イギリス向けおすすめeSIM

Until 2020 the UK sat inside the EU's roam-like-at-home rules. It doesn't any more. The confusing part is that operators reacted differently: some European carriers still include the UK in their Europe bundle as a commercial choice, and others pulled it out and charge separately.

There's no rule that covers everyone, so the only reliable answer is to check your own plan before flying. If your operator charges, an eSIM is almost always cheaper; if it's included, you don't need anything.

A week in London with transport, maps, digital tickets and some video: 3 GB is plenty. Wi-Fi is everywhere — pubs, coffee chains, Tube stations, many buses — and absorbs a good share of the load.

If the trip involves driving in Scotland or Cornwall with navigation running, move to 1 GB per day. The calculator below the table adjusts to your actual days.

Install the eSIM before you leave. Free Wi-Fi at Heathrow and Gatwick works well, so you have a fallback — but arriving with data already live is better, particularly if you're ordering a taxi or catching the Elizabeth line straight off the plane.