The Composition of the Primary Account Number

The Primary Account Number (PAN) is the number on the front of most credit cards, debit cards and identification cards.

The PAN can also be used on some health-care cards and stored-value cards. It is usual practice for the PAN to be prominently embossed across the front of the card itself. The embossed PAN is a historical feature and reflective of its original function of being able to transfer a print of the PAN onto receipts when cards were manually processed with a credit card flatbed imprinter.

The PAN has common composition features that are in place across all types of cards, however, the PAN length does vary between issuers and card types. Most cards have a PAN of 16-19 digits long but the full range for all cards is 10-19 digits in length. The PAN is comprised of distinct parts that provides specific information.

The first 6 digits of the PAN - and more recently the first 8 digits - is known as the Issuer Identification Number (IIN). The issuer can be a corporation in the banking industry or an airline, travel and entertainment, merchandising, petroleum healthcare entities or other institutions or bodies not related to these major groups. The most prominent and greatest user of IINs are the banking industry who originally referred to the IIN as a Bank Identification Numbers (BIN), hence the overlapping terminology.

The very first digit of the PAN and consequently the very first digit of the the IIN is the Major Industry Identifier (MII). The MII are assigned to large but specific industry sectors.

The current assignment of MIIs to major industries are as follows:

Major Industry Identifier (MII) Issuer Category
0 International Standards Technical Committeess and other industry assignments
1 Airlines
2 Airlines, Financial and Others
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

The next 5 digits of the PAN after the MII make up the remainder of the IIN/BIN. The customer identification number is the next portion of the PAN. This number can identify individual accounts held by banking or merchandising customers for example. The customer identification number can be 4 to 13 digits long depending upon the system used by the affiliate member.

The final number of the PAN is often a check sum digit primarily used to help protect against accidental errors. It is calculated based on the digit composition of the IIN and customer identification number. Most credit and debit cards use the Luhn algorithm to calculate the check sum digit that is the final digit of the PAN.

The number of card issuers has been steadily growing, which is anticipated to create a shortage of IINs in the near future. As a result the International Organisation for Standardization and the International Electrotechnical Commission (ISO/IEC) has undertaken a revision of the standard for identification cards, the ISO/IEC 7812-1 and concluded that the IIN/BINs should be expanded from 6 digits to 8 digits. This would expand the possible number of available IIN/BINs from 1,000,000 to 100,000,000. The total length of the PAN will continue to be of varying length of 10 to 19 digits long.

The credit card industry typically divides up cards by the business of the issuer. There are the well known bank cards such as; VISA, UnionPay, Master Card and Discover, there are Petroleum Cards (SUN Oil, Exxon, etc.), and Travel and Entertainment cards (American Express, Diners' Club, Carte Blanche, etc). Cards that are not issued to these major industries are grouped into together as "Private Label" cards, which include department store cards, telephone cards, and similar. Most private label cards are only accepted by the issuer.