This TypeScript/JavaScript library validates IBAN and German bank account numbers. It can be used 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 the side project BankData-Germany.

• Installation
• Usage
• Data Source
• Package Version

Add it to your project with your package manager like npm or yarn. You should explicitly install the latest version since the bank data may change multiple times a year.

$ npm install --save ibantools-germany@latest
# or
$ yarn add ibantools-germany@latest

If you just want the functions in your browser, you can include the following pre-build file.

<script src="https://cdn.jsdelivr.net/npm/ibantools-germany/dist/build/browser.js"></script>

The npm package contains the code for ESM and CJS, so instead of import, as shown in the usage examples below, you can use require as well.

You can validate the bank account number and BLZ (Bankleitzahl = bank sort code), a BBAN or an IBAN. You can optionally restrict IBAN validation to only allow German IBAN.

import { isValidAccountNumberBLZ, isValidBBAN, isValidBIC } 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)

import { generateBBAN } from "ibantools-germany"

generateBBAN("9290701", "10220500"); // 102205000009290701
generateBBAN("foo", "bar"); // null

generateIBAN("9290701", "10220500"); // DE23102205000009290701
generateIBAN("foo", "bar"); // null

If you use the pre-build version, an object ibantoolsGermany is globally defined on window containing the functions.

ibantoolsGermany.generateBBAN("9290701", "10220500");
ibantoolsGermany.generateIBAN("9290701", "10220500");
ibantoolsGermany.isValidAccountNumberBLZ("9290701", "10220500");
ibantoolsGermany.isValidBBAN("102205000009290701");
ibantoolsGermany.isValidIBAN("DE23102205000009290701");

Sadly there is no algorithm to verify every German bank account number or BBAN. Each bank has its own method(s) which can change from time to time. Therefore Deutsche Bundesbank publishes updated data every quarter.

Updates can contain technical changes (modifications in check digit methods) and content changes (BLZ, bank names, etc). It is also possible that there are updates that do not contain any relevant changes for this library at all.

The version numbers are based on Semantic Versioning with modifications.

1.2205.3

The first number representes the Major version. If this number increases there are updates that may not be backward compatible and you have to adjust your code. That means the above version string is from major version 1.

The first two digits of the second number stand for the year of the included data and check digit methods. The third and fourth digit increase when there are either minor version changes that are backward compatible or when new data is included. That means the above version string is from year 2022 and has had a few minor updates, perhaps data updates for spring and summer.

The last number is for patches and bug fixes.

Since the data may change up to four times a year you should use a suitable version string in your package.json. Since there will be only breaking changes when the first number changes, you should be good with e.g. "1.x"