If you want to use your phone abroad, you know the problem: your home network stops working, roaming charges are steep, and hunting for a SIM card at an unfamiliar airport costs time and patience. eSIM technology has changed that over the past few years — for many travellers it is now the simplest and cheapest way to get mobile data abroad.
What an eSIM actually is, which countries it makes the most sense in, and how the most popular providers compare — that is what this article covers.
Contents
What is an eSIM? Explained simply
An eSIM (embedded SIM) is a digital SIM card built into your phone. Instead of a physical card you have to insert and remove, you load a digital profile onto your device through an app or a QR code — much like installing an app. The profile holds everything a mobile network needs to recognise your device and supply it with data.
The decisive advantage: you can keep several eSIM profiles on your phone at once and switch between them. Your home SIM stays active for calls and texts while the eSIM handles local data. No fiddling with tiny plastic cards, no risk of losing your home SIM.
Which devices support eSIM?
Most current smartphones support eSIM — every iPhone from the XS (2018) onwards, the Samsung Galaxy S21 and newer, the Google Pixel 3 and newer, and many other Android devices. To check your own phone, open Settings and look under Mobile data or SIM: if Add eSIM appears, your device supports it.
eSIM vs. local SIM vs. roaming
| Ready to go | Home SIM stays active | Cost outside the EU | Catch | |
|---|---|---|---|---|
| 📱 eSIM | Immediately | Yes | Low | Device must support eSIM; no local phone number |
| 🛒 Local SIM | Buy on arrival | No | Lowest | Activation can be awkward; registration required in some countries |
| 🌐 Roaming | Nothing to do | Yes | Very high | Unpredictable bills, low data caps |
The short version: inside the EU, roaming has been free since 2017 — you pay the same as at home as long as you are in an EU or EEA country. The moment you leave (Thailand, Japan, the USA, Dubai, Australia), roaming costs explode. That is where an eSIM almost always wins.
Which countries do I need an eSIM for?
The rule of thumb: inside the EU you do not need one, because roaming is free. Once you cross the EU border it almost always pays off. That goes especially for:
- Thailand, Vietnam, Indonesia: roaming is extremely expensive, eSIM plans are very cheap
- Japan: local SIMs are hard to get (registration is often required), an eSIM is far simpler
- USA and Canada: roaming is expensive, eSIM coverage is excellent
- Dubai / UAE: calls over VoIP such as WhatsApp and FaceTime were blocked for years — a local eSIM gets around it
- Australia and New Zealand: long distances, good eSIM coverage in the cities
- Turkey and the UK: no EU roaming any more, so an eSIM pays off here in particular
Inside the EU roaming is free — you can use your home data allowance as if you were at home, up to a fair-use limit. You do not need an eSIM for France, Spain or Italy.
The exceptions are Turkey, the United Kingdom, Switzerland, Norway and several non-EU Balkan countries. Mobile data there gets expensive fast, and an eSIM is usually the cheaper choice — check your own roaming rate for those countries, they are billed like any other non-EU destination.
What roaming actually costs, and why an eSIM undercuts it
The honest answer to "how much does roaming cost" is: it depends entirely on your own contract, and the spread is enormous. What matters is how you are billed, not which country you are in.
| How your carrier bills you | Typical rate outside the EU | What 2 GB would cost |
|---|---|---|
| Day pass (UK carriers) | £5–£10 per day | Priced by days, not data — roughly £70–£140 for two weeks |
| Day pass (US carriers) | $10–$12 per day | Roughly $140–$170 for two weeks |
| Pay-per-use (EU carriers) | €0.99–€1.49 per MB | Over €2,000 |
| Pay-per-use (AT&T, Verizon) | $2.05 per MB | Over $4,000 |
| Travel eSIM | single-digit to low-double-digit euros per plan | Usually under €20 |
Rates checked September 2026. The pay-per-use rows are not a typo: at $2.05 per megabyte, two gigabytes really would cost more than the flight. That is the tariff you fall onto if you travel without a day pass and without checking — which is exactly why the one number worth knowing is your own carrier's. Look it up before you go.
Which provider should you buy?
The big four are Airalo, Holafly, Saily and Yesim. They are all reputable and all usable worldwide — they are built for different kinds of trip, which is why naming a single winner is not useful. We compare them properly in our travel eSIM comparison, including the four questions that actually decide it: which local network the plan uses, whether hotspot sharing is allowed, what "unlimited" means in the small print, and when the clock starts.
Download the provider's app, create an account and buy a data plan for your destination.
Install the eSIM profile — either by pointing your camera at the QR code and confirming, or straight from the app.
On arrival, switch the eSIM on in your settings. Done — no kiosk, no queue, no stress.
Frequently asked questions
Can I make calls with an eSIM?
Most travel eSIMs are data-only plans, so you call through WhatsApp, FaceTime or Signal over the data connection. If you need a local phone number you have to book one separately — Yesim offers this — or carry a local SIM alongside.
What happens when the data runs out?
Depending on the provider and plan, the connection is throttled or you top up directly in the app, usually active within a few minutes. That is considerably more convenient than finding the nearest phone shop.
Does eSIM work on older iPhones?
eSIM is available from the iPhone XS (2018) onwards. The iPhone 14 and newer US models have no physical SIM tray at all. Older iPhones (iPhone X and below) do not support eSIM.
Public Wi-Fi in hotels, cafés and airports is often unencrypted. A VPN protects your data and gives you the same security on the road that you have at home.
NordVPN encrypts your traffic on public networks and shields your passwords, banking apps and personal data from prying eyes. It runs alongside your eSIM and costs only a few euros a month on an annual plan.
Pros
- Protection on public Wi-Fi
- Up to 10 devices at once
- Fast servers worldwide
- 30-day money-back guarantee
Cons
- Paid subscription, cheapest on an annual plan
- Marginal effect on connection speed
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