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 organisation 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, 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.
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
Major Industry Identifier (MII)
|M:||Major Industry Identifier|
|M + I:||Issuer Identification Number|
|A:||Account number, C: Check digit|
Format of a 16-digit credit card number
The first digit of a credit card number is the Major Industry Identifier (MII) (see ISO/IEC 7812), which represents the category of entity which issued the card. MII digits represent the following issuer categories:
- 0 – ISO/TC 68 and other future industry assignments
- 1 – Airlines
- 2 – Airlines and other future industry assignments
- 3 – Travel and entertainment and banking/financial
- 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 – National assignment
For example, American Express, Diner's Club, Carte Blanche, and JCB are in the travel and entertainment category; VISA, MasterCard, and Discover are in the banking and financial category (Discover being in the Merchandising and banking/financial category); and Sun Oil and Exxon are in the petroleum category.
Issuer identification number (IIN)
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 National Standards Institute (ANSI) and is updated monthly. ANSI is responsible for allocating IIN ranges to the issuing networks. The IIN database was previously managed by the American Bankers Association and continues to produce the official record of IIN assignment.
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.
|Issuing network||IIN ranges||Active||Length||Validation|
|American Express||34, 37||Yes||15||Luhn algorithm|
|Bankcard||5610, 560221-560225||No||16||Luhn algorithm|
|China UnionPay||62 or 88||Yes||16-19||no validation|
|Diners Club Carte Blanche||300-305||Yes||14||Luhn algorithm|
|Diners Club enRoute||2014, 2149||No||15||no validation|
|Diners Club International||300-305, 309, 36, 38-39||Yes||14||Luhn algorithm|
|Diners Club United States & Canada||54, 55||Yes||16||Luhn algorithm|
|Discover Card||6011, 622126-622925, 644-649, 65||Yes||16||Luhn algorithm|
|InstaPayment||637-639||Yes||16||Luhn algorithm|
|Laser||6304, 6706, 6771, 6709||No||16-19||Luhn algorithm|
|Maestro||5018, 5020, 5038, 5612, 5893, 6304, 6759, 6761, 6762, 6763, 0604, 6390||Yes||12-19||Luhn algorithm|
|Solo||6334, 6767||No||16, 18, 19||Luhn algorithm|
|Switch||4903, 4905, 4911, 4936, 564182, 633110, 6333, 6759||No||16, 18, 19||Luhn algorithm|
|Visa||4||Yes||13, 16||Luhn algorithm|
|Visa Electron||4026, 417500, 4405, 4508, 4844, 4913, 4917||Yes||16||Luhn algorithm|
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.
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 an so card number of more than 16 digits are now being seen.
Switch was re-branded as Maestro in mid-2007. 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:
|CIBC Convenience Card||4506||15 digits|
|Royal Bank of Canada Client Card||4519||16 digits|
|TD Canada Trust Access Card||589297 (regular debit)||19 digits|
|Scotiabank Scotia Card||4536||16 digits|
|BMO ABM Card||500X||16 digits|
|HSBC Canada Card||56XX||16 digits|
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.
- Bank account
- Card security code
- International Bank Account Number
- List of Issuer Identification Numbers
- Routing transit number
- ISO 9362 - Swift Code or BIC Code
- "What your credit card numbers mean". Retrieved 2010-12-07.
- ISO/IEC 7812-1:2006 Identification cards — Identification of issuers — Part 1: Numbering system
- ANSI Other Services - Issuer Identification Number (IIN)
- "Card Security Features" (PDF). American Express. January 2001. Archived from the original on 5 March 2006. Retrieved 2006-04-05.[dead link][dead link]
- "American Express Fraud Prevention Handbook" (PDF). p. 13. Retrieved 2006-04-05.
- "Bankcard Association of Australia". Archived from the original on 6 April 2006. Retrieved 2006-04-05.
- "China UnionPay Cards". Archived from the original on 14 November 2010. Retrieved 2010-11-26.
- "MasterCard Diners Club Alliance". Retrieved 2006-04-05.
- "Diner Club International accepted hand-in-hand with Discover and partners". Retrieved 2014-01-14.
- "Diners Club - Fraud Management". Retrieved 2007-01-26.
- "Discover Network - IIN Range Update, 8.2" (PDF). September 2008. Retrieved 2008-10-23.
- "Discover Network IIN Range Update, 9.2" (PDF). September 2009.
- "Laser Card Services Ltd.". 28 February 2009.
- "Discover Network - IIN Range Update, 9.1" (PDF). October 2008. Retrieved 2009-01-28.
- "Switch to Maestro". Archived from the original on 8 August 2010. Retrieved 2010-08-20.