When Bydgoszcz joined back Polish territory in 1920, Prussian administration was liquidated, the now disused building housed, among others, the Regional Directorate of State Forests, the Accounting Chamber of Control of the Ministry of Posts and Telegraphs, the Regional Tax Office, the county School Inspectorate and the Inspectorate of Labour. In 1938, Bydgoszcz city became the capital of Pomeranian Voivodeship and the building housed its administrative services. During the Nazi occupation, German authorities reactivated Bydgoszcz "Rejencja" within the District of Gdańsk-West Prussia and used the edifice accordingly.
