International bank account number

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The International Bank Account Number ( English International Bank Account Number , abbreviated IBAN ) is an international standard for account numbers . It is described by the ISO standard ISO 13616-1 : 2007 Part 1.


Distribution of the IBAN (as of December 27, 2016)
  • IBAN structure is defined
  • IBAN structure is registered with SWIFT
  • Country adopts SEPA part
  • The euro is the national currency
  • The IBAN was developed to make the payment systems of the individual countries more uniform. The international standardization of the structure of check and account data (bank identification plus account identification) should open up integration and automation potential for data exchange between banks in different countries. In addition, internationally standardized information on bank details should also be advantageous for companies and private individuals , since there are no possible sources of error.

    At the time, promoted by the USA - which themselves have not yet implemented the IBAN - the countries of the European Union are currently the driving force behind the use of the IBAN. Other countries outside of Europe are also continuously adopting this notation, particularly in the Mediterranean, the Middle East and Central and South America.

    In January 2007, the ISO appointed the Society for Worldwide Interbank Financial Telecommunication (SWIFT) as the registration authority for national IBAN formats.

    The conventions for the IBAN structure were made on the premise that it is not practicable or enforceable to define an internationally uniform method for identifying bank details. The notations for bank accounts in different countries vary considerably; For example, the separation of sort code used in Germany to identify the bank and bank account number to identify the account is not even widespread in Europe. Accordingly, the IBAN notation was designed to take into account the different local notations for bank details and to enable the different local bank details to be transformed into a uniform IBAN structure. ISO 13616-1: 2007 Part 1 defines the details described below on the composition or structure as well as on the calculation and verification of the check digits.

    Differentiation from other systems

    While the IBAN is basically defined as a globally unique name for an account, this function cannot currently be used for all accounts in the world. The background to this is the definition of IBAN structures that was only made for 77 countries and territories until May 2020.

    The European Committee for Banking Standards (ECBS), which existed until 2006, expected that the process of worldwide acceptance could take five to ten years. At least until then it would be necessary to continue to use the current representation of bank details ( BIC and account number) in accordance with ISO 9362 in countries without IBAN for the secure processing of international payment transactions. Even after that, the use of BIC and IBAN would remain longer, because the IBAN did not basically contain all the routing information required for the systems at that time, which is defined using BIC . Considerations as to how the systems should be adapted, at least in the European area, in order to subsequently be able to do without the BIC, have already been made.

    With the decision to make IBAN mandatory, it was decided in 2012 that the BIC will no longer be used for SEPA transfers from February 1, 2016 .


    The IBAN is currently mainly used for payment transactions within the European Union . This applies both to the data carrier exchange procedure and to payment transactions with forms (payment transaction forms). In contrast, the bank account number is still used and not the IBAN. Checks also still carry the account number and the old bank code. A card can still only be blocked with an account number and bank code.

    EU transfers

    Within the European Union , the use of the IBAN was one of the requirements for carrying out EU transfers , which were carried out by the banks at the same cost as transfers within a country ( Regulation (EC) No. 924/2009 , previously Regulation (EC) No. 2560/2001 ). The EU transfer was created as part of the introduction of the euro and was in force from 2003 to 2013. Its successor is the SEPA transfer. The EU transfer was only binding for amounts in euros (EUR) and for member currencies of those countries that had extended the directive to their retained national currency (de facto only the Swedish krona (SEK)).

    When the EU transfer was introduced, there was no electronic payment system that enabled Europe-wide payment with the IBAN alone - therefore, in addition to the IBAN, the BIC of the internationally valid SWIFT payment system had to be specified for the EU transfer. SWIFT does not define a data format for transfer information; the evaluation of account information for a transfer is the responsibility of the two banks involved.

    SEPA transfer

    Building on the EU transfer, it was decided to establish the European Payments Area (SEPA) as a uniform euro payments area, which will completely replace the national payment systems from February 1, 2014. The aim is to standardize the payment systems so that there is no difference between a national and a Europe-wide payment. A new, XML- based SEPA data format was developed for this purpose . Since January 2009 the banks have been obliged to offer SEPA transfers and since November 2009 to offer a SEPA direct debit. Since SEPA transfer data can also be transported via SWIFT, it is also common to query the SWIFT BIC in addition to the IBAN.

    To further replace the national payment systems, the Central Credit Committee (ZKA; today Die Deutsche Kreditwirtschaft ) has designed the new EBICS ( Electronic Banking Internet Communication Standard ) payment protocol for the transmission of payment transaction data , which has been used by everyone since January 1, 2008 as a result of changes to the EDI agreement to support German banks. With EBICS, transfer information can be given via IBAN and SWIFT-BIC or via account number and bank code.

    Domestic transfer with IBAN

    Since 2009, the Swiss banking institutions have been recommending the general conversion of the previous account information to IBAN. Although the German banking industry only makes SEPA transfers mandatory for cross-border transactions, it can also be used for domestic destinations. If the bank has not yet switched to a uniform clearing procedure (with EBICS), the transfer can be technically carried out in different ways - as a result, transfers with SEPA / IBAN can appear as international transfers in the account statement, which also goes beyond of 50,000 euros, there is uncertainty as to whether the fees will be billed identically, and the SEPA transfer (temporarily until 2012) also allowed settlement within three working days instead of one. Since the obligation to support old protocols ( FTAM ) was no longer required in Germany at the end of 2010 , a general standardization of the technical infrastructure was expected from 2011 to avoid such results.

