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