UK SIM Cards and eSIMs for Visitors: Every Option Compared

In this guide

Getting mobile data in the UK is cheap. Getting it without paying for a mistake is harder, because the choices that look alike are not.

A travel eSIM and a UK SIM card are different products. An eSIM from Saily, Nomad or Airalo is data only and has no UK phone number. A pay-as-you-go SIM from O2, Three or giffgaff gives you a +44 number and usually far more data for the money, but it comes with speed caps, age blocks and card problems that the eSIM companies spare you. And your home network’s roaming, at $12 a day on the big US carriers, is almost always the most expensive of the three.

This guide compares all of them, with every price taken from the provider’s own website in September 2026.

💡 The Short Version: On an eSIM phone for a week or two, buy EE’s Travel eSIM — unlimited data at full speed on the UK’s fastest network, £15 for 7 days, £20 for 14 days. If you only need a few gigabytes, Nomadad and Sailyad are cheaper. If you need a UK phone number, or you are carrying on to Europe, buy an O2 pay-as-you-go SIM — £10 for 8GB or £15 for 25GB, with up to 25GB of EU roaming included. Do not buy at the airport.

📘 How we checked (editorial note). Every price and allowance below was read from the provider’s own site on 14 September 2026. Links marked ad — Saily, Nomad and Klook — pay us a commission if you buy; they are not ranked above anything that does not, which is why EE’s own eSIM, which pays us nothing, is the first recommendation on this page.

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Which one should you get?

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The speed cap nobody mentions

The UK’s fastest network is EE, and most visitors who buy an EE SIM never get its speed.

RootMetrics’ testing in the first half of 2026 gave EE its 26th consecutive UK overall award and a UK-wide median download speed of 130.3 Mbps — more than twice Virgin Media O2 (54.7 Mbps), Vodafone (54.0 Mbps) and Three (48.1 Mbps). EE won every award in all 16 cities tested, London included.

But EE’s own pay-as-you-go plans say “Max speed of 25Mbps” on every tier, from £10 to £35. Three’s one-month data packs are capped at up to 25Mbps too, and its auto-renew packs at up to 50Mbps.

Twenty-five megabits is plenty for maps, messaging and social media. It is noticeably slow for video calls in HD, uploading video, or tethering a laptop.

The way round it is EE’s Travel eSIM, which EE sells as “uncapped speed”. It is the only way to get EE’s full network speed on a short prepaid plan. O2, Vodafone, giffgaff and Lebara do not publish a speed cap on their pay-as-you-go plans.

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Travel eSIMs compared

A travel eSIM is data only. You install it before you fly or on arrival, it runs alongside your home SIM, and you call and message over WhatsApp, FaceTime or iMessage. There is no UK phone number and no ordinary SMS. Emergency calls to 999 and 112 still work on EE’s.

Prices for a typical one-week trip:

EE Travel eSIM — the best value for most visitors

Unlimited data, uncapped speed, on EE, from the network itself.

You have 90 days from purchase to start using it, you do not need a UK address, and you can install it before you land. It is data only: on Android there are no SMS messages at all; on an iPhone, iMessage still works. EE refunds it within 90 days if you have not used it.

Two restrictions to know. Your phone must be unlocked. And every EE Travel eSIM has a “Moderate” content setting that blocks 18-rated sites and cannot be changed — see the section on content blocks below.

Buy it on EE’s website: ee.co.uk/mobile/travel-esim-uk.

Nomad — cheapest for a set amount of data

Nomadad runs on Three, O2 and Vodafone and has the lowest prices here for fixed data. Its site shows prices in pounds converted from dollars, so they move slightly with the exchange rate.

Read the unlimited small print. The 3-, 5-, 7- and 10-day unlimited plans give 2GB a day at 4G or 5G, then 1 Mbps for the rest of the day. The 30-day plan is sold as full-speed. Plans with minutes and texts included start at £9.61 for 5GB. You have 60 days after buying to start using the plan, and the unlimited plans are non-refundable.

Saily — the longest window to activate

Sailyad gives you 180 days to activate and switches the plan on automatically when you land.

Hotspot use is unrestricted, and Saily sells a separate US phone number with a calls-and-texts plan if you want one.

Airalo — the biggest name, and options with minutes

Airalo’s UK plans run on EE. Data-only prices are close to Saily’s: £7 for 3GB over 7 days, £14.50 for 10GB over 30 days, £30 for 50GB, and £21 for 7 days unlimited. Like Nomad, it also sells UK plans with calls and texts included — £11 for 5GB, 50 minutes and 50 texts over 7 days. Its EU and UK regional plan starts at £3.50, which is worth comparing if the UK is one stop on a longer trip.