    A Europe-wide harmonization of the payment systems was planned for 2012, since SEPA transfers can replace national transfers. The prerequisite for this is that the SEPA standardization is extended to all national forms of payment (such as check payments and credit card payments) in order to be able to switch off the previous national payment channels. The indication of the IBAN results in a valid account connection for national and Europe-wide payment transactions in all member countries. After a transition period until February 1, 2014, the old national bank accounts are to be switched off.

    IBAN requirement

    On February 1, 2016, the IBAN replaced the existing national account numbers for transfers in the EU.

    The European Parliament had called for an end to the national procedures with a deadline of December 31, 2012. The Deutsche Bundesbank supported this proposal, although there was strong opposition from the German banking institutions. The resolution proposal of the European Commission of December 16, 2010 named 2013 as the date for the IBAN requirement for bank transfers and 2014 for direct debit. The transition periods should be 12 or 24 months.

    In addition to technical concerns that the Bundesbank considered solvable by the end of 2011, the main point against the IBAN requirement was that the IBAN format was too demanding for customers. The option of omitting the BIC for IBAN transfers was not supported at a COGEPS (contact group on Euro payments strategy) meeting, as in some countries the IBAN does not contain sufficient routing information for clearing. Since the IBAN in countries like Germany and Austria contains the established national bank code, the IBAN information there is sufficient for cash clearing of domestic transfers, but only the STUZZA in Austria had defined a procedure for this in 2006.

    In Switzerland, since January 1, 2006, the banks switched to the IBAN format with 21 digits. During the transition period, the old account numbers (with up to 16 digits) were still accepted. The use of the beneficiary's IBAN has been mandatory since January 1, 2010 - banks are allowed to reject transfers without an IBAN, but many banks do not make use of this right. In the case of domestic transfers, the routing is carried out using the BC number that is coded in the IBAN. For online transfers, it is common practice to automatically fill in the field with the BC number when entering the IBAN.

    The EU Parliament, Council and Commission agreed on the IBAN requirement on December 20, 2011; this was officially confirmed on February 14, 2012. By February 1, 2014, the national payment systems had to be converted to IBAN for transfers and direct debits; however, there were renewed transition periods in Germany until August 1, 2014 and February 1, 2016, see European Payments Area . The use of the BIC for domestic transfers with the IBAN was also discontinued from February 1, 2014; it no longer applies to cross-border EU transfers since February 1, 2016. The resistance of the German banking industry was eliminated by a compromise, according to which the electronic direct debit procedure with the right of return according to the German model is included in the SEPA standard; a template for an extended payment services directive is to be submitted by November 1, 2012. The revised “Direct Debit Scheme Rulebook” of the SEPA direct debit scheme now includes two variants - the “SEPA Core Direct Debit” and the “SEPA B2B Direct Debit”. With the basic direct debit, and only there, there is the option of reversing the booking within 8 weeks (56 days) without giving a reason. In both variants, however, if there is evidence of a missing collection order, an application for a SEPA chargeback is possible within a period of 13 months after the debit date. In the same regulation EC 260/2012, which requires the use of the IBAN, the acceptance of the SEPA direct debit is required on February 1st, 2014.


    IBAN number on a (fictitious) British bank statement

    For electronic processes, grouping using separators according to ISO 13616-1: 2007 Part 1 is not permitted, as computers would otherwise operate with incorrect values ​​or must always remove the separators before the actual processing. However, electronic processes only mean communication between computers, not communication between computers and people.

    DE07123412341234123412 "machine- friendly " without grouping

    In paper- or document-based processes - for example, representation on bank statements, invoices, etc. - has prevailed, the signs of the IBAN for better legibility starting from the left in groups of four by white space to group. When creating documents, with digital documents or account printouts, i. d. Usually a space is used as a separator. This form is prescribed by DIN 5008 .

    DE07 1234 1234 1234 1234 12 DIN form, usual "paper form", grouped by spaces

    The visual grouping of four is also established for the human-machine interface , for example input into electronic forms or reproduction for further use. As explained under “Composition”, the account number can also consist of letters (e.g. the name of the account holder). Therefore, grouping four does not always improve legibility . The ISO standard therefore deliberately does not formulate any specifications or restrictions for implementation.

    When entering: With some software systems, additional spaces are automatically inserted by the user during the character input for the purpose of better legibility, which are then removed again before the actual processing. This implementation does not always increase the legibility e.g. B. the IBAN "CH12 0483 5JOS EFMU ELLE R" is not more legible than "CH12 04835 JOSEF MUELLER". Other systems cannot process a delimited IBAN on their own.

    When outputting: Most operating systems with a graphical user interface and mouse operation allow you to mark (select) a single word by double-clicking it so that it can be copied. If an IBAN is shown on a website in "paper form", a double click would only select a single group of digits due to the spaces. By marking and copying the entire IBAN, the separators would also be included in the copied. For example, using CSS , a character string can be grouped visually without additional separators. A double click on an IBAN formatted in this way marks it in its entirety.

    DE07 1234 1234 1234 1234 12 “people-friendly”, visually grouped characters are treated as a single word

    Deviation from the norm: some (German) banks sometimes group the IBAN on their statements etc. according to bank code and account number. This is ISO-compliant, but not permitted according to DIN 5008.

