Mechnacz was formerly part of the German Empire. In the German Empire, the place was called Helmsdorf.
The place is now called Mechnacz and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Helmstorf | German Empire | Schubin | before the Versailles Treaty |
| Mechnacz, Folwark | Poland | Szubin | after the Versailles Treaty |
| Helmsdorf | German Empire | Altburgund | 1939 |
| Mechnacz | Poland | Szubin | 1945 |
| Mechnacz | Poland | Bydgoszcz | 1992 |