Klook — for booking alongside tours

Klook’s UK eSIMad runs on O2, has a 4.3 rating from over 800 reviews, and refunds in full if you cancel before the eSIM connects. It is most useful if you are already booking attractions through Klook. Package prices depend on the dates and data you choose, so check them on the listing.

Holafly sells unlimited UK data priced by the day — £4 for one day, £42 for 16 days when we checked — with a 1GB monthly backup allowance after the plan ends. It is simple, but for a week or two it costs more than EE’s own eSIM.

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UK SIM cards with a phone number

A UK pay-as-you-go SIM gets you a +44 number, unlimited UK calls and texts, and far more data per pound. Every plan below runs for 30 days, and every network sells it as a physical SIM, most as an eSIM too.

O2 — the one to get if you are going on to Europe

O2’s Big Bundles are £10 for 8GB, £15 for 25GB, £20 for 40GB and £30 for 125GB, all with unlimited UK calls and texts and data rollover. The £15 and £20 bundles add 50 international minutes to over 42 countries, and the £30 bundle adds 250.

What makes O2 the pick for a longer trip is roaming. Every Big Bundle lets you use up to 25GB of your allowance in O2’s Europe zone at no extra cost. It supports 5G, 4G Calling and Wi-Fi Calling on pay-as-you-go, and eSIMs are available on every Big Bundle, online or in an O2 shop.

Three — the most data for the money

Three’s one-month data packs are £10 for 40GB, £15 for 100GB, £20 for 200GB and £35 for unlimited, speeds up to 25Mbps. Buy online with auto-renew and it gets better: £10 for 60GB, £13.50 for 120GB, £18 for 240GB, £31.50 unlimited, up to 50Mbps. There is also a three-month unlimited pack for £90.

Three’s Go Roam includes roaming in over 70 destinations: 6GB on the £10 pack, 12GB on £15, 18GB on £20 and 30GB on unlimited. Unlimited minutes and texts work in its Europe destinations.

Three catches. You cannot order a Three SIM on its own — you choose and pay for a data pack with it, though an eSIM arrives by email and works the same day. Your SIM must be used in the UK before it will roam. And once a pack’s data runs out you pay per megabyte until the pack ends, because Three only lets you hold one pack at a time; buy a Data Add-on instead.

Lebara — unlimited for £25, with EU and India roaming

Lebara runs on the Vodafone network, with no credit checks and no annual price rises. Its 30-day plans are £5 for 5GB, £10 for 30GB, £15 for 50GB, £20 for 100GB and £25 for unlimited data, with international minutes included on every plan — up to unlimited on the £20 and £30 plans. Roaming in the EU and India is included, up to 30GB.

giffgaff — cheap, on O2, but awkward for visitors

giffgaff runs on O2 and has some of the cheapest plans in the country: £10 for 15GB, £12 for 25GB, £15 for 30GB, £20 for 80GB on its one-month pay-as-you-go plans, with 5G included. Its monthly rolling plans give more data for the same money — £10 for 20GB — but renew automatically on a card.

The catch is getting one. giffgaff only delivers SIMs to UK addresses, so you either pick one up in a UK shop or use its eSIM. Only 5GB of your data works in the EU. And its adult content block can only be removed with a passport or a British driving licence.

EE — the best network, capped on pay-as-you-go

EE’s 30-day plans are £10 for 20GB (with 500 minutes), £15 for 75GB, £20 for 150GB, £30 for 200GB and £35 for unlimited, with 5G, data rollover and a free 1GB if you run out. Pay by recurring card for 10 per cent off.

Every one of those plans is capped at 25Mbps, which is why a visitor who wants EE’s network at full speed should buy the Travel eSIM instead. EE also charges for Europe: £2.50 for 24 hours or £10 for 7 days to use your allowance there.

Vodafone — fine, but not the best value

Vodafone’s Pay as you go Plus plans are £10 for 8GB, £15 for 25GB, £20 for 50GB, £30 for 150GB and £40 unlimited, with 5G and eSIM available. You need a smartphone and the My Vodafone app to manage the plan. A promotion to 8 December 2026 adds extra data for three months, but only if you keep auto-renew on for three consecutive card payments, which a visitor on a short trip will not.

Europe costs extra. Vodafone’s pay-as-you-go plans include roaming only in its Zone A — Ireland, the Isle of Man, Iceland and Norway — and Pay as you go Plus customers need to buy a roaming Extra to use their allowance anywhere else in Europe.