    DE07 12341234 1234123412 Deviation from the standard, supports the conversion


    The IBAN is made up as follows:

    • 2-digit country code according to ISO 3166-1 (consisting of capital letters)
    • 2-digit checksum with check digits according to ISO 7064 (consisting of digits)
    • Account identification with a maximum of 30 digits (consisting of letters A – Z, a – z or numbers)
    General structure of the IBAN
    1 2 3 4th 5 6th 7th 8th 9 10 11 12 13 14th 15th 16 17th 18th 19th 20th 21st 22nd 23 24 25th 26th 27 28 29 30th 31 32 33 34
    country Check digits Account identification

    The IBAN can have a maximum of 34 digits, but is shorter in most countries.


    German IBAN (22 digits)
    1 2 3 4th 5 6th 7th 8th 9 10 11 12 13 14th 15th 16 17th 18th 19th 20th 21st 22nd
    DE Check Bank code Bank account number
    Austrian IBAN (20 digits)
    1 2 3 4th 5 6th 7th 8th 9 10 11 12 13 14th 15th 16 17th 18th 19th 20th
    AT Check Bank code Bank account number
    Swiss IBAN (21 characters)
    1 2 3 4th 5 6th 7th 8th 9 10 11 12 13 14th 15th 16 17th 18th 19th 20th 21st
    CH Check Bank clearing no. Bank account number

    Shorter account numbers are padded to the required number of digits after the bank code with leading zeros. As a - simplified, manual - filling-out aid in the German-speaking countries, this results in: After two digits, country code and two digits of new checksum, the bank code (D, A) / BC number (CH) is entered from the 5th digit, followed by the account number ( including the sub-account number) right-justified (starting from the right "backwards") from the last position - any remaining open positions in between are padded with zeros. If the account number has 7 or fewer digits, two of the zeros to be added are sometimes entered at the end of the IBAN before the account number is added right-justified from there and further filling with zero (s) takes place.

