The ELSTER Tax Number is a specific standardized format for all federal states, which is 13 digits long. It consists of a four-digit federal tax office number (BUFA number), a binding zero and the remaining eight digits of the tax number.
Tax Number (German: "Steuernummer") at the tax office
The tax number from the correspondence with the tax office has different lengths and spellings according to the federal state.
The following example is from the federal state Bayern:
Translated to the ELSTER Tax Number format it equals:
For the list of all tax offices with BUFA No. see gemfa_xml_export_datei.zip in Tax offices
Checksum digit
The last digit of the ELSTER tax number is a checksum digit. It determines whether a tax number is valid. The algorithm is explained in chapter 6 of the official ELSTER documentation.
For the above mentioned ELSTER tax number only 0 (zero) is a valid checksum digit.
Tax identification number (German: "Steueridentifikationsnummer")
The eleven-digit tax identification number (abbreviated in German: "Steuer-ID") is issued by the Federal Central Tax Office (German: Bundeszentralamt für Steuern). Every taxpayer receives this number permanently. It does not change when the taxpayer moves.
It should not be confound with the tax number (German: "Steuernummer").
