IBAN Validator and Generator for German Bank Accounts
npm install ibantools-germany!CI: Lint, test and build
This TypeScript/JavaScript library validates IBAN and German bank account
numbers. It can be used standalone or as an enhancement of IBAN validators, like
IBANTools.
If you need German bank data in your project, e.g., to auto-fill forms when a
user enters an IBAN, take a look at the side project BankData-Germany.
> _Version 1.2503.* includes data from 2025-09-08 to 2025-12-07, as well as from 2025-12-08 to 2026-03-07. Validation will be based on the data that is valid according to your system time (data changes at midnight CET on 2025-12-08)._
* Installation
* Usage
* Data Source
* Package Version
Add it to your project using a package manager like npm or yarn. You should
explicitly install the latest version, as the bank data may change multiple
times a year.
``sh`
$ npm install --save ibantools-germany@latestor
$ yarn add ibantools-germany@latest
If you only want the functions in your browser, you can include the following
pre-built file.
`html`
The npm package contains the code for both ESM and CJS. Therefore, in addition
to using import as shown in the usage examples below, you can also utilizerequire.
You can validate the bank account number and BLZ (Bankleitzahl = bank sort
code), a BBAN, or an IBAN. Additionally, you have the option to restrict IBAN
validation to only allow German IBANs.
`javascript
import { isValidAccountNumberBLZ, isValidBBAN, isValidIBAN } from "ibantools-germany"
isValidAccountNumberBLZ("9290701", "10220500"); // true
isValidBBAN("102205000009290701"); // true
isValidBBAN("20041010050500013M02606"); // false (valid but not a German BBAN)
isValidIBAN("DE23102205000009290701"); // true
isValidIBAN("FR1420041010050500013M02606"); // true
isValidIBAN("FR1420041010050500013M02606", false); // false (only allow German IBAN)
`
`javascript
import { generateBBAN, generateIBAN } from "ibantools-germany"
generateBBAN("9290701", "10220500"); // 102205000009290701
generateBBAN("foo", "bar"); // null
generateIBAN("9290701", "10220500"); // DE23102205000009290701
generateIBAN("foo", "bar"); // null
`
When using the pre-built version, the ibantoolsGermany object is globallywindow
defined on the , containing the functions.
`javascript`
ibantoolsGermany.generateBBAN("9290701", "10220500");
ibantoolsGermany.generateIBAN("9290701", "10220500");
ibantoolsGermany.isValidAccountNumberBLZ("9290701", "10220500");
ibantoolsGermany.isValidBBAN("102205000009290701");
ibantoolsGermany.isValidIBAN("DE23102205000009290701");
Unfortunately, there isn't a single algorithm to verify all German bank account
numbers or BBANs, as each bank employs its own method(s) which can change
periodically. To address this,
Deutsche Bundesbank
publishes updated data every quarter.
These updates can encompass both technical changes, such as modifications in
check digit methods, as well as content changes like alterations to BLZ, bank
names, and more. Some updates might not contain any relevant changes for this
library at all.
The version numbers are based on Semantic Versioning
with some modifications.
> 1.2205.3
The first number represents the Major version. If this number increases, there
may be updates that are not backward compatible, requiring adjustments to your
code. In the above version string, the major version is 1.
The first two digits of the second number indicate the year of the included data
and check digit methods. The third and fourth digits increase either with minor
version changes that maintain backward compatibility or when new data is
included. In the provided version string, the year is 2022, with a few minor
updates, possibly including data updates for spring and summer.
The last number is reserved for patches and bug fixes.
Considering that the data could change up to four times a year, it's advisable
to use an appropriate version string in your package.json. As breaking changes
occur only when the first number changes, specifying something like "1.x"`
should suffice.