Tandslet was formerly part of the German Empire. In the German Empire, the place was called Tandslet.
The place is now called Tandslet and belongs to Denmark.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Tandslet | German Empire | Sonderburg | before the Versailles Treaty |
| Tandslet | Denmark | Sønderborg | after the Versailles Treaty |
| Tandslet | Denmark | Sønderjylland | 1993 |