Part of the topic: 💶 Taxes & salary
German tax ID (Steuer-ID) checker
Enter an 11-digit German Steuer-ID to check it against the official structure and check-digit rules. The number never leaves your browser.
Store tax IDs, IBANs and passwords encrypted in a password manager.
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🔒 Runs entirely in your browser – nothing you enter is uploaded or stored.
How to use it
- Type the 11 digits (spaces are ignored).
- The checker tests length, the digit-repetition rule and the check digit.
- If it fails, the reason is shown – a typo is the most common cause.
Last checked: October 2026 · Based on: § 139b Fiscal Code; ISO 7064 Mod 11,10. Found a mistake? Use the form below – we fix confirmed errors and update the date.
Frequently asked questions
What is the Steuer-ID?
The German tax identification number (Steueridentifikationsnummer, IdNr) is an 11-digit number assigned to everyone registered in Germany by the Federal Central Tax Office (BZSt). It stays the same for life.
Where do I find my Steuer-ID?
On your income tax assessment, your payslip/annual payroll certificate, or the letter you received from the BZSt.
Which rules are checked?
No leading zero; in the first 10 digits exactly one digit occurs twice or three times (a triple may not be fully consecutive); the 11th digit is a check digit calculated from the first 10 (procedure published by ELSTER).