An important step to complete your registration is submitting your Tax ID (Steuer-ID). Your registration cannot be completed, and you cannot begin receiving new customer offers without this submission.
1. What is a Steuer-ID?
It is a unique, personal 11-digit tax identification number issued by the Bundeszentralamt für Steuern (BZSt), the German Federal Central Tax Office. It generally remains the same throughout your lifetime, even if you move or change employers.
Important: It is not your Gewerbeanmeldung number.
2. Where can I find this number?
After completing your Anmeldung (registration of your residence), the BZSt normally sends it by post to your registered address in Germany.
You can also find it on:
the letter from BZSt, entitled: "Mitteilung über die Zuteilung der Identifikationsnummer,"
your Einkommensteuerbescheid
or often on your Lohnsteuerbescheinigung from an employer.
Please don't confuse it with your Steuernummer – that's a different number from your local Finanzamt and can change over time.
Take a look at this sample letter from BZSt
Image Credit: https://www.bzst.de/
For more information about your Steuer-ID, you may also visit BZSt webpage.