Germany Steuer-ID Validator
Check an 11-digit German Steuer-ID (tax identification number) with the official ISO 7064 MOD 11,10 check digit. 100% local. Built for Germany.
Batch check — paste many, one per line
Validate a German Steuer-ID
Enter an 11-digit German tax ID to check its format, required repetition pattern, and ISO 7064 MOD 11,10 check digit. Registration status is not verifiable offline.
FAQ
What is the Steuer-ID?
Germany’s 11-digit Steuerliche Identifikationsnummer (tax ID) for individuals. The 11th digit is a check digit.
Steuer-ID vs Steuernummer?
Steuer-ID is your personal lifelong 11-digit ID (never changes). Steuernummer is a 10–13 digit number assigned by your local Finanzamt for business tax returns — different purpose, different format.
How is it validated?
The tool checks the 11-digit format, the required repetition pattern in the first 10 digits, and then recomputes the ISO 7064 MOD 11,10 check digit.
Does a passing result confirm registration?
No. It confirms the number’s offline structure and check digit only. Registration status cannot be verified offline.
Is my number uploaded?
No. Validation runs entirely in your browser.
The Steuerliche Identifikationsnummer — the Steuer-ID, also written IdNr — is Germany's permanent 11-digit tax identification number, assigned by the Bundeszentralamt für Steuern and kept for life across moves and job changes.
Its structure is strictly defined: the first digit is never 0, and within the first ten digits exactly one digit repeats two or three times while every other digit appears once; a digit appearing three times may not sit in three consecutive positions. The eleventh digit is a check digit computed with the ISO 7064 MOD 11,10 procedure. This tool checks the length, the repetition pattern and the check digit locally in your browser, and names the exact rule that failed.
Do not confuse three different German numbers: the Steuer-ID stays with a person for life; the Steuernummer is issued by your local tax office and changes when you move; the USt-IdNr is the EU VAT identification number for businesses. Scope and limits: a structurally valid Steuer-ID is well-formed, but only the Bundeszentralamt für Steuern can confirm that a number was issued or to whom — this page never queries any register and sends nothing. Last verified: August 2026.
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