What is the Steuer-ID (tax identification number) and how do I get it?

The Steuer-ID (steuerliche Identifikationsnummer, IdNr) is an 11-digit personal tax number that stays the same for life. It identifies you to the tax authorities and is used by employers, banks, health insurers and the tax office.

How you get it: you do not apply for it. After your first address registration (Anmeldung) the registration office transmits your data to the Federal Central Tax Office (Bundeszentralamt für Steuern, BZSt), which assigns the number and sends it by post to your registered address, normally within a few weeks. Keep the letter; the number is also printed on later tax documents and on the electronic wage tax certificate from your employer.

If the letter does not arrive within about three months, or you lost it, you can request a new notification from the BZSt online (form "Mitteilung der IdNr"); the number is again sent by post, never by e-mail or phone. Make sure your name is on the letterbox, because the letter is not forwarded if it cannot be delivered.

When you need it:

• when starting a job (otherwise the employer withholds tax at the highest class until the number is provided and corrects it later);
• for the annual tax return (ELSTER);
• for some bank accounts, scholarships and child benefit.

Do not confuse it with the Steuernummer, which the local tax office assigns for self-employed activity or when you file a return, and which can change when you move.

Source: Bundeszentralamt für Steuern (bzst.de), § 139b Abgabenordnung.