The short answer
There are three ways to have mobile data abroad. A travel eSIM bought before you fly, your own network’s roaming, or a local SIM bought at the destination. Across the 20 countries priced below on 26 August 2026, a travel eSIM costs between $1.10 and $3.40 per gigabyte. Roaming costs a flat £2.72 a day on EE, £2.75 on Vodafone UK, or $12 a day on Verizon and AT&T. A local SIM is usually cheaper again, and usually not worth the queue.
Which one wins depends almost entirely on what your own SIM already gives you for free.
| If this is you | Buy this | Because |
|---|---|---|
| EU or EEA SIM, travelling in the EU or EEA | Nothing | Roam Like at Home applies at your domestic price until 2032 |
| O2 UK, travelling in its Europe Zone | Nothing | Included up to 25 GB, then £3.50 per GB |
| T-Mobile US on Experience Beyond | Nothing | 15 GB of high-speed data in 215+ destinations is in the plan |
| EE, Vodafone or Three UK, trip to Europe of 4 days or more | eSIM | £2.72 a day passes a $9 to $12 eSIM in three or four days |
| Verizon or AT&T, any trip of 2 days or more | eSIM | $12 a day is beaten by almost every eSIM on the second morning |
| Staying over three weeks, or you need a local number | Local SIM | Top-ups, a real number, and unlimited tiers a travel eSIM will not sell you |
What are we comparing on?
Five criteria, set before the prices, so the verdict is not reverse-engineered from whichever option happened to be cheapest.
- Price per gigabyte, measured at a 10 GB plan size.
- Whether you keep a working phone number.
- Setup effort, before departure and on arrival.
- What happens when the data runs out mid-trip.
- Whether the option works on your handset at all.
Price is the only criterion an eSIM wins outright. On the other four it either ties or loses, and the gap is wider than the marketing suggests.
What does an eSIM cost in 20 countries?
The figures below are Airalo’s own local packages, read from its product pages on 26 August 2026, in US dollars. Airalo is not the cheapest provider in every market. It is used here because it publishes a price for every country in one format, which is what makes a 20-country ranking possible.
| Country | 5 GB / 30 days | 10 GB / 30 days | Cost per GB |
|---|---|---|---|
| Portugal | $9.00 | $11.00 | $1.10 |
| Thailand | $8.00 | $11.00 | $1.10 |
| Spain | $9.00 | $14.00 | $1.40 |
| Turkey | $10.00 | $15.50 | $1.55 |
| Germany | $11.50 | $16.00 | $1.60 |
| Japan | $11.00 | $18.00 | $1.80 |
| Vietnam | $11.00 | $18.00 | $1.80 |
| Australia | $11.00 | $18.00 | $1.80 |
| France | $12.00 | $19.00 | $1.90 |
| Italy | $12.00 | $19.00 | $1.90 |
| United Kingdom | $13.00 | $19.00 | $1.90 |
| South Korea | $11.00 | $19.00 | $1.90 |
| Greece | $12.00 | $20.00 | $2.00 |
| United Arab Emirates | $12.00 | $20.00 | $2.00 |
| Indonesia | $13.50 | $21.00 | $2.10 |
| United States | $13.50 | $22.50 | $2.25 |
| India | $14.00 | $24.00 | $2.40 |
| China | $15.50 | $26.50 | $2.65 |
| Egypt | $20.00 | $33.00 | $3.30 |
| Morocco | $22.00 | $34.00 | $3.40 |
The spread is the useful part. Morocco and Egypt charge three times what Portugal and Thailand charge for the same gigabyte, because wholesale access in North Africa is expensive and the reseller passes that on. In the cheap markets the 10 GB plan is barely more than the 5 GB one, so buying the larger size costs almost nothing and removes the risk of running dry on day nine.
What does roaming actually cost?
| Network | Where | Price | Limit |
|---|---|---|---|
| Any EU or EEA SIM | EU and EEA, plus Ukraine and Moldova from 1 January 2026 | Your domestic price | Operator fair-use cap, notified in advance |
| O2 UK | Europe Zone, 48 destinations | Included | 25 GB, then £3.50 per GB |
| EE | EU zone | £2.72 a day | Charged per UK day, midnight to midnight UK time |
| EE | Outside EU, EEA and Switzerland | £6 for 24 hours in ROW Zone 1, £8 in Zone 2 | Data needs a pass. There is no pay-per-MB fallback |
| Vodafone UK | Zone B, 52 destinations | £2.75 a day | 25 GB fair use |
| Three UK | Go Roam in Europe | £2 a day, £2.75 if you joined from 18 December 2025 | 12 GB a month |
| Three UK | Go Roam Around the World | £7 a day, £8 from 1 April 2026 | 12 GB a month |
| Verizon | 210+ destinations | $12 a day, $6 in Canada and Mexico | 5 GB at full speed, then 3G |
| AT&T | 210+ destinations | $12 a day, $6 per extra line | Never more than 10 daily fees per line per bill |
| T-Mobile US, Experience Beyond | 215+ destinations | Included | 15 GB at full speed, then 256 kbps |
Two numbers decide most trips. A UK daily charge of about £2.72 means a $12 eSIM pays for itself somewhere on the fourth day. A US daily charge of $12 means it pays for itself on the second. AT&T’s cap of ten daily fees per line is the one piece of good news in the American column: a three-week trip costs $120, not $252.
