Finanzamt — Steuer-ID, Tax Return and ELSTER

Steuer-ID vs. Steuernummer

In Germany, there are two different tax numbers — which often causes confusion:

• Steueridentifikationsnummer (Steuer-ID): An 11-digit number that you keep for life. It is automatically sent to you by mail after registering with your local registration office (processing time: 2–4 weeks). Every person in Germany has exactly one.
• Steuernummer: Assigned by your local Finanzamt when you file a tax return or register a business. Format: XXX/XXX/XXXXX. Changes if you move to a different Finanzamt district.

For employment your employer needs your Steuer-ID — not your Steuernummer. Without a Steuer-ID, your salary will be taxed at Steuerklasse 6 (highest deduction).

When is a tax return mandatory?

You must file an income tax return if:

• You and your spouse have Steuerklasse 3/5
• You received replacement income above €410 (sick pay, short-time work allowance, parental benefit, unemployment benefit I)
• You had additional income above €410
• You worked for multiple employers simultaneously
• The Finanzamt requests you to file

Even without a requirement, filing voluntarily is worthwhile: the average refund is €1,095.

ELSTER — the online tax office

ELSTER (Elektronische Steuererklärung) is the free online portal of the tax administration:

• Website: elster.de
• Registration: Takes approximately 2 weeks (activation code sent by mail)
• Features: File tax returns, retrieve tax notices, manage deadlines

Tip: Register with ELSTER immediately after receiving your Steuer-ID — then everything will be ready when you file your return.

Deadlines

Example: For tax year 2025, the deadline without an advisor is July 31, 2026.

Tax classes for foreigners

After registering and starting work, you will be assigned to a Steuerklasse:

• Class 1: Single, divorced, widowed — standard
• Class 3/5: Married, one partner earns significantly more (3) than the other (5)
• Class 4/4: Married, both earn similarly
• Class 6: Second job

Change: You request a Steuerklasse change at the Finanzamt — multiple changes per year have been possible since 2020.

As of: March 2026. All information without warranty.