Bank card number

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. Some card issuers refer to the card number as the primary account number or PAN. They have a certain level of internal structure and share a common numbering scheme. Bank card numbers are allocated in accordance with ISO/IEC 7812. The bank card number merely identifies 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.

An ISO/IEC 7812 card number is most commonly 16 digits in length,^[1] and can be up to 19 digits. The structure is as follows:

• a six-digit Issuer Identification Number (IIN) (previously called the "Bank Identification Number" (BIN)) the first digit of which is the Major Industry Identifier (MII),
• a variable length (up to 12 digits) individual account identifier,
• a single check digit calculated using the Luhn algorithm.^[2]

The bank card number differs from the Bank Identifier Code (BIC/ISO 9362, a normalized code - also known as Business Identifier Code, Bank International Code and SWIFT code). It also differs from Universal Payment Identification Code, another identifier for a bank account in the United States

Issuer identification number (IIN)

Partial IIN on a credit card (both printed and embossed)

The first six digits of a card number (including the initial MII digit) are known as the issuer identification number (IIN). These identify the institution that issued the card to the card holder. The rest of the number is allocated by the issuer. Cards are issued by the issuer through an issuing network. The card number's length is its number of digits. Many card issuers print the first four digits of the IIN on their card, just beneath where the number is embossed, as an added security measure.

In the United States, IINs are also used in NCPDP pharmacy claims to identify processors, and are printed on all pharmacy insurance cards. IINs are the primary routing mechanism for real-time claims. Each processor has one or more IINs, which it divides into plans by using Group Number and Processor Control Number fields.

The IIN database and membership is currently managed by the American Bankers Association and is updated monthly. ABA is responsible for allocating IIN ranges to the issuing networks.

Online merchants may use IIN lookups to help validate transactions. For example, if a card's IIN indicates a bank in one country, while the customer's billing address is in another, the transaction may call for extra scrutiny.

On November 8, 2004, MasterCard and Diners Club formed an alliance. Diners Club cards issued in Canada and the United States start with 54 or 55 and are treated as MasterCards worldwide. International cards use the 36 prefix and are treated as MasterCards in Canada and the United States, but are treated as Diners Club cards elsewhere. Diners Club International's web site makes no reference to old 38 prefix numbers, and they can be presumed reissued under the 55 or 36 IIN prefix. Effective October 16, 2009, Diners Club cards beginning with 30, 36, 38 or 39 have been processed by Discover Card.^[13]

On November 3rd 2014, Mastercard announced that they were introducing a new series of BIN ranges that begin with a “2” (222100–272099). The “2” series BINs will be processed the same as the “51–55” series BINs are today. They will become active 14th October 2016.

Effective October 1, 2006, Discover began using the entire 65 prefix, not just 650. Also, similar to the MasterCard/Diners agreement, China Union Pay cards are now treated as Discover cards and accepted on the Discover network.

Whilst the vast majority of Visa's account ranges describe 16 digit card numbers there are still a few (40 as of 11 Dec. 2013) account ranges dedicated to 13 digit PANs and several (439 as of 11 Dec. 2013) account ranges where the issuer can mix 13 and 16 digit card numbers. Visa's VPay brand can specify PAN lengths from 13 to 19 digits and so card numbers of more than 16 digits are now being seen.

Switch was re-branded as Maestro in mid-2007.^[14] In 2011, UK Domestic Maestro (formerly Switch) was aligned with the standard international Maestro proposition with the retention of a few residual country specific rules.

Canadian Bank Card Numbering

Canadian banks issue bank cards to access account also follow a pattern for their systems:

Security measures

To reduce the risk of credit card fraud, various techniques are used to prevent the dissemination of bank card numbers. These include:

• Format-preserving encryption – in which the account number is replaced with a strongly encrypted version which retains the format of the card data including non sensitive parts of the field such as first 6 and last 4 digits. This permits data field protection without changing payment IT systems and applications. A common use is for protecting card data from the point of capture in a secure reader to the payment processing host end-to-end to mitigate risk of data compromise in systems such as the Point of Sale (POS). AES-FF1 Format-Preserving Encryption is defined in NIST Specification SP800-38G.
• PAN truncation – in which only some of the digits on a card are printed on receipts. The PCI-DSS standards dictate that only the first 6 and last 4 digits of the PAN may be printed on the receipt. Generally only the last 4 digits are provided elsewhere to allow an individual to identify the card used.
• Tokenization – in which an artificial account number (token) is printed, stored or transmitted in place of the true account number.

See also

• Bank account
• Card security code
• International Bank Account Number
• Routing transit number
• ISO 9362 - Swift Code or BIC Code

References

External links

• H.P. Luhn and Automatic Indexing
• What your credit card numbers mean