    IBAN structure in different countries

    Country code (ISO 3166 ALPHA-2) country length IBAN format Officially awarded (ISO 13616)
    EG Egypt 27 EG pp kkkk kkkk kkkk kkkk kkkk kkk Yes
    AL Albania 28 AL pp bbb s sss K kkkk kkkk kkkk kkkk Yes
    Double room Algeria 24 DZ pp bbb s ssss kkkk kkkk kk KK No
    AD Andorra 24 AD pp bbbb ssss kkkk kkkk kkkk Yes
    AO Angola 25th AO pp bbbb ssss kkkk kkkk kkk K K No
    AZ Azerbaijan 28 AZ pp bbbb kkkk kkkk kkkk kkkk kkkk Yes
    bra Bahrain 22nd BH pp bbbb kkkk kkkk kkkk kk Yes
    BE Belgium 16 BE pp bbb k kkkk kk KK Yes
    BJ Benin 28 BJ pp bbbb b sss ss kk kkkk kkkk kk KK No
    BA Bosnia and Herzegovina 20th BA pp bbb s ss kk kkkk kk KK Yes
    BR Brazil 29 BR pp bbbb bbbb ssss s kkk kkkk kkkk k Yes
    VG British Virgin Islands 24 VG pp bbbb kkkk kkkk kkkk kkkk Yes
    BG Bulgaria 22nd BG pp bbbb ssss dd kk kkkk kk Yes
    BF Burkina Faso 27 BF pp bbbb b sss ss kk kkkk kkkk k KK No
    BI Burundi 16 BI pp kkkk kkkk kkkk No
    CR Costa Rica 22nd CR pp 0kkk kkkk kkkk kkkk kk Yes
    CI Côte d'Ivoire (Ivory Coast) 28 CI pp bbbb b sss ss kk kkkk kkkk kk KK No
    DK Denmark 18th DK pp bbbb kkkk kkkk k K Yes
    DE Germany 22nd DE pp bbbb bbbb kkkk kkkk kk Yes
    DO Dominican Republic 28 DO pp bbbb kkkk kkkk kkkk kkkk kkkk Yes
    SV El Salvador 28 SV pp bbbb kkkk kkkk kkkk kkkk kkkk Yes
    EE Estonia 20th EE pp bb kk kkkk kkkk kkk K Yes
    FO Faroe Islands 18th FO pp bbbb kkkk kkkk k K Yes
    FI Finland 18th FI pp bbbb bb kk kkkk k K Yes
    FR France 27 FR pp bbbb b sss ss kk kkkk kkkk k KK Yes
    GA Gabon 27 GA pp bbbb b sss ss kk kkkk kkkk k KK No
    GE Georgia 22nd GE pp bb kk kkkk kkkk kkkk kk Yes
    GI Gibraltar 23 GI pp bbbb kkkk kkkk kkkk kkk Yes
    GR Greece 27 GR pp bbb s sss k kkkk kkkk kkkk kkk Yes
    GL Greenland 18th GL pp bbbb kkkk kkkk k K Yes
    GT Guatemala 28 GT pp bbbb kkkk kkkk kkkk kkkk kkkk Yes
    IQ Iraq 23 IQ pp bbbb sss k kkkk kkkk kkk Yes
    IR Iran 26th IR pp kkkk kkkk kkkk kkkk kkkk kk No
    IE Ireland 22nd IE pp bbbb ssss ss kk kkkk kk Yes
    IS Iceland 26th IS pp bbbb ss kk kkkk XXXX XXXX XX Yes
    IL Israel 23 IL pp bbb s ss kk kkkk kkkk kkk Yes
    IT Italy 27 IT pp K bbb bb ss sss k kkkk kkkk kkk Yes
    JO Jordan 30th JO pp bbbb ssss kkkk kkkk kkkk kkkk kk Yes
    CM Cameroon 27 CM pp bbbb b sss ss kk kkkk kkkk k KK No
    CV Cape Verde 25th CV pp bbbb ssss kkkk kkkk kkk K K No
    concentration camp Kazakhstan 20th KZ pp bbb k kkkk kkkk kkkk Yes
    QA Qatar 29 QA pp bbbb kkkk kkkk kkkk kkkk kkkk k Yes
    CG Congo (Brazzaville) 27 CG pp bbbb b sss ss kk kkkk kkkk k KK No
    XK Kosovo 20th XK pp bbbb kkkk kkkk kkkk Yes
    MR Croatia 21st HR pp bbbb bbb k kkkk kkkk k Yes
    KW Kuwait 30th KW pp bbbb kkkk kkkk kkkk kkkk kkkk kk Yes
    LV Latvia 21st LV pp bbbb kkkk kkkk kkkk k Yes
    LB Lebanon 28 LB pp bbbb kkkk kkkk kkkk kkkk kkkk Yes
    LI Liechtenstein 21st LI pp bbbb b kkk kkkk kkkk k Yes
    LT Lithuania 20th LT pp bbbb b kkk kkkk kkkk Yes
    LU Luxembourg 20th LU pp bbb k kkkk kkkk kkkk Yes
    MG Madagascar 27 MG pp bbbb b sss ss kk kkkk kkkk k KK No
    ML Mali 28 ML pp bbbb b sss ss kk kkkk kkkk kk KK No
    MT Malta 31 MT pp bbbb ssss s kkk kkkk kkkk kkkk kkk Yes
    MR Mauritania 27 MR pp bbbb b sss ss kk kkkk kkkk k KK Yes
    MU Mauritius 30th MU pp bbbb bb ss kkkk kkkk kkkk kkk K KK Yes
    MD Moldova 24 MD pp bb kk kkkk kkkk kkkk kkkk Yes
    MC Monaco 27 MC pp bbbb b sss ss kk kkkk kkkk k KK Yes
    ME Montenegro 22nd ME pp bbb k kkkk kkkk kkkk KK Yes
    MZ Mozambique 25th MZ pp bbbb ssss kkkk kkkk kkk K K No
    NL Netherlands 18th NL pp bbbb kkkk kkkk kk Yes
    MK North Macedonia 19th MK pp bbb k kkkk kkkk k KK Yes
    NO Norway 15th NO pp bbbb kkkk kk K Yes
    AT Austria 20th AT pp bbbb b kkk kkkk kkkk Yes
    TL East Timor 23 TL pp bbb k kkkk kkkk kkkk k KK Yes
    PK Pakistan 24 PK pp bbbb rr kk kkkk kkkk kkkk Yes
    PS Palestinian Territories 29 PS pp bbbb rrrr rrrr r kkk kkkk kkkk k Yes
    PL Poland 28 PL pp bbb s sss K kkkk kkkk kkkk kkkk Yes
    PT Portugal 25th PT pp bbbb ssss kkkk kkkk kkk K K Yes
    RO Romania 24 RO pp bbbb kkkk kkkk kkkk kkkk Yes
    SM San Marino 27 SM pp K bbb bb ss sss k kkkk kkkk kkk Yes
    ST Sao Tome and Principe 25th ST pp bbbb ssss kkkk kkkk kkk K K Yes
    SA Saudi Arabia 24 SA pp bb kk kkkk kkkk kkkk kkkk Yes
    SE Sweden 24 SE pp bbb k kkkk kkkk kkkk kkk K Yes
    CH Switzerland 21st CH pp bbbb b kkk kkkk kkkk k Yes
    SN Senegal 28 SN pp bbbb b sss ss kk kkkk kkkk kk KK No
    RS Serbia 22nd RS pp bbb k kkkk kkkk kkkk KK Yes
    SC Seychelles 31 SC pp bbbb bbbb kkkk kkkk kkkk kkkk XXX Yes
    SK Slovakia 24 SK pp bbbb ssss ss kk kkkk kkkk Yes
    SI Slovenia 19th SI pp bb ss s kkk kkkk k KK Yes
    IT Spain 24 ES pp bbbb ssss KK kk kkkk kkkk Yes
    LC St. Lucia 32 LC pp ssss bbbb kkkk kkkk kkkk kkkk kkkk Yes
    CZ Czech Republic 24 CZ pp bbbb kkkk kkkk kkkk kkkk Yes
    TN Tunisia 24 TN pp bb ss s kkk kkkk kkkk kk KK Yes
    TR Turkey 26th TR pp bbbb b r kk kkkk kkkk kkkk kk Yes
    UA Ukraine 29 UA pp bbbb bb kk kkkk kkkk kkkk kkkk k Yes
    HU Hungary 28 HU pp bbb s sss K kkkk kkkk kkkk kkk K Yes
    VA Vatican city 22nd VA pp bbb k kkkk kkkk kkkk kkkk kk Yes
    AE United Arab Emirates 23 AE pp bbb k kkkk kkkk kkkk kkk Yes
    GB United Kingdom
    including Jersey , Guernsey , Isle of Man
    22nd GB pp bbbb ssss ss kk kkkk kk Yes
    BY Belarus 28 BY pp ssss bbbb kkkk kkkk kkkk kkkk Yes
    CY Cyprus 28 CY pp bbb s ssss kkkk kkkk kkkk kkkk Yes
    CF Central African Republic 27 CF pp bbbb b sss ss kk kkkk kkkk k KK No

