Many people generally ask, “What is an eSIM?” An eSIM is a digital SIM embedded directly into your smartphone that replaces physical cards. For UK travellers, it works by downloading international data profiles onto the device via a QR code, granting instant abroad connectivity at local rates while keeping your main UK phone number active.
You can purchase a mobile plan online and activate the service within minutes without waiting for a physical chip in the post. This allows you to avoid expensive international roaming fees from major UK networks while staying reachable for calls and messages on your primary line.
The odd thing is, eSIMs have been around for over ten years, yet most of us only started hearing about them recently. A CCS Insight survey in January 2026 found nearly three-quarters of UK consumers now know what an eSIM is, up from 27% in 2022. One in four have used one while on holiday.
- No plastic card. It’s a chip embedded in your phone, so it can’t be lost.
- EE, Vodafone, O₂ and Three all do eSIMs, plus loads of smaller networks.
- Dial *#06#. See an EID number? You’re compatible.
- Outside Europe, roaming can be £15 a day. A travel eSIM costs far less.
What Is An eSIM?
The “e” stands for embedded. It does everything your old SIM did, like calls, texts, and data, but it’s all software. Rather than posting a card, your network sends a profile that downloads onto a tiny chip already inside your phone.
You can’t take that chip out, but you can delete a profile and install another. That’s how you switch networks now, straight from settings.
How Does An eSIM Work?
Your phone stores the network’s encrypted details in a secure part of the chip. Land in Bangkok and it scans for local masts, then logs on with those keys. Three sums it up well: An eSIM does the same job as a normal SIM, without the hardware faff. Coverage matches a local customer’s.
Is Your Phone eSIM UK Ready?
Most iPhones since the XS and XR handle eSIMs, so anything from around 2018 onwards. Pixels have supported them about as long, and Samsung’s flagship Galaxy phones joined from 2020. Tablets and watches count too – iPad 7th generation, iPad Air 3, iPad mini 5, and Apple Watch Series 4 and later.
Not sure? Dial *#06#. If a box appears with an Embedded Identity Document (EID) number, you’re sorted. Your phone must be unlocked too. Some newer kit gives no choice, as O₂ explains, the iPhone 17 Air and M5 iPad Pro have no SIM tray at all.
Which UK Networks Offer eSIMs?
All four big networks, plus a growing pile of smaller providers piggybacking on them. Getting one isn’t always simple, mind. Tesco Mobile makes you order a plastic SIM and convert it after, and some pay-as-you-go tariffs are the same.
ALSO READ: Top 5 Most Visited Countries That Will Never Disappoint Travellers
Swapping Your Current SIM For An eSIM
Already on pay monthly with one of the big four? Ask them to switch you. They’ll email or post a QR code; you scan it and follow the prompts. Usually instant, sometimes a few hours. Your contract shouldn’t change.
Apple users get an easier ride. With Three, iPhone owners skip the QR code and connect to Wi-Fi, then follow the on-screen steps. Android users get a code emailed over.
Why Travellers Save Money Abroad
Money Saving Expert points out that roaming add-ons outside Europe can cost up to £15 a day, depending on your provider and destination. Buy a travel eSIM before you fly and you’ll often pay less than that for a fortnight.
Best part: it sits alongside your UK SIM. You keep your number, still get calls and texts, and use WhatsApp or FaceTime for the rest.
| Destination | UK Carrier Daily Rate | 10-Day Cost (UK SIM) | Typical Travel eSIM Data Plan | Travel eSIM Cost | Estimated Savings |
| United States | £8.00 / day | £80.00 | 10 GB (30 Days) | £13.00 | £67.00 (83%) |
| Turkey | £7.86 / day | £78.60 | 10 GB (30 Days) | £11.00 | £67.60 (86%) |
| Thailand | £8.00 / day | £80.00 | 10 GB (10 Days) | £9.50 | £70.50 (88%) |
| Japan | £8.00 / day | £80.00 | 10 GB (30 Days) | £12.50 | £67.50 (84%) |
| UAE (Dubai) | £8.00 / day | £80.00 | 5 GB (30 Days) | £14.00 | £66.00 (82%) |
Source: Major UK Carrier Out-of-EU Roaming Tariffs & Global Travel eSIM Provider Pricing (2026)
Heading to Europe for a week? Don’t bother. O₂ still bundles EU roaming into most tariffs with a 25GB cap, and the rest charge a couple of quid a day.
