Best SIM Plans in the UK 2026: 10 Carriers Compared

TL;DR: Top 3 Picks for the UK

Compare All 33 UK Plans on SimFinder →

Below, we break down the entire UK SIM market using real plan data from 10 carriers.

Table of Contents

• The UK Mobile Landscape
• Price Breakdown: All 33 Plans
• Best Plans by Use Case
• 5G and eSIM Availability
• Travel eSIMs for UK Visitors
• Frequently Asked Questions
• Key Takeaways

The UK mobile market is one of the most competitive in Europe. Four network operators — EE, Three, Vodafone, and O2 — power the infrastructure, while sub-brands and MVNOs resell that same connectivity at significantly lower prices.

SimFinder tracks 10 carriers and 33 plans in the UK. Prices range from just £5/month to £48/month. Every plan includes eSIM support, and 94% include 5G. The newest addition, iD Mobile, undercuts much of the market: 120GB for £12/month with data rollover, and the cheapest unlimited plan in the UK at £16/month — both on Three’s network.

This guide uses actual plan data, network quality measurements, and carrier ownership structures to help you find the right plan.

The UK Mobile Landscape: 4 Networks, 10 Carriers

Understanding the UK market starts with one fact: there are only four physical networks. Every carrier runs on one of these.

Quality data: OpenSignal Q1 2026

EE leads in every metric — fastest download speeds (120.4 Mbps), best coverage (94/100), and the highest overall score (88/100). It’s the only MNO with no sub-brands or MVNOs, which means the only way to access its network is through EE directly.

O2, Vodafone, and Three each host two additional carriers on their network. O2 has giffgaff and Tesco Mobile; Vodafone has VOXI and Lebara; Three has SMARTY and the newer iD Mobile. In every case, the sub-carriers dramatically undercut the parent network’s own pricing.

Vodafone sits in the middle with good speeds (100.5 Mbps) and coverage (91/100). Its sub-brand VOXI targets younger users with unlimited social media data, while Lebara focuses on international calling.

Three has the weakest scores (88/100 coverage, 78/100 overall) but competes aggressively on price. SMARTY offers some of the cheapest plans in the UK with a unique data rollover credit system, while iD Mobile is the newest entrant — a 12-month-contract carrier that undercuts on raw data and now offers the UK’s cheapest unlimited plan.

Carrier Structure

A clear pattern emerges: most sub-brands and MVNOs are contract-free. The exceptions are Tesco Mobile (24-month contracts on every plan) and iD Mobile (12-month contracts on most plans, though its 60GB rolling-monthly plan has no contract).

Price Breakdown: All 33 Plans

All 33 plans include eSIM support, unlimited calls (except EE Essentials 8GB which has 500 minutes), and tethering.

MNO Plans (EE, Three, O2, Vodafone)

Sub-brand & MVNO Plans

The pricing gap is significant. Budget carriers and MVNOs undercut MNOs by 30-60% for equivalent data. SMARTY offers 100GB for £10 with no contract — Three’s own 120GB Advanced plan costs £12 with a 12-month commitment. The newest entrant, iD Mobile, matches that 120GB at £12 but adds data rollover, and its Unlimited plan at £16/month is the cheapest unlimited SIM in the UK market (12-month contract). For raw capacity, O2’s 250GB at £15 is now the largest non-unlimited plan tracked, though it requires 12 months.

Note that giffgaff’s Goodybag tiers have shrunk considerably since our last update — the top Goodybag is now 30GB for £15, down from the 150GB it previously offered at the same price — so it’s no longer the standout value pick it once was.

EE stands apart as the premium option. Its Full Works plans are the most expensive in the market (£36-£48) but include bundled entertainment services and the UK’s fastest network.

Compare Plans Side by Side on SimFinder →

Best Plans by Use Case

Tightest Budget (Under £8/month)

Lebara 5GB — £5/month — The cheapest plan in the UK. Runs on Vodafone’s 5G network (100.5 Mbps, 91/100 coverage). Includes 100 international minutes to 42 countries and EU roaming at no extra cost. No contract. If you mainly use WiFi and want a basic plan for calls and light browsing, nothing is cheaper.

SMARTY 15GB — £6/month — Just £1 more for triple the data. Runs on Three’s network. The unique selling point: unused data gets credited back at £1 per GB. No annual price rises guaranteed. No contract.

At the £8 mark, two very different options compete: Three Essential 60GB offers a big data jump (up from 40GB at the same price) but requires a 12-month contract, while iD Mobile 30GB matches the price with less data but throws in rollover — also a 12-month contract.

Best Value for Most Users

SMARTY 100GB — £10/month — On Three’s network (90.2 Mbps, 88/100 coverage), 100GB with no contract and data rollover credits (£1 per unused GB) makes this the best per-pound deal that doesn’t require signing anything.

VOXI 100GB — £12/month — Same data as SMARTY at a higher price, but on Vodafone’s stronger network (100.5 Mbps, 91/100 coverage), with no contract and unlimited social media and music streaming that doesn’t count against your allowance. Strong choice if you use Spotify, Instagram, or TikTok heavily.

iD Mobile 120GB — £12/month — The newest carrier in our tracker wins on raw data: 120GB for £12 with rollover, though it requires a 12-month contract on Three’s network.