    AD, BE, ... Country code
    pp two-digit checksum
    b   position of the bank code
    d   account type
    k   position of the account number
    K   control characters (capital letter or number)
    r   regional   code
    s position of the branch code (branch code / code guichet)
    X   other functions

    1. Incl. French Guiana , French Polynesia , French Southern and Antarctic Lands , Guadeloupe , Martinique , Réunion , Mayotte , New Caledonia , Saint-Barthélemy , Saint-Martin , Saint-Pierre and Miquelon , Wallis and Futuna

    The IBAN without the country code and without the two-digit checksum is also known as the BBAN (Basic Bank Account Number).

    The French overseas territories have their own country codes (GF, GP, MQ, RE, PF, TF, YT, NC, BL, MF, PM, WF), but these are only used in the BIC for transfers, while the IBAN with the "FR" for France begins. The crown possessions of the British crown were assigned their own country codes in 2006 (IM, GG, JE), but they continue to use the IBAN with “GB” of the United Kingdom, which is also used for clearing.

    Generation of the IBAN

    The ECBS warns that an IBAN may only be created by the banking institute. This is based on the fact that there are several variants for the formation of the IBAN from the conventional bank code and account number, for example for the formation of the checksum or the omission of branch numbers.

    In order to keep the changeover effort low, the Deutsche Bundesbank and the Deutsche Kreditwirtschaft (formerly ZKA) have agreed on the conclusion of a new payment transaction agreement ("Agreement on IBAN rules"), which with effect from January 1, 2013 the holders of a German bank code obliged to disclose the IBAN training rules. The formation rules are summarized and the variant published as an additional field in the bank sort code file from June 3, 2013. The formation of the German IBAN shown above with the standard-compliant checksum formation was given the number 0000 00 and the omission of a bank code was given the number 0001 00 (variant 1 in version 0). With the first publication, 47 additional exceptions were documented, a description of the special rules comprises 150 pages and especially for the big banks up to 20 pages.



    As part of IPI and ECBS, the check digit procedure was set to the ISO 7064 mod 97-10 standard and adopted by the national standardization bodies of the banks. The checksum is in the range “02” to “98”, but due to different calculation methods used by different financial institutions, “00”, “01” and “99” also occurred. The corrections are largely complete. However, it cannot be ruled out that IBANs with “wrong” check digits still exist.

    1. To validate the checksum , a number is first created:
      This is made up of BBAN (in Germany e.g. 18 digits) + country code coded + checksum. The two letters of the country code and other letters contained in the account number are replaced by their position in the Latin alphabet + 9 (A = 10, B = 11,…, Z = 35).
    2. The remainder is now calculated, which results from the whole number dividing by 97 ( modulo 97).
    3. The result must be 1, otherwise the IBAN is wrong.

    Example 1

    1 IBAN DE 68 2105 0170 0012 3456 78
    2 Changeover 2105 0170 0012 3456 78 DE 68
    3 Modulo 210501700012345678 1314 68 mod 97 = 1


    By reversing the validation method, it is possible to generate correctly validating IBANs with regard to the formation of the checksums. The European Commerce Banking Services (ECBS) expressly point out that only the banks themselves issue correct IBANs. If you use a self-calculated IBAN, in the worst case scenario you risk losing your transfer. ISO 13616 already specifies that only financial institutions are allowed to generate an IBAN. The background to this is that the previous account number is not always right-aligned in the IBAN, but occasionally shifted by two digits - the last two digits then correspond to a previous sub-account.

    One possible algorithm for calculating the check digits is:

    1. Set the two check digits to 00 (the IBAN then starts with DE00 for Germany, for example).
    2. Put the first four characters at the end of the IBAN.
    3. Replace all letters with numbers, where A = 10, B = 11, ..., Z = 35.
    4. Find the integer remainder that remains after dividing by 97.
    5. Subtract the remainder from 98, the result is the two check digits. If the result is one-digit, it is supplemented with a leading zero.


    1. IBAN: DE 00 2105 0170 0012 3456 780000
    2. Changeover: 2105 0170 0012 3456 78 DE 00
    3. Modulo: 000210501700012345678 1314 00 mod 97 = 30
    4. Subtraction: 98 - 30 = 68

    Online validation

    Countless validation options can be found on the Internet. Some are country-specific, others are limited to the respective bank. All non-special validators check according to the method described above, some including additional country-specific checks, for example a consistency check of bank and account information.

    The UN CEFACT TBG5 has published a free IBAN validation service in 32 languages ​​for all 57 countries that have implemented the IBAN standard.

    When checking the IBAN DE68 2105 0170 0012 3456 78 (see example above), this service returns that the IBAN appears to be correct. This is because the country code is recognized, the internal structure matches this country code and the checksum is consistent with the rest of the IBAN. A disadvantage of this service is that the IBAN DE23 2004 1133 0008 3033 07 is also incorrectly recognized as correct. In this case, a correct checksum was calculated from a correct bank code 20041133 and a non-existent account number 8303307, for which the IBAN rules as published by the Bundesbank were not applied. This happened occasionally in the early days of the changeover to the IBAN when the conversion algorithm was not complete. In the specific example, 8303307 was the securities account number that the customer used - in the old account number system - as the account number. Internally, however, the account number was managed with two trailing 0's as 830330700. This was only visible in the IBAN that was made available to the customer by the custodian bank.

