Issuer Identification Number (IIN) identify a card issuing institution in an international interchange environment.
The International Organisation for Standardisation (ISO) has introduced a standardised numbering system for the identification of card issuers. It is described in the following standards:
- ISO/IEC 7812 - Identification of cards - Identification of Issuers: Part 1: Numbering System
- ISO/IEC 7812 - Identification of cards - Identification of Issuers: Part 2: Application and registration procedures
All IINs assigned are six digit numbers and each card issuer is entitled to one IIN (outside of its membership of any card schemes, for example an IIN assigned from Visa). Therefore only one IIN will be assigned to each card issuer. This IIN must be used only to identify the card issuer. Additional IINs will not be issued to identify products, services or geographical location.