Do I need a travel eSIM?

You probably don't need one if you're on O2 pay monthly and going to the Europe zone, or your plan includes roaming (some Three, Vodafone and EE plans do), and you'll use less than your fair-use limit.

You probably do if you're paying a daily fee (£2–£3 a day in Europe, £6–£8 outside it), going to the USA, Turkey, Japan, Thailand or the UAE, or you need more data than your roaming fair-use limit.

Rule of thumb: multiply your network's daily fee by your trip length and compare it with a plan that covers your days and data. Use the checker on the travel eSIM page.