# IBAN Key: `finance.banking.iban` International Bank Account Number (ISO 13616). Up to 34 alphanumeric characters: 2-letter country code (ISO 3166-1 alpha-2) + 2 check digits + up to 30 alphanumeric BBAN (Basic Bank Account Number) characters. Used for international money transfers. The mod-97 check digit algorithm provides strong detection signal. Page: Samples: `GB29NWBK60161331926819`, `DE89370400440532013000`, `FR7630006000011234567890189`, `NL91ABNA0417164300`, `ES9121000418450200051332`, `IT60X0542811101000000123456` ## Background ### Origin The International Bank Account Number (IBAN) is an internationally agreed system for identifying bank accounts across national borders, meant to ease the processing of cross-border transactions with a reduced risk of transcription errors.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Before IBAN, differing national standards for bank account identification were confusing for some users.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Under the national schemes that came before IBAN, necessary routing information was often missing from payments.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Routing errors delayed payments and added costs for the sending and receiving banks, and often for intermediate banks too.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) In 1997 the International Organization for Standardization (ISO) published ISO 13616:1997.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The European Committee for Banking Standards (ECBS) believed the flexibility of ISO 13616:1997 would make it unworkable.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The ECBS produced a slimmed-down version of the standard that permitted only upper-case letters and required the IBAN for each country to have a fixed length.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) ISO 13616:1997 was withdrawn and replaced by ISO 13616:2003.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) ISO 13616 was revised again in 2007, when it was split into two parts.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The current version is ISO 13616:2020, which names the Society for Worldwide Interbank Financial Telecommunication (SWIFT) as the formal registrar.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The IBAN check digits are calculated using MOD-97-10 as set out in ISO/IEC 7064:2003.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) ### Use An IBAN consists of up to 34 alphanumeric characters: a two-letter ISO 3166-1 alpha-2 country code, two check digits, and a Basic Bank Account Number (BBAN) of up to 30 country-specific alphanumeric characters.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The BBAN format is decided by the national central bank or designated payment authority of each country.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The BBAN must be of a fixed length for its country.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Permitted IBAN characters are the digits 0 to 9 and the Latin letters A to Z, even in countries such as Greece whose national language does not use those letters.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) IBANs are traditionally written in groups of four characters separated by spaces, with the last group of variable length.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) When an IBAN is transmitted electronically, the spaces are omitted.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Expect both forms in the same column, and strip spaces and upper-case each value before you check it. (Meridian's view) Validating an IBAN starts by checking that its total length is correct for its country.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Computing the mod-97 remainder of an IBAN in a single step needs integers of more than 60 digits.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Where software cannot handle integers that large, the modulo operation can be performed piece-wise.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Many countries also have their own national check digits inside the BBAN, with algorithms each country determines.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) The python-stdnum library's documentation says national checksums within the number are checked for only a few countries.[[2]](https://arthurdejong.org/python-stdnum/doc/1.20/stdnum.iban) Check the length for the country as well as the mod-97 remainder, and treat a pass as a sign that the value is well formed, not proof that the account exists. (Meridian's view) Banks in the United States do not use IBAN for U.S. accounts and use ABA routing transit numbers instead.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Canadian financial institutions have not adopted IBAN.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) Australia and New Zealand do not use IBAN.[[1]](https://en.wikipedia.org/wiki/International_Bank_Account_Number) A payee table that spans countries may hold IBANs on some rows and domestic account numbers on others, so a column that fails the IBAN check on a few rows may be mixed rather than dirty. (Meridian's view) ### Where you'll meet it Regulation (EU) No 260/2012 requires the payment account identifier for credit transfers and direct debits in euro to be the IBAN.[[3]](https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32012R0260) HMRC's page on paying a Self Assessment bill by bank transfer gives IBANs for payers whose account is overseas, such as GB62 BARC 2011 4770 2976 90.[[4]](https://www.gov.uk/pay-self-assessment-tax-bill/bank-details) ## Sources 1. [International Bank Account Number - Wikipedia](https://en.wikipedia.org/wiki/International_Bank_Account_Number) — secondary source 2. [stdnum.iban — python-stdnum 1.20 documentation](https://arthurdejong.org/python-stdnum/doc/1.20/stdnum.iban) — documentation 3. [Regulation (EU) No 260/2012 of the European Parliament and of the Council of 14 March 2012 establishing technical and business requirements for credit transfers and direct debits in euro and amending Regulation (EC) No 924/2009](https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32012R0260) — organisation 4. [Pay your Self Assessment tax bill: Make an online or telephone bank transfer - GOV.UK](https://www.gov.uk/pay-self-assessment-tax-bill/bank-details) — organisation