How To Buy And Install One
Work out where you’re going, how long for, and how much data you’ll use. A weekend needs 1–3 GB and a week 5–10 GB. Streaming for a fortnight? Go for 15–30GB or unlimited.
According to the industry comparisons, Airalo, Holafly and Ubigi are the big names, while SimOptions, eSIMfy and eSIMdb compare dozens more. There’s a free option too — Firsty gives unlimited roaming data across 120 countries globally, including the USA, Australia and Japan, if you don’t mind ads. Check which local network your provider uses first, as coverage can be patchy on the wrong one.
- iPhone: Settings → Mobile Data → Add eSIM → Use QR Code, or enter details by hand. Type in what your provider sent, then pick whether it handles data, calls or both.
- Google Pixel: Settings → Network & Internet → SIMs → Add SIM → Set up an eSIM. Tap “Use activation code instead” and type your details in.
- Samsung: Settings → Connections → SIM manager → Add eSIM. Choose “Enter activation code”, then pop in the SM-DP+ address and code. You’ll need Wi-Fi throughout.
The Step Everyone Gets Wrong
Make the travel eSIM your default for mobile data, then switch data roaming on for that profile. Sounds backwards, but without roaming it can’t reach local masts. Now switch data roaming off on your UK SIM and turn off automatic data switching. Leave that line on for calls if you like.
Timing counts too. Some eSIMs start the clock the moment you install them; others wait until you land. Read the small print first.
Benefits And Drawbacks
Setup takes minutes, no waiting for the postman. You can store eight profiles and run two lines at once on a dual-SIM phone, handy for work and personal and there’s no plastic in the bin. More secure, too, since nobody can pull it out and clone it.
Downsides? Older phones miss out, and eSIMs aren’t hacker-proof, so keep your software updated. GSMA Intelligence projects eSIMs will account for 76% of global smartphone connections by 2030 (55% mark is projected for ~2027).
When Your eSIM Plays Up
Toggle flight mode on and off. Still nothing? Pick the network manually and check your data hasn’t run out. Deleted it by accident? Your provider will send a fresh QR code, though some want ID or a shop visit. Codes work once only, so save a screenshot somewhere safe.
ALSO READ: Lexie Alford – Meet The Youngest Person To Visit Every Country In The World
FAQs
Q1. Is An eSIM Cheaper Than Roaming?
Outside Europe, nearly always. Inside Europe, your existing plan usually wins on short trips.
Q2. Will I Lose My UK Number?
No. The travel eSIM sits next to your normal SIM, so calls, texts and banking apps carry on as usual.
Q3. Do I Need Wi-Fi To Install An eSIM?
Yes. The profile downloads over the internet, so sort it before you fly.
Q4. Can I Use An eSIM For A Hotspot?
Yep, tethering works fine, though a few providers limit it to manage network load.
Q5. Does An eSIM Work With 5G?
It does. If your phone supports 5G, an eSIM connects just like a plastic SIM.
Q6. Does My Phone Need To Be Unlocked?
Yes. A locked handset won’t install another provider’s profile, so check first.
Sources & References
- Technology Extension Division. (2026, July 9). What exactly is a UK eSIM and how does it work.
- MoneySavingExpert. (2026). What is an eSIM.
- O₂. (2026). eSIMs and numbers.
- Wikipedia. (2026). eSIM. In Wikipedia.
Disclaimer: This article is provided for informational purposes only and does not constitute endorsement, promotion, or formal advice regarding mobile network services or eSIM providers. Network tariffs, compatibility, and roaming policies are subject to change by respective telecom operators. Readers are advised to verify all terms, specifications, and details directly with official provider sources and seek professional advice before making any purchasing decisions.
