Your German tax ID (Steuerliche Identifikationsnummer)

1. You register your main or only home at the registration office (in Berlin, the Bürgeramt).
2. The registration office passes your data to the BZSt.
3. The BZSt assigns your number and sends a letter (Mitteilungsschreiben) by post to your registered address.

Many newcomers receive it within a few weeks; Freie Universität Berlin's welcome service, for example, tells new staff to expect about two weeks. Put your surname on the mailbox; the BZSt points out that the letter can only be delivered if it is there.

If it has not arrived three months after registering, send the BZSt a copy of your identity document and your registration confirmation (Meldebestätigung). The BZSt then checks with the registration office and sends you the number.

The number is only ever sent by letter. For data-protection reasons the BZSt does not give it out by phone or email, and it will only send it to an address other than your registered one if you give written authority with a copy of your ID.

• Your employer, together with your date of birth, to retrieve your electronic payroll tax data (ELStAM), such as your tax class. Employers must also print your tax ID on your payslips.
• Banks, which are required to record the tax ID of account holders, and investment providers if you set up a tax-free allowance order (Freistellungsauftrag).
• The family benefits office (Familienkasse) for child benefit, as well as health insurers and pension bodies, which report data to the tax authorities.
• The tax office for your tax return, and ELSTER, the tax administration's online portal. Registering for an ELSTER account normally uses your tax ID or tax number.

Treat the number as confidential and give it only to organisations that need it for these purposes. Its use is restricted by law.

Many people start a job before their tax ID arrives. The law (EStG § 39c) deals with this:

• If the delay is not your fault, your employer must work with the tax class you are expected to have, for up to three calendar months. Once the tax ID arrives, earlier months are reviewed and corrected in a later payslip.
• If you still have not given your employer the number after three months, or if you withhold it through your own fault, the employer has to apply tax class VI, the class with the highest deductions. For the three-month period this is then applied retroactively.

Tell HR or payroll that you have registered and are waiting for the letter, and pass the number on as soon as it arrives. Tax overpaid can usually be recovered through payroll corrections or your tax return.

Look first in:

• any payslip (employers must show it);
• your annual payroll tax certificate (Lohnsteuerbescheinigung);
• an income tax assessment (Einkommensteuerbescheid).

If you still cannot find it:

• Online: use the BZSt request form for a new notification. You need your name, registered address, date and place of birth, spelled as in your ID. The BZSt says processing can currently take up to four weeks (as of October 2026). The letter goes to your registered address.
• By letter: write to Bundeszentralamt für Steuern, Referat St II 7, 11055 Berlin, with the same details.
• Urgent cases: Berlin's service portal notes that you can ask in person at your tax office (Finanzamt), showing a valid identity document.

You never receive a new number. The BZSt only tells you the one you already have. You can also file a tax return without the number; your tax office already knows it or can look it up.

Three different numbers are easily confused:

• Tax ID (Identifikationsnummer, IdNr). 11 digits, from the BZSt, assigned automatically after your first registration, the same for life. It identifies you as a person.
• Tax number (Steuernummer). Assigned by your local tax office to a tax case, usually when you file your first tax return, or when you register a business or freelance activity. Self-employed people register with the Fragebogen zur steuerlichen Erfassung, submitted electronically through ELSTER. Its format depends on the federal state and the tax office, and you may get a new one if you move to an area covered by a different tax office. ELSTER warns against mixing it up with the tax ID.
• Social security number (Sozialversicherungsnummer, also called pension insurance number or Versicherungsnummer). Issued by the German pension insurance (Deutsche Rentenversicherung), not by the tax authorities. It has 12 characters (eight digits, one letter, three digits). You normally receive it automatically when you start your first job subject to social insurance, together with a Versicherungsnummernachweis, which replaced the old social insurance card in 2023. You give it to each new employer.

When a form asks for your Steuer-ID or IdNr, it means the 11-digit tax ID. Steuernummer means the number from your tax office.

• Not registered in Germany but working here (for example, cross-border commuters or short-term workers living abroad). The tax office responsible for the employer's business premises (Betriebsstättenfinanzamt) arranges the tax ID on application, using form 010250 (Antrag auf Vergabe einer steuerlichen Identifikationsnummer für nicht meldepflichtige Personen durch das Finanzamt). The number is sent to your address abroad.
• Children. Babies born in Germany receive their own tax ID by post once the registration office has passed on the birth data. Children living abroad are not assigned one. Since mid-2024 a child's tax ID is no longer mandatory in the child section of an electronic tax return on ELSTER.
• Leaving Germany. Your tax ID stays valid. Keep the letter; you may need it for a final tax return or if you return.