Lyca Mobile Travel eSIM — a UK number, bought after you land

Lyca Mobile, on EE, sells its pay-as-you-go plans as a Travel eSIM with a UK number: £5 for 5GB, £10 for 30GB, £25 for unlimited, each with 100 international minutes, and half price for the first month on the two larger plans. EU roaming is capped at 5GB, 12GB and 35GB respectively; the unlimited plan includes India too.

It has to be installed in the UK — Lyca says you cannot set it up before you arrive. Buy it on Lyca’s website after landing, or at Lyca’s self-service eSIM kiosks in Heathrow Terminal 2 and airside in Terminal 5.

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Going on to Europe with a UK SIM

Since Brexit, UK networks are free to charge for roaming in the EU, and several do. If your trip includes France, Spain or anywhere else in Europe, this decides which SIM to buy.

If you are travelling to several countries on an eSIM, a regional plan is simpler than a UK plan: Airalo’s EU and UK plan starts at £3.50, and Saily’s Europe plans from £3.99.

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Your home plan might already cover the UK

Check before you buy anything. Daily roaming passes are simple, keep your number, and cost far more than an eSIM for anything longer than a weekend.

Do the maths for your trip. A week on AT&T or Verizon is $84. A week of unlimited data on EE’s Travel eSIM is £15.

You can have both. Keep your home SIM switched on for calls and bank security texts, turn off its data roaming, and route your data through a travel eSIM — the setup is below.

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Before you buy: will your phone work?

It has to be unlocked

A phone locked to your home network will reject any other SIM or eSIM. On an iPhone, go to Settings → General → About and look for Carrier Lock: No SIM restrictions. On Android the setting varies by manufacturer; if you bought the phone on contract, ask your network to unlock it before you travel.

Check it supports eSIM

Dial *#06#. If an EID number appears, your phone supports eSIM. iPhones from the XS and XR onwards support it, except models sold in mainland China.

Calls need 4G Calling now

All four UK networks have switched off 3G — O2, the last, had most of its network off by early 2026. So an ordinary voice call on a UK SIM now needs a phone that supports 4G Calling (VoLTE) on that network.

EE, O2 and Vodafone can fall back to their 2G networks for calls if your phone does not. Three has no 2G network to fall back to. If you bought your phone abroad and the UK network does not recognise it for 4G Calling, data still works — so WhatsApp, FaceTime and other app calls are unaffected.

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Where to buy a physical SIM

Not at the airport. Arrivals-hall desks and vending machines charge a heavy markup for the same SIMs sold in town; our guide to buying a SIM at London airports goes terminal by terminal.

Supermarkets, newsagents and phone shops sell starter SIMs, usually free or 99p, and you add a plan once it is in your phone. UK pay-as-you-go SIMs are not registered, so you do not need ID to buy one.

The network’s own shop is worth the walk if you want someone to set it up, or if you need the adult content block lifted with your passport (see below).

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Paying and topping up with a card from abroad

Card payments are where visitors get stuck. Online payments and age checks on UK networks do not always accept cards issued abroad, and a declined card at the wrong moment leaves you without a plan.

The fix is a top-up voucher. Shops showing the green top-up sign sell vouchers for the UK networks, paid in cash or on any card at the till. Three says outright that a voucher needs no card details, and giffgaff lets you buy a plan with credit added that way.

Keep the number alive if you are coming back. Three disconnects a pay-as-you-go number that has had no chargeable use for 180 days — a call, a text, some data or a top-up resets the clock.

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The adult content block

Almost every UK SIM blocks 18-rated websites by default, and occasionally the filter catches sites that should not be blocked. Lifting it means proving your age, which is harder as a visitor:

• Three — on the Three app with a credit card (not a debit card, Apple Pay, Google Pay or prepaid card), or in any Three shop with photo ID.
• giffgaff — only with a passport or a full or provisional British driving licence. It can take up to 24 hours.
• O2 — blocks 18+ content by default and asks for proof of age to lift it.
• EE Travel eSIM — set to “Moderate”, which blocks 18-rated content, and cannot be changed.

If this matters to you, buy your SIM in a network’s own shop and ask them to lift the block there with your passport.

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Signal on the Tube

Mobile signal is arriving across the whole Underground. Transport for London said on 11 June 2026 that around 60 per cent of underground Tube stations now have 4G and 5G, with the whole network due by the end of 2026, and all four UK networks — EE, O2, Three and Vodafone — are part of it.

Right now there is signal in stations and tunnels on sections of the Central, Jubilee, Victoria, Northern, Piccadilly, Bakerloo, Circle and District lines, and on the whole Elizabeth line. The Central line is covered from Shepherd’s Bush to Bank, the Jubilee from Westminster to Canning Town, and the Victoria from Brixton to Green Park. TfL publishes a coverage map on its mobile and Wi-Fi page.

