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Germany IBAN Validator

Validates a German IBAN: the mod-97 checksum, the 22-character length and the structure, with the Bankleitzahl, or BLZ identified.

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In short A German IBAN is exactly 22 characters: DE, two check digits, then 8 digits, then 10 digits — so the 8 characters after the check digits are the Bankleitzahl, or BLZ — 37040044 in the example — and the remaining 10 are the account number, 0532013000. The eight digits after the check digits are the Bankleitzahl, the routing number German banks used before the IBAN and still print on statements. The ten digits after it are the account number, zero-padded on the left where the account is shorter. The checksum is ISO 7064 MOD-97-10: move the first four characters to the end, turn each letter into its position in the alphabet plus nine, and read the result as one long number, which must leave remainder 1 when divided by 97. That catches every single-character mistake and almost every swap of two neighbouring characters, which is what it was designed for and why an IBAN is worth checking before you pay rather than after. What it cannot do is tell you the account exists, is open, or belongs to the person you think — a random string of the right shape passes about once in 97 tries, and no amount of arithmetic reaches into a bank. This page runs entirely in your browser, so the number you type is not sent anywhere.

How to use the Germany IBAN Validator

  1. Paste the German IBAN — spaces and dashes are fine.
  2. Read the three checks: mod-97, length and structure.
  3. If it fails, the page says which check failed and what that usually means.

About the Germany IBAN Validator

Checks a German IBAN three ways — checksum, length and structure — and says which of the three failed when one does, because they mean different things.

What people use it for

  • Checking a German IBAN before sending money to it.
  • Finding the Bankleitzahl, or BLZ inside an IBAN you have been given.
  • Confirming a German number was typed or pasted correctly.

Details

Length22 characters, always
Structure8!n10!n after the check digits
In wordsDE, 2 check digits, then 8 digits, then 10 digits
Bankleitzahl, or BLZ8 characters — 37040044 in the example
ExampleDE89 3704 0044 0532 0130 00
Check digitsAlways between 02 and 98. 00, 01 and 99 cannot occur
PrivacyThe arithmetic runs in your browser. Nothing you type is sent anywhere

The maths behind it

This tool uses ISO 7064 MOD-97-10 — move the first four characters to the end, replace each letter with its position plus nine, and a valid IBAN leaves remainder 1 on division by 97. On top of that, German IBANs are exactly 22 characters and follow 8!n10!n. Every intermediate value is shown on screen, so the result can be checked by hand.

Three checks, reported separately on purpose. A length error means a character is missing or extra, a structure error means a letter sits where a digit belongs, and a checksum failure with both of those right means a genuine typo inside the number — most often two neighbouring characters swapped.

Where this tool stops

It checks arithmetic and shape. It cannot tell you the account exists or who it belongs to, it does not look the bank up, and it does not verify any national check digits Germany may use inside its own account number — those are separate rules, computed differently, and passing mod-97 says nothing about them.

Frequently asked questions

How many characters is a German IBAN?
Exactly 22, with no exceptions. After the two check digits the structure is 8!n10!n — 8 digits, then 10 digits. A number of any other length is not a German IBAN, whatever else about it looks right.
Where is the Bankleitzahl in a German IBAN?
Characters five to twelve — the eight digits immediately after DE and the two check digits. In DE89 3704 0044 0532 0130 00 the BLZ is 37040044 and the account is 0532013000.
Where is the bank code in a German IBAN?
The 8 characters after the check digits are the Bankleitzahl, or BLZ — 37040044 in the example — and the remaining 10 are the account number, 0532013000.
Does a valid checksum mean the account exists?
No, and this is the thing worth taking away. Mod-97 proves the number is internally consistent — that it was probably typed correctly. It says nothing about whether the account is open, or whose it is. A random string of the right length passes about once in every 97 attempts. Only the bank can confirm the rest.
Is it safe to paste an IBAN here?
The checking happens in your browser and the number is never sent to a server — there is no request to make one. An IBAN is not a secret the way a card number is, since it is printed on every invoice you send, but it is still yours, and it does not leave your machine here.
Is the Germany IBAN Validator free, or is there a paid tier?
It is free, with no account, no trial and no daily cap. Every security tool on inputtesthub.com works the same way: open the page and use it.
Does anything I enter leave my computer?
No. The Germany IBAN Validator runs entirely in your browser using JavaScript. Because the work happens locally, the tool also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
What is the equation behind the Germany IBAN Validator?
It uses ISO 7064 MOD-97-10 — move the first four characters to the end, replace each letter with its position plus nine, and a valid IBAN leaves remainder 1 on division by 97. On top of that, German IBANs are exactly 22 characters and follow 8!n10!n. The full working is printed under the result, so you can follow every step rather than trusting a black box.
Who is the Germany IBAN Validator for?
The most common reasons people reach for it: checking a German IBAN before sending money to it. Finding the Bankleitzahl, or BLZ inside an IBAN you have been given. Confirming a German number was typed or pasted correctly. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
When is the Germany IBAN Validator not the right tool?
It checks arithmetic and shape. It cannot tell you the account exists or who it belongs to, it does not look the bank up, and it does not verify any national check digits Germany may use inside its own account number — those are separate rules, computed differently, and passing mod-97 says nothing about them. Knowing where a tool stops being trustworthy matters more than the cases where it works.
Which values should I know?
Length is 22 characters, always. Structure is 8!n10!n after the check digits. In words is DE, 2 check digits, then 8 digits, then 10 digits. These are printed on the page itself, so you do not have to take them on trust.
Does the Germany IBAN Validator work on a phone?
Yes. The page is responsive and the tool works in Chrome, Safari, Firefox, Edge and Samsung Internet on both Android and iOS. There is no app to install and nothing to sign into.

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