Tax ID, tax number, VAT ID: which German number is which

Germany gives you up to four tax numbers, and they are not interchangeable. The Steuer-ID (11 digits) is personal and for life: it goes to your employer, your bank and on your tax return. The Steuernummer is your file number at your local Finanzamt; it changes if you move to another tax office's area, and it can go on invoices. The USt-IdNr (DE plus nine digits) is your EU VAT ID, for business with other EU countries, and can stand in for the Steuernummer on invoices. The new Wirtschafts-Identifikationsnummer (W-IdNr) is arriving in stages: nobody applies for one, and until the rollout is complete it is optional on tax forms.

1. The four numbers at a glance

2. The Steuer-ID: yours for life

Every person registered in Germany has one tax identification number, and only one (§ 139b(1) AO). It has 11 digits, says nothing about you, and stays the same through moves, marriage and name changes.

How you get it: automatically. When you first register an address (Anmeldung), the registration office passes your details to the BZSt, which sends the number by post. For people arriving from abroad it usually comes within days. Your surname has to be on the letterbox, or the letter may not be delivered. If nothing has arrived three months after registering, the BZSt asks you to send a copy of your ID and your registration certificate (Meldebestätigung).

Working for a German employer while living abroad, with no address to register? Then the employer's Finanzamt arranges the number, on form 010250.

Who may ask for it: the Finanzamt, and anyone who has to report data about you to it. Others may use it only for that reporting, where a law allows it, or with your consent (§ 139b(2) AO); misuse is a fineable offence. In practice that means your employer, banks, health and pension insurers and the Familienkasse ask for it. Clients don't need it, and it doesn't belong on an invoice.

3. The Steuernummer: your file at the Finanzamt

The Steuernummer is a file reference that your Finanzamt gives you for its own organisation. You can't apply for one; you get it when the Finanzamt registers you:

• employees and landlords with their first income tax return, leaving the field blank;
• freelancers and businesses after the tax registration questionnaire, as in our guide to registering as a freelancer.

It comes by post, and it is on every tax assessment after that. Its format depends on the state: 10 or 11 digits with slashes, and 13 digits in the federal format that some official letters use.

You can have more than one: a business often gets its own, next to the one for your personal income tax. Married couples assessed jointly share one. And it changes when you move into another Finanzamt's area: the new office gives you a new number.

4. The USt-IdNr: your business in the EU

The VAT identification number is issued by the BZSt (§ 27a UStG) to businesses that trade across EU borders: selling goods or services to businesses in other EU countries, or buying from them. It is DE followed by nine digits, and a business has one, however many activities it runs. It is for business only: using it for private purchases is not allowed.

How you get it: tick the box in the tax registration questionnaire, or, once the Finanzamt has registered you for VAT, apply online at the BZSt with your Finanzamt, Steuernummer, name and date of birth. The number comes by post, never by email or phone. Through the questionnaire it can take up to two months.

Small businesses under the VAT exemption (Kleinunternehmer) can have one too, for example to buy services from businesses in other EU countries.

5. The W-IdNr: where the rollout stands

The business identification number is meant to become the one number for everyone who is economically active: self-employed people, companies and partnerships (§ 139a and § 139c AO). It is DE and nine digits, plus a five-digit suffix for each activity, starting with -00001. After a transition period it is to replace the Steuernummer. The Steuer-ID and the USt-IdNr stay.

The BZSt hands it out in three stages, as its page stood on 10 September 2026:

• Stage 1, since November 2024: businesses that file an annual VAT return, and small businesses under the VAT exemption. That covers most freelancers and sole traders.
• Stage 2, from the fourth quarter of 2026: companies subject to corporation tax, such as a GmbH or UG, and partnerships that file a separate profit-determination return (Feststellungserklärung).
• Stage 3, from the fourth quarter of 2027: everyone still without one, plus further suffixes (-00002 and so on) for a second activity.

How it reaches you depends on whether you had a USt-IdNr on 30 November 2024:

• You did: your W-IdNr is your USt-IdNr with -00001 added. There is no letter; a public notice in the Federal Tax Gazette did the job.
• You didn't, or you started later: it arrives in your ELSTER mailbox, with an email to say so. It comes faster if you consent to electronic notification in ELSTER (Formulare und Leistungen → Einwilligung zur elektronischen Bekanntgabe, once per tax number); without that, it can take several months. If a tax advisor holds general authority to receive your post, it goes to them.

