Check an IBAN

Enter an IBAN to see at once whether check digits, length, structure are correct. This page checks an existing IBAN; it does not build a new one: some banks have rules of their own for that, so only the bank can tell reliably. Your input stays in your browser

Basis: Check digits modulo 97-10 (ISO 7064), structure of the German IBAN per Deutsche BundesbankCalculated in your browser – nothing is stored

With or without spaces, upper or lower case. Prefilled is the sample pattern of Deutsche Bundesbank, not a real account.

Try it

The 22 characters of a German IBAN

All 22 characters are there, the check digits match the rest.

Your input stays in your browser: the check runs on your device. The IBAN is not sent, not stored, never part of the link.

Result of the check

Valid

The German IBAN is formally valid: 22 characters, the structure fits, the check digits 58 are correct.

  • Country codeGermany (DE)
  • Length22 of 22 characters
  • StructureOnly digits follow after DE
  • Check digits58 – the check leaves a remainder of 1
German bank code (Bankleitzahl)
12345678
characters 5 to 12
Account number
0123456789
characters 13 to 22, with leading zeros

RZ-26 · headon.pro

The check itself: modulo 97 with this IBAN

This is how to redo the check with a pocket calculator.

  1. 1. Move the first four characters to the end

    123456780123456789 DE58

  2. 2. Replace letters with numbers: D = 13, E = 14

    123456780123456789131458

  3. 3. Divide by 97, keep the remainder – piece by piece

    123456780 mod 97 = 30
    301234567 mod 97 = 0
    08913145 mod 97 = 9
    98 mod 97 = 1

    The remainder of one piece goes in front of the next digits. That keeps every number short enough for a pocket calculator; the result is the same.

  4. Remainder 1 – the check digits 58 are correct.
  5. Cross-check: with "00" in place of the check digits the remainder is 40. 98 − 40 = 58 – these are the check digits that belong to this account identifier.

What you can do

  • Before the transfer, compare recipient plus IBAN with the invoice

    The check finds typing errors. Whether the account exists, who owns it, only the bank can establish.

  • Account number looks different from what you know?

    Some banks build the IBAN under a rule of their own – then the account number inside the IBAN can differ from the former account number.

  • Finding your own IBAN

    This page does not build an IBAN from a German bank code plus account number, because some banks have a special rule for it. Your IBAN is printed on your bank statement, on your bank card, in online banking.

How the check works
  1. Remove spaces as well as separators, write letters in upper case.
  2. Check the form: two letters for the country, two digits as check digits, at most 34 characters in total. For German IBANs in addition: exactly 22 characters, only digits after DE.
  3. Move the first four characters (country code, check digits) to the end.
  4. Replace letters with numbers: A = 10, B = 11 … Z = 35.
  5. Divide the resulting number by 97. If the remainder is 1, the check digits are correct.

For every IBAN the check digits plus the general form are verified; for German IBANs also length plus structure.

Method, general form: European banking standard EBS204, clauses 5 to 6 (modulo 97-10 under ISO 7064). Length, structure of the German IBAN: Deutsche Bundesbank, IBAN rules.

Formal check: a formally valid IBAN can belong to an account that does not exist (any more).

Checking an IBAN: what this page verifies

An IBAN is built so that typing errors can be spotted before money is transferred. For every IBAN the check recalculates the check digits, checking the general form too: two letters for the country, two check digits, at most 34 characters in total. For a German IBAN it also verifies the length of 22 characters plus the structure, showing bank code with account number.

For other countries this page verifies the check digits only: how long an IBAN has to be per country is available to us as an official statement for Germany alone (Deutsche Bundesbank). The result therefore always states what was verified.

The check is pure arithmetic that runs entirely in your browser. The IBAN is not sent to a server, not stored, never written into the link of the page. The check covers the form – whether the account exists, who owns it, only the bank can tell.

