As long as your phone supports 3G and 4G networks, your phone should be compatible in Switzerland.
However, we can’t guarantee this accounting as our customers use European versions of smartphones. Moreover, if you plan to travel in Europe with your foreign smartphone (especially American), we are not able to guarantee that the frequency bands are compatible for 3G/4G. It is therefore not excluded that your calls will not work in some European countries.
ID: FAQ_EXT-05_10065_1question