Last checked against the official sources: 29 August 2026
The German tax identification number (steuerliche Identifikationsnummer, IdNr) is an eleven-digit number issued to you once, for life. It does not change when your address, your job or your marital status changes. Without it your employer withholds tax at the highest bracket, and you cannot claim a refund or receive child benefit. You never apply for it — and nobody will ever read it out to you over the phone.
The essentials
- Responsible authority
- The Federal Central Tax Office (Bundeszentralamt für Steuern, BZSt).
- How you get it
- Automatically after your address registration — no application needed.
- How it is delivered
- By ordinary post only. It is not sent online and not read out by telephone, for data protection reasons.
- Validity
- For life. No person receives more than one, and a number is never reassigned to somebody else.
- Legal basis
- Section 139b of the Fiscal Code (Abgabenordnung).
- Cost
- Free.
Why it arrives on its own
The residents’ registration offices are linked to the Federal Central Tax Office’s records. As soon as your address registration is complete, your data is transferred automatically, the number is issued and the letter goes to your registered address.
Which is exactly why your name must be on the letterbox. The letter is not handed over in person and it is not always forwarded.
Where to find it if you lost the letter
Before you apply for anything, look in the documents you probably already have:
- Your income tax assessment (Einkommensteuerbescheid), if you have ever filed a return.
- The annual wage tax statement (Lohnsteuerbescheinigung) your employer gives you.
- The original letter from the Federal Central Tax Office, if you kept it.
How to have it sent again
- Use the online input formThe Federal Central Tax Office provides a form on its website for requesting that the number be re-sent. You fill in your personal details and your registered address.
- Or send a written request by postTo: Bundeszentralamt für Steuern, Referat St II 3, 11055 Berlin.
- Wait for the answer by postThe number will only ever be sent to your officially registered address. The office publishes no fixed processing time, so file the request early and do not build a tight deadline around its arrival.
Nobody will tell you your number by phone. You can call the Federal Central Tax Office on +49 228 406-1240, Monday to Friday, to ask about the status of your request — but the law prevents them from reading the number out over the telephone. Anyone offering to “get your tax ID online instantly” for a fee is either a middleman you do not need or an attempted scam: the service is free and delivery is by post only.
Do not confuse it with the other numbers
- Steuer-Identifikationsnummer (IdNr) — eleven digits, personal, permanent for life. This is the one this page is about.
- Steuernummer — issued by your local tax office (Finanzamt), tied to your tax file, and it changes if you move into another tax office’s district.
- Sozialversicherungsnummer — the social insurance number. A completely different body and a completely different purpose.
Official sources
Federal Central Tax Office — the tax identification number · Section 139b Fiscal Code
Please note: this page is general guidance, not tax or legal advice. Consult the competent authority or a licensed tax adviser in special cases.
Frequently asked questions
What is the German tax ID?
An eleven-digit number issued to you once for life, which does not change when your address, job or marital status changes. It is governed by Section 139b of the Fiscal Code and issued by the Federal Central Tax Office.
How do I get a tax ID?
You do not apply for it. It reaches you automatically by post once your address registration is complete, because the registration offices are linked to the Federal Central Tax Office’s records. For that reason your name must be on the letterbox.
Where do I find my tax ID if I lost the letter?
Look first in documents you may already have: your income tax assessment if you have ever filed a return, the annual wage tax statement from your employer, or the original letter from the Federal Central Tax Office.
How do I have the number sent to me again?
Through the online input form on the Federal Central Tax Office website, or by written request by post to Bundeszentralamt für Steuern, Referat St II 3, 11055 Berlin. It will only be sent to your officially registered address.
Can I get my tax ID online instantly?
No. The law prevents the number being read out by telephone, and delivery is by post only. Any website offering to “get your tax ID online instantly” for a fee is either an unnecessary middleman or an attempted scam — the service is entirely free.
What is the difference between Steuer-ID and Steuernummer?
The Steuer-ID is a personal eleven-digit number, permanent for life. The Steuernummer is issued by your local tax office, is tied to your tax file, and changes if you move into another tax office’s district. Both differ from the social insurance number.