Station Wi-Fi is a different system. Every Tube station has Wi-Fi, but it connects through your UK network’s own service — EE WiFi-Auto, Wifi Extra for O2, Three_WIFI and VodafoneWiFi. A data-only travel eSIM does not give you access. There is no Wi-Fi in the tunnels.

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Setting up a travel eSIM alongside your home SIM

Keeping your home SIM active lets you receive calls and bank security texts on your usual number while all your data goes through the eSIM.

Before you leave, on Wi-Fi

1. Buy the eSIM and install it from the provider’s QR code or app.
2. Label the lines Home and Travel data in your phone’s settings.

When you land

1. Go to Settings → Mobile Data (Cellular on an iPhone).
2. Set Mobile Data to the Travel data line.
3. Turn off Allow Mobile Data Switching, so your phone never quietly falls back to your home line when the signal dips.
4. Keep Home as the default voice line if you need texts on your usual number.

Stop roaming charges

1. Turn Data Roaming off on the Home line.
2. Turn Data Roaming on on the Travel data line — most travel eSIMs connect by roaming onto a UK network, so they will not work without it.

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How much data will you use?

Maps, messaging and browsing use little. A 5GB to 10GB plan covers most visitors for a week if that is all you do.

Video is what burns through it. If you stream, upload video, make video calls home or tether a laptop, buy unlimited — and remember the 25Mbps cap on EE and Three pay-as-you-go plans if you are doing it on those.

Download offline maps before you fly. Google Maps will navigate without data if you have saved London over Wi-Fi, which is a useful backup in a building with no signal.

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Related guides

• Buying a SIM Card at London Airports: What It Costs
• Getting Around London: Complete Transport Overview
• London Public Transport Costs and Fares
• Oyster Card Guide for Visitors

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Prices, allowances and roaming terms checked on each provider’s own website on 14 September 2026. Network speed figures are from RootMetrics’ UK report for the first half of 2026; Tube coverage from Transport for London. Mobile plans change often — check the price when you buy.

Common questions

What is the best eSIM for visiting the UK?

For a trip of a week or two, EE's own Travel eSIM is the strongest deal: unlimited data at uncapped speed on the UK's fastest network, £15 for 7 days or £20 for 14 days, with no UK address needed. If you use less data, a fixed plan is cheaper — Nomad has 10GB for 30 days at about £13 and Saily has 10GB for £14.49. None of these gives you a UK phone number.

Can a tourist buy a UK SIM card?

Yes. Pay-as-you-go SIMs in the UK are not registered, and Lyca Mobile states plainly that you do not need ID to buy one. Starter SIMs are sold in supermarkets, newsagents and network shops, and most cost nothing or 99p before you add a plan. The catches are practical rather than legal: some networks only deliver SIMs to UK addresses, and some online payments and age checks do not accept cards issued abroad.

Which UK SIM is best if I am also travelling to Europe?

O2. Its pay-as-you-go Big Bundles let you use up to 25GB of your allowance in its Europe zone at no extra cost. Lebara, on the Vodafone network, includes EU and India roaming, and Three's data packs include between 6GB and 30GB of roaming depending on the pack. EE charges £2.50 a day to use your allowance in Europe, Vodafone pay-as-you-go needs a paid roaming Extra outside Ireland, the Isle of Man, Iceland and Norway, and giffgaff includes only 5GB.

Is it cheaper to use my US phone plan in the UK?

Rarely, for more than a couple of days. AT&T's International Day Pass and Verizon's TravelPass both cost $12 a day, so a week is $84 — against £15 for a week of unlimited data on EE's Travel eSIM. Many T-Mobile postpaid plans include data and texting in the UK at no extra cost, which is worth checking before you buy anything.

Do eSIMs work on the London Underground?

Where there is mobile signal, yes. Transport for London is rolling 4G and 5G out to every underground station and tunnel with all four UK networks, and said in June 2026 that around 60 per cent of underground stations were covered, with the whole network due by the end of 2026. The Wi-Fi in Tube stations is different: it connects through the UK networks' own Wi-Fi services, so a data-only travel eSIM does not unlock it.

Will my phone make calls on a UK SIM?

Probably, but check. All four UK networks have switched off 3G, so voice calls now need a phone that supports 4G Calling (VoLTE) on that network. EE, O2 and Vodafone can fall back to 2G for calls if it does not; Three has no 2G network to fall back to. Data works regardless, so WhatsApp and FaceTime calls are unaffected.