5 mistakes people make with their first travel eSIM
14 July 2026 · 4 min read
None of them are disasters, and all of them are avoidable. Read this before you fly and you'll skip the lot.
eSIMs are genuinely simple, but there are a handful of traps that catch people the first time. Here's how to dodge all of them.
1. Waiting until you land to install it
This is the big one. Installing an eSIM needs an internet connection — which is the one thing you haven't got when you've just stepped off a plane in a foreign airport.
Do this instead: install it at home, on wifi, before you travel. It sits there doing nothing until you arrive, then connects automatically.
2. Assuming your phone is unlocked
An eSIM is still a SIM, and a phone that's locked to one network won't accept it. If you bought your phone outright, or you've finished paying off a contract, you're almost certainly fine.
Do this instead: if you're not sure, ask your network. In the UK they have to unlock it free of charge, but it can take a day or two — so don't leave it to the night before.
3. Turning off your normal SIM
People panic and disable their everyday SIM, then wonder why they've stopped getting texts.
You don't need to. Leave your normal SIM switched on for calls and texts, and just set the eSIM as your data line. You keep your number and your messages; the eSIM quietly does the internet.
4. Leaving data roaming off for the eSIM
This one is genuinely confusing, because it sounds like exactly what you're trying to avoid.
Your travel eSIM connects to a foreign network — so, technically, it is roaming. It needs data roaming enabled on the eSIM line to work. That does not mean you'll get charged by your home network: your home SIM's data stays off, and the eSIM's data is already paid for.
Do this instead: in your phone's mobile data settings, pick the eSIM as the data line and allow data roaming on that line only.
5. Buying way more data than you need
It's tempting to buy 20 GB "just in case". Most people on a two-week trip use nowhere near that — maps, messaging and a bit of scrolling is light work.
Do this instead: start smaller. If you run out, top up in a couple of taps. Better to pay twice for what you used than once for what you didn't.
Get those five right and there's genuinely nothing else to it. Install before you fly, keep your normal SIM in, let the eSIM handle data — and land with full bars.