Kupno was formerly part of the German Empire. In the German Empire, the place was called Kaufen.
The place is now called Kupno and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kupno | Russian Empire | Rypin | 1914 |
| Kupno | Poland | Rypin | after the Versailles Treaty |
| Kaufen | German Empire | Rippin (Westpr.) | 1939 |
| Kupno | Poland | Rypin | 1945 |
| Kupno | Poland | Toruń | 1992 |