What the check shows

The IBAN as a band
Country, check digits, bank code, account number side by side with labels – green for what is correct, red for where the error sits
Result with the reason
Wrong check digits, wrong length, wrong structure are reported separately
A check you can redo
Modulo 97 step by step with the digits of your IBAN
Honest scope
German IBAN: length, structure, check digits. Other countries: check digits only

How a German IBAN is structured

In Germany the IBAN has 22 characters: first the country code DE, then two check digits, followed by the eight-digit bank code (Bankleitzahl), finally the ten-digit account number. Shorter account numbers are padded with leading zeros to ten digits. This is how Deutsche Bundesbank describes it.

Sample pattern of Deutsche Bundesbank: DE58 1234 5678 0123 4567 89 – bank code 12345678, account number 0123456789, check digits 58. On paper the IBAN is written in groups of four, electronically without spaces.

The 22 characters of a German IBAN

  1. 1Positions 1–2: country codeDE for Germany – two letters under ISO 3166.
  2. 2Positions 3–4: check digitsTwo digits, calculated from all other positions (modulo 97).
  3. 3Positions 5–12: bank codeEight digits that identify the payment service provider.
  4. 4Positions 13–22: account numberTen digits; shorter account numbers start with zeros.

Calculating IBAN check digits: modulo 97

The check digits follow the method modulo 97-10 (ISO 7064). To validate, the first four characters – country code with check digits – are moved to the end, letters are replaced by numbers (A = 10, B = 11 … Z = 35), then the resulting number is divided by 97. If the remainder is 1, the check digits are correct.

To calculate them, "00" is put in place of the check digits first, the same steps follow, then the remainder is subtracted from 98. Example from the European banking standard EBS204: for the Belgian account identifier 510007547061 the division leaves a remainder of 36; 98 − 36 = 62 – the IBAN is BE62 5100 0754 7061. A single-digit result gets a leading zero.

Why this page does not calculate an IBAN

Whoever looks for an IBAN calculator usually wants one of two things: to check an IBAN, or to build it from bank code plus account number. This page checks. As a rule the German IBAN results from the bank code, the account number padded to ten digits, plus the check digits. Not everywhere, though: some payment service providers have IBAN rules of their own – for certain ranges of account numbers, for example. Which rule applies to a bank code is listed in the extended bank code file of Deutsche Bundesbank, which is provided to registered legal entities only.

Because the result would be wrong for some banks without these rules, this page does not build an IBAN from bank code plus account number. Your IBAN is printed on your bank statement, on your bank card, in online banking; if in doubt, your bank will tell you. You can check any IBAN here.

Frequently asked questions about checking an IBAN

Length, check digits, bank code, privacy

How many characters does a German IBAN have?

22: the country code DE, two check digits, eight digits of bank code, ten digits of account number. IBANs of other countries differ in length, with at most 34 characters; this page does not verify their length.

How do I check an IBAN?

Enter the IBAN above. The page recalculates the check digits: first four characters to the end, letters into numbers, divide by 97 – the remainder must be 1. For a German IBAN it verifies length plus structure as well.

What does "formally valid" mean?

For a German IBAN: length, structure, check digits are correct. For IBANs of other countries the page only reports "check digits correct". A single wrong digit, likewise two neighbouring digits swapped, is caught by this check. The check does not tell whether the account exists or who owns it; only the bank establishes that.

How do I read bank code plus account number from an IBAN?

In a German IBAN, DE with the two check digits is followed by eight digits of bank code, then ten digits of account number. DE58 1234 5678 0123 4567 89 gives bank code 12345678, account number 0123456789. Leading zeros pad the account number to ten digits.

Is my IBAN stored or transmitted?

No. The check runs in your browser. The IBAN is not sent to a server, not stored, not written into the link of the page.

Can I calculate my IBAN from account number plus bank code here?

No, deliberately not. Some banks build the IBAN under a special rule; without it the result would be wrong. The IBAN is printed on your bank statement, on your bank card, in online banking.

Can I check a foreign IBAN too?

Yes, its check digits: they are calculated by the same method for every IBAN. Whether the IBAN has the length required for the country, with the right structure, is verified on this page for Germany only.