What is the 13-digit tax number?

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Last updated on 2025-08-06.

The 13-digit tax number plays a central role in the tax identification of businesses and self-employed individuals in Germany. It is issued by the respective tax office and is used to clearly assign all tax-related matters – from income tax to VAT.

Structure of the tax numberSince the introduction of the ELSTER system, the tax number consists of 13 characters. It is made up of several components:

Tax office number (2–3 digits): The final digits of the code assigned to the responsible tax office

District number (3–4 digits): Length varies depending on the federal state

Identification number (3–4 digits): A unique sequence to distinguish between taxpayers

Control digit (1 digit): Used to detect errors

❗ Note: The exact structure can vary by the federal state. In North Rhine-Westphalia, for example, the district number consists of 4 digits and the identification number of 3 digits – in other states, it’s the other way around.

With the BMF’s tax number converter, a state-specific tax number can easily be converted into the standardized 13-digit ELSTER tax number.