    If other services are used that take into account other regulations such as the Bundesbank's rules and regulations when calculating the IBAN from bank code and account number as well as when checking IBAN (as one of many tools), correct results are delivered. The apparently correct IBAN DE68 2105 0170 0012 3456 78 (see above) fails because of an incorrect check digit in the old account number (see Bundesbank regulations for calculating check digits for account numbers).

    In the second example with the (alleged) account number 8303307 and bank code 20041133, the computer recognizes, based on the IBAN rules of the Bundesbank, that it has to add two trailing 0's, and then generates the correct IBAN DE65 2004 1133 0830 3307 00. Validated If you use this calculator to generate the IBAN DE23 2004 1133 0008 3033 07 (which has a correct checksum), it detects a check digit error in the old account number according to the Bundesbank's publication on the check digit calculation for account numbers.

    Because of such pitfalls, some providers of commercial online IBAN validations and calculations offer correctness guarantees.

    Security of the checksum procedure

    Requirements of the ISO process, human typing behavior

    In the ISO standard is u. a. stated that a single wrong character is always recognized and a single number rotated between two adjacent or almost adjacent characters is almost always recognized. For several simultaneous errors, the probability of detection is still very high. It is not required that deliberate forgeries be detected.

    This is essentially based on typical human typing behavior. For numerical or predominantly numerical entries, as they are also given with an IBAN, a study on patient numbers has shown that people make systematic errors. The following were identified: typos in a single digit (49%), omission of a digit (27%), rotated number (9%), shift (6%), mirroring (2%), double entry of a digit (2%), other ( 5%). The ISO requirement covers all of these human errors; omissions or duplications are recognized in German IBANs because of the fixed length of the IBAN.

    Explanation of how the procedure works

    It is obvious that the process meets these requirements,

    1. since the calculation method provides for the calculation of mod 97,
    2. the number divided by 97 ends in 00
    3. and the last four digits before the constant 00 at the end were generated from the country code.

    Typically, a typo is one or two digits, rarely more. So that the checksum is still correct, the number from which the remainder is calculated (modulo) must either be increased or decreased by a multiple of 97 or a number is added and a second number is subtracted, with the integer remainder for both numbers at mod 97 is the same.

    The example DE68 2105 0170 0012 3456 78 from the calculation example above is used below.

    Such a change is generally ruled out for a single digit, as there are no multiples of 97 that consist of a digit from 1 to 9 at the front and only 0's afterwards.

    A simple approach to simulating typing errors of digits that are close together (i.e., rotated numbers) is to randomly select two adjacent digits, add or subtract 97 at this point, and then write back the result with carry over if necessary. For example, DE68 2105 0170 0012 3456 78 could be DE68 2105 0170 97 12 3456 78 (00 becomes 97), DE68 2105 0170 0 98 2 3456 78 (01 becomes 98) or DE68 2105 0170 0 109 3456 78 (012 becomes 109) can be generated by modifying two or three places close together. The "mistypes" generated in this way are the only ways to get correct checksums for adjacent digits. In this way, no two or three digit rotators can be generated. There are no two-digit numbers where the digits change position after adding (or subtracting) 97. In addition, numbers> 03 result in addition and <97 in subtraction, so that a third digit is changed. The “mistypes” that are possible in this way and that lead to a correct checksum cannot be generated on keyboards by simply tapping next to them, either in the number blocks or in the row of numbers on the keyboard.

    Since a typing error is only ever recognized in one place, at least one additional digit must be modified. For the number from the example above 210501700012345678131400 e.g. For example, the tenth digit could be arbitrarily changed from 0 to 9 as a simulated typing error, which would calculate 210501700912345678131400 mod 97 = 22; instead of 30. - You now have an IBAN DExx 2105 0170 0 9 12 3456 78, whereby the checksum xx = 68 is no longer correct. To do this, a second matching typo must be found.

    Theoretically, it is sufficient to add 8, whereby 210501700912345678131408 is included in the calculation so that the checksum 68 (or the remainder = 30) is correct again. However, since the last two digits are always 00, there cannot be a second typing error; you cannot generate an IBAN from this number.

    You need a suitable additive to generate an IBAN with the original checksum. Specifically, this means that you have to find a number that, after adding, turns the changed 0 into a 9, changes a second digit and does nothing else. So you first look for a maximum 18-digit number that contains two digits 1 to 9 (there are 12393 = 153 * 89, with 153 the sum from 1 to 17) and otherwise only consists of 0s. In these 12393 numbers there is a subset of 83 numbers that are divisible by 97 without a remainder and can therefore be used as additives for simulating typing errors.

    Instead, you can also search for tuples of numbers that result in the same remainder when divided by 97. Then one of the numbers is added and the other subtracted, canceling out the “shifted” remainders. Since only one digit should be manipulated at a time, the numbers in the tuple consist of a digit from 1 to 9 and otherwise only 0's. There are 158 such tuples in total, the smallest tuple being (100, 3), mod 97 results in 3 for both.

