Registered office (Sitz der Gesellschaft)
Also: Sitz, Satzungssitz, Firmensitz, statutory seat
In short
The registered office is the place in Germany that the articles of association specify as the company's seat. It determines the register court at which the GmbH or UG is registered.
Registered office (Sitz der Gesellschaft) explained
The GmbH is registered with the court in whose district it has its registered office (Sec. 7 (1) GmbHG). The registered office must be in Germany (Sec. 4a GmbHG), and a German business address is also entered in the commercial register (Sec. 10 (1) GmbHG). The actual administration does not have to be at the statutory seat. For corporation tax, the tax office responsible is the one in whose district the management is located (Sec. 20 (1) AO), which is not necessarily the tax office at the registered office. Moving the registered office is an amendment to the articles of association before a notary.