This guide applies exclusively to private individuals in Germany 🇩🇪 and Austria 🇦🇹. For other countries, please use the information provided by your local tax authority.
We need your Steuer-ID (Germany) or Steuernummer (Austria) because, under the EU directive DAC8, we are required to collect certain tax-relevant customer data and report it to the competent authorities. Most EU countries use similar tax identification numbers (TINs) to uniquely identify taxpayers and simplify national tax administration.
1. Germany
Which number is meant?
🇩🇪 Germany: Steuer-ID (IdNr.)
This refers to the German tax identification number (“Steuer-ID”, “IdNr.”).
Format: 11 digits (numbers only)
Example (fictional): 12 345 678 901
You can find more information about this at the Bundeszentralamt für Steuern.
Not to be confused with:
Steuernummer (issued by the Finanzamt; a different system)
USt-IdNr. (VAT ID; typically relevant for businesses)
Where can I find my Steuer-ID?
You can usually find your Steuer-ID in the following documents:
Einkommensteuerbescheid (top left next to “IdNr.”) – example image
Lohnsteuerbescheinigung (BZST)
In the ELSTER portal, under your account information: “Identifiziert mit Identifikationsnummer:”
If you cannot find your Steuer-ID in your documents, you can request it again via the BZSt. For data protection reasons, it is not provided by email or phone, but only by letter.
Official links (BZSt/ELSTER):
2. Austria
Which number is meant?
🇦🇹 Austria: Steuernummer
This refers to the Steuernummer (for private individuals in Austria).
Format: 9 digits (a nine-digit Steuernummer).
Example (fictional): 12-345/6789
Not to be confused with:
UID-Nummer (VAT ID; typically relevant for businesses)
Where can I find my Steuernummer?
Your Steuernummer is communicated to you in writing and is listed on official written documents (e.g., assessments, requests for additional information) (BMF PDF). You can find it here:
On your Einkommensteuerbescheid (top right next to “Ihre Steuernummer”) – example image
Via FinanzOnline: Log in with your access data or via ID Austria/Mobiltelefon-Signatur, then select “Konto (your first and last name)” → “Grunddaten”. You will find your Steuernummer at the very bottom.
Via the FinanzOnline hotline: You can request your Steuernummer by phone at 050 233 790 (Monday to Friday, 8:00–17:00). Have your social security number, your name, and your address ready. In most cases, the staff can provide your Steuernummer after identification.
Official links (BMF/FinanzOnline):
BMF information (BMF PDF)
FinanzOnline help (note “Grunddaten zur Steuernummer”) (FinanzOnline)
3. Other countries
This guide only covers Germany and Austria. If you are tax resident in another country, please use the official information provided by your local tax authority to find the correct tax identification number.
4. Mini FAQ
Why is Coinfinity asking for this number now?
Because DAC8 requires us to collect certain tax-relevant customer data. Without this information, some functions or services may not be available.
In Germany, I only found a Steuernummer. Is that sufficient?
No. In this context, the Steuer-ID / IdNr. (11 digits) is required, not the Steuernummer. (Minijob-Zentrale)
I don’t have any documents on hand. What should I do (DE)?
Request it again officially via the BZSt; it will only be communicated by letter. (BZST)
I don’t have a Steuernummer yet (AT). What should I do?
If you live in Austria, you can request your 9-digit tax ID (“Steuernummer”) from your local Finanzamt. Alternatively, you can request it via FinanzOnline.
5. Security note
Only enter your Steuer-ID/Steuernummer/Tax-ID where you can clearly identify the provider (e.g., in your logged-in account). Do not share this number via DMs with other people or on social media.