    To put it a bit more catchy: If you have already made a mistake in this one place, then with the German IBAN 17 you have other numbers to choose from, which you can make a mistake again. You can make a mistake 9 times in each of the 17 positions, giving you 153 possibilities. For the specific example, the number to be added would be 970000000 from the 83 available values ​​and the appropriate mistake would be DE68 2105 0170 0 98 2 3456 78. - If you are looking for a tuple for addition and subtraction, the only value is (900000000, 50), after adding the 900000000 and subtracting 50, a new IBAN would be DE68 2105 0170 0 9 12 3456 2 8. - In this specific case, you have two subsequent typing errors to choose from, where you can change a second digit to the original check digit comes. If the number and position are randomly selected, the result is 1.3% if the 0 in the specific IBAN was first made into 9 and then another number was changed at random.

    If the mistake was DExx 21 6 5 0170 0012 3456 78, the only one of the 83 numbers would be 6000000000000700 (6 zeros have to be added again for the actual addition). However, this would lead to a carryover, a third digit would be modified and the IBAN would be DE68 21 6 5 0170 0012 34 63 78. The possible tuples are 6000000000000000 with 9000, 300000 and 10000000. The subtraction of 9000 also leads to a carry, the other two numbers lead to matching checksums. You can see that there are constellations for certain IBANs in which, after a first typing error, the original checksum could not be generated with a second, but only with the help of further typing errors (e.g. DE56 2105 0170 1000 0456 78 according to DExx 21 6 5 0170 1000 0456 78).

    It is not enough to just make a mistake in two suitable places. You also have to be "lucky" with the IBAN itself so that you can get by with two digits. Esp. applies:

    • Rotating numbers of two adjacent digits are excluded, since the only possible additive is 97 (with further 0's on the right or left).
    • In the case of two adjacent digits, a matching double mistake is only possible if the left digit is a 0 and the right digit is 0, 1 or 2 (addition of 97 to the two digits); or when the left digit is a 9 and the right digit is a 9, 8 or 7 (subtracting 97). This means that 6 out of 100 digit combinations come into question that allow an unrecognizable mistake at all, then you have to type in exactly the right wrong digits and in all cases the digits are arranged on the keyboard in such a way that you cannot simply reach off the mark in both digits, esp . not if you z. B. shifted by one place into the keyboard.
    • Ultimately, all rotated numbers are excluded, provided that the rotated number is defined as: You draw two digits from the 18-digit number block (bank code + account number) and swap them. This is because the 83 additives mentioned above cannot be used to simulate a job swap. You always add or subtract, i.e. In other words, the two digits concerned grow when added or shrink when subtracted, until there is a carryover and thus a change in a third digit. To swap digits, however, it would be necessary for the smaller digit to grow and the larger to shrink. The 158 tuples also cannot be used to simulate an exchange of digits, since the two digits other than 0 in the numbers of the tuples would then have to be the same. But there are no such tuples.

    A general statistical statement on the possibility of incorrect transfers due to typing errors cannot be made. You can only make a statement for a specific IBAN in which a certain digit has been modified, how likely a further random change is in at least one place in order to keep the original checksum. In the first example, the probability was 1: 153. In the second example, after the first typing error, 2 adjacent digits have to be typed correctly. This means that after you have made a mistake in the first digit with a probability of 1: 153, you must also make a mistake in the second digit with a probability of 1: 144, whereby you have to type in 4 pairs of digits "right wrong".

    Normal human (typing) typing behavior virtually rules out such typing errors.

    For German IBANs, the fact that the 8-digit bank routing number can only have approx. 3600 different values ​​and that the 10-digit account number still has its own check digit procedures are made even more difficult. And even then, the randomly (v) typed bank details must exist for a wrong transfer.


    Criticism is often expressed about the length of the IBAN, whereby in the case of Germany (22 characters) it essentially consists of the previously used sequence of digits bank code and account number, supplemented by the preceding letter sequence "DE" and the two-digit check number.

    In order to make it easier to read , the IBAN is often divided into blocks of four on paper documents (see #spelling ). In electronic media, however, this division can lead to problems, for example if an IBAN is to be copied by copy & paste into the corresponding field of a transfer form in online banking. If this case is not taken into account and intercepted in the software, incorrect entries can occur.

    Some creditors or debtors refuse to use a foreign IBAN. This is what is known as IBAN discrimination , which runs counter to a uniform European payment area.

    See also

    • ISO 9362 , Business Identifier Code (BIC)

