Why use an eSIM in Switzerland?
Switzerland is the country where roaming bills go wrong. It sits outside the EU, so the roam-like-at-home rules that cover neighbouring France, Germany and Italy stop at the border, and many home-carrier packs either exclude it or charge a separate, higher daily rate. That matters on a trip that is navigated almost entirely by phone: SBB Mobile for train times, the Swiss Travel Pass on your screen, the Jungfraujoch webcam before you commit to the ticket, and Google Maps in Zurich, Lucerne and Interlaken. Buying a local prepaid SIM means finding a Swisscom, Sunrise or Salt shop and registering it against your passport, which Swiss law requires. A data eSIM removes the whole question. Install it at home, land at Zurich (ZRH) or Geneva (GVA), and the plan connects on the walk to baggage reclaim. Your home number stays alive in the other slot for calls and banking codes, while the eSIM carries every map, timetable and photo upload.

