Payment card numbers are found on payment cards, such as credit cards and debit cards, as well as stored-value cards, gift cards and other similar cards. Card issuers refer to the leading six digits on the card as an "issuer identification number (IIN)", or "bank identification number (BIN)". On rare occasions they are referred to as bank card numbers. The remaining numbers on the card are referred to as the primary account number or PAN.
IINs and PANS have a certain level of internal structure and share a common numbering scheme. Bank card numbers are allocated in accordance with ISO/IEC 7812. This technical standard has two parts—Part 1 identifies the structure of the Issuer Identification Number. Part 2 identifies the application procedures and eligibility requirements for obtaining an IIN. The bank card number (or as it is commonly known, the IIN) identifies the issuer of the card, which is then electronically associated by the issuing organization with one of its customers and then to the customer's designated bank accounts. In the case of stored-value type cards, there is no necessary association with a particular customer.