Note what EE’s price guide does outside Europe. Data is not sold by the megabyte at any price. Without a Rest of World pass there is no data, so the £6 or £8 daily figure is the floor, not an option you can undercut by using less.
When does a local SIM still win?
A local SIM wins on three things a travel eSIM cannot do. It gives you a local number, which delivery apps, ride-hailing accounts and some hotel booking confirmations still demand. It can be topped up in any convenience store when the allowance runs out. And on long stays it is simply cheaper, because you are buying at resident prices rather than wholesale-plus-margin.
In the UAE, du gives arriving visitors a free prepaid SIM with 1 GB valid for 24 hours at Dubai airport immigration, and sells a 90-day Tourist Plan SIM for AED 55, around $15. That undercuts the $20 eSIM and hands you a number as well.
Against that, you queue on arrival, you hand over your passport for registration in most countries, and you swap out your home SIM unless your phone holds two. For a five-day city break the saving is a few dollars and the cost is half an hour at the end of a flight. That is a bad trade. Past about three weeks it flips.
What goes wrong
- Your phone is carrier-locked. A travel eSIM needs an unlocked, eSIM-capable handset. Apple supports eSIM from the iPhone XS, XS Max and XR onwards. Two eSIMs at once work from the iPhone 13 and the iPhone SE third generation. If the phone is locked to a network, none of this applies and roaming is your only option.
- You expect a phone number. Airalo’s local packages are data-only. No local number, no SMS, no voice. Bank verification codes will not arrive on it.
- You leave data roaming on. Install the eSIM, set it as the data line, and switch data roaming off on the home line. Leaving both on is how a UK daily charge gets triggered by a background sync you never saw.
- You arrive at 11pm on EE. The daily charge is applied for a UK day, midnight to midnight UK time, not for a rolling 24 hours. One late-evening email costs a full day.
- You install the eSIM at the airport on arrival. Install it at home on Wi-Fi. The QR code and the profile download need a working connection, which is exactly what you do not have yet.
- You stay in Turkey more than 120 days. Turkey’s BTK blocks unregistered foreign handsets after 120 days from entry. It never bites a normal trip. It bites long-stayers hard.
- You assume the headline rate is the bill. The same gap between advertised price and final total shows up in car hire, and it is worth checking both before you travel.
Frequently asked questions
Can I keep my normal number while using a travel eSIM? Yes, on a dual-SIM phone. Keep the home SIM active for calls and texts, set the eSIM as the data line. Receiving a call in EE’s EU zone costs nothing on its published rates, and the daily charge is described as applying when you use your plan allowances.
Do travel eSIMs allow tethering? Airalo says yes, over Wi-Fi, Bluetooth or USB, with no extra fee, limited only by the data you bought. Not every provider matches that, so check before you rely on it for a laptop.
Is an eSIM worth it inside the EU if I have an EU SIM? No. Roam Like at Home gives you your domestic allowance at no surcharge across the EU and EEA, and from 1 January 2026 in Ukraine and Moldova too. Buying data you already have is a waste.
What happens when the eSIM data runs out? The connection stops. Most providers sell a top-up in the app, but you need a connection to buy it, which usually means finding Wi-Fi. This is the single strongest argument for buying the 10 GB plan when it costs $2 more than the 5 GB one.
Will an eSIM work in China? A local China eSIM connects, at $2.65 per GB. Whether it routes around the national firewall depends on which operator the profile lands on, and no provider guarantees it. Plan for a VPN and do not treat access to any specific service as certain.
Is Airalo the cheapest? Often not. Regional and unlimited-tier providers undercut it on longer trips. It is used here as a consistent yardstick across 20 markets, not as a recommendation.
Sources: European Commission, roaming policy; Regulation (EU) 2022/612; EE Plan Price Guide, charges applicable from 31 March 2026; Three UK, Go Roam; Vodafone UK, roaming zones; O2 roaming fair usage terms; Verizon TravelPass; T-Mobile international roaming plans; Airalo country package pages; Apple, using Dual SIM with an eSIM; BTK, central device registration system; du Tourist SIM; ECB euro reference exchange rates, 26 August 2026.
Researched from primary sources and checked August 2026. General information, not advice.
