer.
|MII digit value||Issuer category|
|0||ISO/TC 68 and other industry assignments|
|2||Airlines, financial and other future industry assignments|
|3||Travel and entertainment|
|4||Banking and financial|
|5||Banking and financial|
|6||Merchandising and banking/financial|
|7||Petroleum and other future industry assignments|
|8||Healthcare, telecommunications and other future industry assignments|
|9||For assignment by national standards bodies|
MII 9 has been assigned to national standards bodies for national use. The first digit is a 9 followed by a three-digits numeric country code numeric-3 country code from ISO 3166-1. National Numbering Systems are managed by ISO-member national standards bodies. The US National Numbering system is managed by the American National Standards Institute.
Issuer identifier number
The first six digits, including the major industry identifier, compose the issuer identifier number (IIN) which identifies the issuing organization. The IIN is sometimes referred to as a "bank identification number" (BIN). The IIN's use is much broader than identification of a bank. IINs are used by companies other than banks.
The official "ISO Register of Issuer Identification Numbers", is not available to the general public. It is only available to institutions which hold IINs, are eligible for an IIN, or act as a financial network or processor. Institutions in the third category must sign a license agreement before they are given access to the Register. Several MIIs are well known, especially those representing credit card issuers.
Donald E. Eastlake wrote a series of Internet Drafts—the final of which was "ISO 7812/7816 Numbers and the Domain Name System (DNS)" (issued February 2001, expired August 2001)—proposing the lookup of card issuers automatically based on the IIN using the domain name system. Although the domain name for doing this, reg.int, was registered by the Internet Assigned Numbers Authority (IANA) the proposal floundered due to the opposition of the ISO/IEC 7812 and ISO/IEC 7816 registration authorities, who were concerned that this proposal caused security concerns for the issuers by making the information publicly available.
Individual account identification
In conjunction with the IIN, card issuers assign an account number to a card holder. The account number is variable in length with a maximum of 12 digits.
- "ISO/IEC 7812-1:2006 Identification cards - Identification of issuers - Part 1: Numbering system". Iso.org. 2009-09-28. Retrieved 2014-06-28.
- "ISO/IEC 7812-2:2007 Identification cards - Identification of issuers - Part 2: Application and registration procedures". Iso.org. 2009-09-28. Retrieved 2014-06-28.
- "draft-eastlake-card-map-08.txt". Retrieved 2014-06-28.