You can't apply for it, and you lose nothing by not having it yet: until the first allocation is finished, giving it on tax forms is optional. If an email about your W-IdNr looks odd, open your ELSTER mailbox directly; the BZSt says there is no need to click a link. For invoices nothing has changed: the law still asks for the Steuernummer or the USt-IdNr.

6. Which number goes where

On invoices, once you have a USt-IdNr you can use it instead of the Steuernummer; both are valid. More in our guide to invoice requirements.

On the employer: a new employee gives the Steuer-ID and date of birth so the employer can fetch the wage tax details electronically (§ 39e(4) EStG). If the number hasn't been issued yet through no fault of the employee, the employer works with the expected tax class for up to three months. If it is still missing after that, or the employee simply doesn't hand it over, tax class VI applies, back to the start (§ 39c(1) EStG).

7. Clients abroad

A business client in another EU country. A service for a business is generally taxed where the client runs its business (§ 3a(2) UStG), so the client accounts for the VAT, not you (the reverse charge). Your invoice then shows your USt-IdNr and the client's, carries the words "Steuerschuldnerschaft des Leistungsempfängers", and is due by the 15th of the month after the service (§ 14a(1) UStG). The same services go in a recapitulative statement (Zusammenfassende Meldung) to the BZSt, by the 25th day after the quarter (§ 18a UStG). The BZSt and the EU's VIES service let you check that a client's VAT ID is valid. Small businesses under the VAT exemption follow partly different rules: they don't file the statement, for one.

A client outside the EU. The USt-IdNr has no role there. A client who asks for proof that you are tax resident in Germany, for example to apply a tax treaty, needs something else: a certificate of residence (Ansässigkeitsbescheinigung) from your Finanzamt, on the other country's own form where it has one.

Where VAT gets complicated, such as goods, digital services to consumers or mixed clients, our guides to VAT returns and the small-business exemption go further.

8. If you've lost one, with a letter to copy

• Steuer-ID: look on your last income tax assessment or your annual wage tax certificate (Lohnsteuerbescheinigung). Otherwise the BZSt sends it again, on request through its online form or by letter, and only by post to your registered address. Nobody will give it to you over the phone. It is the same number as before, and a tax return can be filed without it: the Finanzamt can find it.
• Steuernummer: it is on every assessment and on the Finanzamt's letters. If you have none to hand, ask your Finanzamt.
• USt-IdNr: request it again through the BZSt's online form. You get a copy of the original notice by post; the number stays the same.
• W-IdNr: if you had a USt-IdNr by 30 November 2024, it is that number plus -00001. Otherwise it is in your ELSTER mailbox, or the BZSt sends it again through its form "Erneute Mitteilung der W-IdNr."

For the Steuer-ID, the online form is the quickest route. If you'd rather write, the letter below gives the BZSt the details it asks for, in German. Replace the parts in square brackets.

An das
Bundeszentralamt für Steuern
Referat St II 7
11055 Berlin

Betreff: Erneute Mitteilung meiner steuerlichen Identifikationsnummer

Sehr geehrte Damen und Herren,

bitte teilen Sie mir meine steuerliche Identifikationsnummer erneut mit. Meine Angaben:

Name: [Nachname]
Vorname(n): [Vorname(n)]
Geburtsdatum: [TT.MM.JJJJ]
Geburtsort: [Ort, Land]
Meldeanschrift (Hauptwohnsitz): [Straße Hausnummer, Postleitzahl Ort]

Mit freundlichen Grüßen
[Name]
[Unterschrift]

9. Numbers that aren't tax numbers

• Social insurance number (Versicherungsnummer, often called Sozialversicherungsnummer): from the Deutsche Rentenversicherung when you start your first job. A replacement certificate comes from the Rentenversicherung or your health insurer.
• Betriebsnummer: an employer's number for social insurance reporting, from the Federal Employment Agency's Betriebsnummern-Service. See our guide to hiring your first employee.
• Kleinunternehmer-Identifikationsnummer: for using the small-business VAT exemption in another EU country through the EU scheme (§ 19a UStG), also from the BZSt.

The short version

The Steuer-ID is you, for life. The Steuernummer is your file at your Finanzamt, and it follows your address. The USt-IdNr is your business in the EU. The W-IdNr is on its way, and there is nothing to apply for. When a form, a client or an employer asks for "your tax number", it is worth checking which of the four they mean.