ELSTER (Elektronische Steuererklärung) is the German tax administration's official online portal. You use it to file tax returns, the questionnaire for registering a new business, applications to change tax class and correspondence with the tax office.

Two-step registration for security

Tax data is particularly well protected. Registration takes place in two steps: part of your access data is sent by email, while the activation code is sent by letter to your registered address.

The certificate file (.pfx) and password

After you enter the activation code, the system generates a personal certificate file with the extension .pfx. You download it to your computer and use it together with your password every time you log in.

Backing up your certificate

If you lose the file or forget the password, access cannot be restored: you have to register again and wait for a new letter. Keep a copy of the .pfx file on a secure USB stick or in an encrypted cloud archive.

Communicating directly with the tax office

Your ELSTER account lets you send documents and applications straight to your tax file. Replies from the tax office arrive in the electronic mailbox in your account, which shortens waiting times.

What to check

  • Register at elster.de as soon as you receive your tax ID.
  • Wait for the letter with the activation code (usually one to two weeks).
  • Download the certificate file and keep a secure backup on an external drive.
  • Use one ELSTER account for both personal returns and business filings.

Example situation

A professional orders an ELSTER certificate, activates it seven days later with the code from the letter and files her tax return for the previous year entirely online.

Next step

Your ELSTER certificate is your key to the tax office; take good care of the .pfx file and its password.

Official information on this topic

Checklists and examples are organisational recommendations. Requirements depend on the procedure, the city and your situation; check them with the relevant office before you act. Please discuss legal and tax questions with an authorised professional.

This article was prepared with the help of AI. The example illustrates the approach and does not describe a client case.