Germany gives you several different numbers. Mixing them up is the most common newcomer mistake.
| Number | Format | Issued by | When | Used for |
|---|---|---|---|---|
| Steuer-ID (Steuerliche Identifikationsnummer) | 11 digits, lifelong | Bundeszentralamt für Steuern (BZSt) | Automatically, 2–4 weeks after first Anmeldung | Payroll, Kindergeld, bank (Freistellungsauftrag), all tax matters |
| Steuernummer | Varies by state, e.g. 21/815/08150 | Your local Finanzamt | After your first tax return or when self-employed | Correspondence with the Finanzamt, invoices for freelancers |
| Wirtschafts-ID / USt-IdNr. | DE + 9 digits | BZSt | Businesses only | EU invoicing |
| Sozialversicherungsnummer (Rentenversicherungsnummer) | 12 characters, e.g. 65 170839 J 003 | Deutsche Rentenversicherung | When your employer first registers you | Employer, pension, Krankenkasse |
| Krankenversichertennummer | Letter + 9 digits on the eGK | Your Krankenkasse | On joining | Doctors, pharmacies |
If the tax ID does not arrive
- Check that your name is on the letterbox — letters are not re-sent automatically.
- Request it again with the online form on bzst.de ("Steuer-ID anfragen"). For data-protection reasons it is sent only by post to your registered address, never by phone or email.
- Some Bürgerämter can print the number on the spot when you register — ask.
- Until your employer has it, you are taxed in class VI. The extra tax is refunded automatically through payroll correction or the tax return.
Social security number
- Your employer registers you, and the Rentenversicherung posts you a letter with the number.
- If you need it faster (for example, for a second job), call the Deutsche Rentenversicherung or apply online.
Keep a "numbers card"
Store in your password manager: Steuer-ID, Steuernummer, SV-Nummer, Krankenversichertennummer, IBAN, Rundfunkbeitrag number, Ausländerbehörde case number (Aktenzeichen). Every letter you send should quote the relevant number.
Official sources: bzst.de · deutsche-rentenversicherung.de