    Web links

    Background information

    Register of national IBAN formats

    Individual evidence

    1. a b c d ISO 13616 IBAN Registry. This registry provides detailed information about all ISO 13616-compliant national IBAN formats. Release 87 - May 2020. SWIFT SCRL, accessed on May 31, 2020 (English).
    2. a b c d
    3. a b Legislative resolution of the European Parliament of February 14, 2012 on the proposal for a regulation of the European Parliament and of the Council laying down the technical requirements for credit transfers and direct debits in euros and amending Regulation (EC) No. 924/2009 . February 14, 2012. Retrieved on February 14, 2012: “[Article 5] (7) After February 1, 2014 for domestic payments and after February 1, 2016 for cross-border payments, payment service providers no longer require their users to enter the BIC of the payment service provider of a payer or the payment service provider of a payee. "
    4. SEPA transfer. (No longer available online.) In: Deutsche Bundesbank, archived from the original on December 3, 2013 ; Retrieved December 6, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot /
    5. a b "Information event on payment transactions and account management ( Memento of the original from September 8, 2011 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. , Deutsche Bundesbank , November / December 2010. @1@ 2Template: Webachiv / IABot /
    6. ^ "Deadline for switching to SEPA products: Dt resistance programmed" ( Memento from December 17, 2010 in the Internet Archive ), Dow Jones Germany, December 14, 2010.
    7. DPA overview  ( page no longer available , search in web archivesInfo: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. “Brussels (dpa) - According to EU plans from 2013 onwards, Europe's bank customers must use international account numbers for all transfers. The national numbers should then be replaced by account numbers (IBAN) and bank codes (BIC) that are valid throughout the EU - even for transfers in your own country. Despite German concerns, EU Internal Market Commissioner Michel Barnier presented a corresponding proposal on Thursday. The changeover for direct debits should be completed in 2014. [...] ".@1@ 2Template: Toter Link /  
    8. "IBAN, the terrible" comes from 2013. Kronen Zeitung, December 16, 2010.
    9. "Extreme account numbers should come in 2013 at the latest" , Der Spiegel, July 28, 2010.
    10. "Status of preparation and plans as per December 2006" ( Memento of the original from January 13, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , "By use of an interbank agreement the Austrian banks intend to allow SEPA payments without BIC (IBAN only) if both ordering and receiving banks are within Austria." @1@ 2Template: Webachiv / IABot /
    11. IBAN number: Not yet mandatory. , November 29, 2009.
    12. (PDF; 717 kB) “For domestic bank payments, the IBAN or account number must be entered. If you use the IBAN, the BC number will be entered automatically as it is contained in the IBAN. "
    14. Manual SEPA Direct Debit (PDF; 272 kB) PostFinance. Retrieved December 23, 2018.
    15. Regulation (EU) No. 260/2012 laying down the technical regulations and business requirements for credit transfers and direct debits in euros and amending Regulation (EC) No. 924/2009 , accessed on March 13, 2013
    16. ISO 13616-1: 2007 Financial services - International bank account number (IBAN) - Part 1: Structure of the IBAN. Retrieved on September 28, 2014 (English): "... does not specify internal procedures, file organization techniques, storage media, languages, etc. to be used in its implementation ..."
    17. ISO 13616-1: 2007 (en) Financial services - International bank account number (IBAN) - Part 1: Structure of the IBAN. In: ISO Online Browsing Platform. International Organization for Standardization, 2007, accessed April 20, 2020 .
    18. ISO / IEC 7064: 2003 - Information technology - Security techniques - Check character systems. International Organization for Standardization, accessed January 31, 2010 .
    19. a b c IBAN Warning
    20. Conozca el IBAN: see below número de cuenta . ( [accessed January 24, 2017]).
    21. IBAN. (No longer available online.) Archived from the original on January 24, 2017 ; Retrieved January 24, 2017 (Spanish). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot /
    22. IBAN_registry.txt (tab-separated CSV file) . SWIFT. Archived from the original on April 29, 2014. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved on April 29, 2014: “FR. Note that French Republic regional country codes used for companies identification (BIC) do not contradict the generic FR country code at IBAN level. Regional and administrative French Republic subdivision country codes: French Guyana (GF), Guadeloupe (GP), Martinique (MQ), Reunion (RE), French Polynesia (PF) *, French Southern Territories (TF) *, Mayotte (YT), New Caledonia (NC) *, Saint Barthelemy (BL), Saint Martin (French part) (MF), Saint Pierre et Miquelon (PM), and Wallis and Futuna Islands (WF) *. " @1@ 2Template: Webachiv / IABot /
    23. Payments Council - IBANs in Europe . European Payments Council. Retrieved April 29, 2014: “In March 2006, ISO amended the international country code standard, assigning the Crown Dependencies (Jersey, Guernsey and the Isle of Man) codes, which could be used instead of GB. The amendment implied that IBANs (which include an ISO country code prefix) issued for accounts in the Crown Dependencies should no longer use the Great Britain prefix (GB), but [..] Members of the payments industry have taken the decision to continue using the GB prefix for accounts based in the Crown Dependencies and routed via UK clearing. "
    24. Circular No. 73/2012 Agreement on IBAN Rules . German Bundesbank. Retrieved June 11, 2013.
    25. IBAN rules - bank sort code file . German Bundesbank. Retrieved December 23, 2018.
    26. SEPA changeover with cKonto . NetSlave GmbH. June 5, 2013. Accessed on June 11, 2013: “The special rules published by the Bundesbank are a 150-page document, similar to the check digit procedure that was also published. To date, 47 exceptions to the IBAN generation have been defined in these “IBAN rules”. In particular, the special rules of large credit institutions, such as B. Deutsche Bank AG or Commerzbank AG, each comprise up to 20 pages. "
    27. Check digit procedure. (PDF) (No longer available online.) STUZZA Austria, archived from the original on June 12, 2013 ; Retrieved July 14, 2011 .
    28. Calculate the IBAN checksum . Iban de. 2008. Retrieved October 2, 2012.
    29. IBAN validation service of UN / CEFACT TBG5
    30. ^ Deutsche Bundesbank, IBAN rules
    31. Deutsche Bundesbank, check digit calculation for account numbers
    32. ISO 7064 , accessed May 24, 2019
    33. Identification of Special Patterns of Numerical Typographic Errors Increases the Likelihood of Finding a Misplaced Patient File . In: J Am Med Inform Assoc. 2002 Nov-Dec; 9 (6 Suppl 1): s78-s79. PMC 419425 (free full text).