A country plan works in that country. A region plan, such as Europe, works in every country it lists, on one eSIM. You don’t switch anything at the border.
Which to pick
- One country: its own plan is usually cheaper.
- Crossing borders, even for a day trip: a region that covers every country on your route.
Each destination’s page lists the countries it works in. Some country plans also work in nearby countries at no extra cost, and their page says so. To find the regions that include a country, type it into the search on Destinations.
You can’t switch later
A top-up adds data for the eSIM’s own destination. A Czechia eSIM takes more Czechia data, not Europe data. If your trip grows, you need a new eSIM for the region.