ISO Expands IIN from 6 to 8 Digits

The standard behind the issuer identification number used on many personal cards, for example credit cards, is changing, according to an ISO press release.

The IIN is the first six digits of the long number found on the front of debit or credit cards. The standardized global numbering scheme identifies the institution that issued the card.

The standard also defines the primary account number, which is used to identify an individual account holder. The PAN is of variable length, ranging from eight to 19 digits.

The IIN structure is defined within ISO/IEC 7812-1, "Identification cards — Identification of issuers — Part 1: Numbering system," developed by the ISO/IEC joint technical committee JTC 1, subcommittee SC 17, cards and personal identification.

According to the release the increasing number of card issuers is expected to cause a shortage in the available supply of IINs.

To solve this problem, ISO/IEC 7812-1 is being revised to expand the IIN from six to eight digits. The PAN will remain a variable length, ranging from 10 to 19 digits.

The draft of this revised standard has been approved by ISO members, with publication expected in early 2017.

Changes in the revised standard will mean that, as of the publication date:
- the Registration Authority will commence assigning eight-digit IINs to any institution applying for a single IIN or block of IINs;
- issuers with eight-digit IINs will be required to issue a minimum PAN length of 10 digits. The maximum will continue to be 19 digits in length;
- existing six-digit IINs will be converted into a block of a hundred eight-digit IINs. As the majority of issuers are unlikely to need all one hundred of these, they are encouraged to return any unused eight-digit IINs to the RA; and
 - any ISO/IEC standards referencing ISO/IEC 7812-1 should be reviewed for their potential effects.