Heavy Data / Unlimited

iD Mobile Unlimited — £16/month — The cheapest unlimited data plan in the UK market, on Three’s network, with data rollover included as a bonus feature. Requires a 12-month contract.

Three Unlimited — £18/month — The cheapest unlimited plan from an MNO directly, though it also requires a 12-month contract. Three’s network scores lower than competitors (78/100 overall), but in urban areas the speeds are adequate.

VOXI Unlimited — £20/month — On Vodafone’s stronger network (82/100 overall) with no contract at all, plus unlimited social media, music, and video streaming. For contract-free unlimited data, this is the best option.

Premium / Best Network Quality

EE Full Works Unlimited — £48/month — For those who want the UK’s top network without watching a data allowance, EE’s Full Works Unlimited plan runs on the fastest infrastructure (120.4 Mbps, 94/100 coverage) and includes EU roaming, an inclusive Netflix subscription, and an Apple TV+ trial. EE also offers a lower-cost Full Works option around 100GB for £36 if you don’t need unlimited data. The 24-month contract and high price are the trade-offs for the best raw network experience.

Compare UK SIM Plans by Your Needs →

5G and eSIM Availability

eSIM

All 33 plans in the UK support eSIM — a 100% adoption rate. If you’re visiting the UK and your phone supports eSIM, you can set up a plan before arriving.

5G

31 of 33 plans (94%) include 5G. The only two exceptions:

Every plan from Three, O2, Vodafone, SMARTY, VOXI, giffgaff, Lebara, Tesco Mobile, and iD Mobile includes 5G. EE’s budget Essentials tier is the only holdout, deliberately restricting speeds to differentiate from its premium Full Works range.

Travel eSIMs for UK Visitors

If you’re visiting the UK short-term and only need data (no UK phone number), travel eSIM providers are an alternative. These are data-only plans that work in multiple countries.

Travel eSIMs are typically more expensive per GB than local UK plans, but they offer the convenience of multi-country coverage and instant activation. For stays longer than a few days, a local SIM from Lebara or giffgaff will usually be better value.

For a full comparison of travel eSIM options, use SimFinder’s travel search.

Frequently Asked Questions

Can I get a UK SIM without a long-term contract?

Yes. 15 of 33 plans in our database are rolling monthly with no contract. Carriers like giffgaff, VOXI, SMARTY, and Lebara specialise in contract-free plans, and EE’s Essentials tier is also month-to-month. Even carriers that offer 12- or 24-month terms charge no cancellation fees on any plan we track.

Which UK network has the best coverage?

EE leads with a coverage score of 94/100, followed by O2 at 92/100, Vodafone at 91/100, and Three at 88/100. If you travel to rural areas frequently, EE or O2 are the safest choices. Sub-brands and MVNOs use the same towers as their parent network.

What is the cheapest SIM plan in the UK?

Lebara 5GB at just £5/month. It includes unlimited calls, 5G, eSIM, and 100 international minutes to 42 countries. For more data on a budget, SMARTY 15GB costs £6/month with data rollover.

Is 5G available on all UK plans?

Nearly. 31 of 33 plans (94%) include 5G. The only exceptions are two EE Essentials plans (8GB and 25GB), which are speed-capped at 25 Mbps and limited to 4G. Every other carrier offers 5G on all plans.

Do all UK SIM plans support eSIM?

Yes. All 33 plans tracked by SimFinder support eSIM. This means you can activate a UK plan remotely before arriving in the country, provided your phone supports eSIM.

What is the best SIM for visitors or tourists to the UK?

Lebara 30GB at £8/month is a strong choice — it includes 100 international minutes to 42 countries, EU roaming, 5G, and eSIM. For a shorter stay, travel eSIM providers like Airalo or Holafly also cover the UK if you only need data.

Which UK carrier offers the best value for heavy data users?

O2 250GB at £15/month offers the most data per pound of any non-unlimited plan (16.7GB per £), though it requires a 12-month contract. For a contract-free option, SMARTY 100GB at £10/month matches the per-pound value of Three Advanced 120GB and iD Mobile 120GB (both £12) without signing anything. For truly unlimited data, iD Mobile Unlimited at £16/month is now the cheapest unlimited plan in the UK (12-month contract) — VOXI Unlimited at £20/month is the cheapest contract-free option.

Key Takeaways

The UK SIM market in 2026:

• 10 carriers, 33 plans — all with eSIM support and unlimited calls (except EE Essentials 8GB)
• Four networks: EE (fastest, best coverage at 94/100), O2 (92/100), Vodafone (91/100), Three (88/100)
• Budget carriers save 30-60%: SMARTY 100GB costs £10 with no contract vs O2’s 80GB at £10 with a 12-month contract
• 5G is near-universal — 94% of plans include it; only EE’s Essentials tier restricts access
• No-contract plans dominate the budget tier: giffgaff, VOXI, SMARTY, and Lebara are all rolling monthly
• Price range: £5/month (Lebara 5GB) to £48/month (EE Full Works Unlimited)
• New entrant: iD Mobile joined the market on Three’s network with data rollover and the UK’s cheapest unlimited plan at £16/month
• Special features: SMARTY and iD Mobile offer data rollover, VOXI includes unlimited social media data, Lebara includes international minutes

For most users, the best approach is: pick the network coverage you need (EE for best coverage, O2 for strong coverage plus cheap MVNOs, or Three for the cheapest carriers like SMARTY and iD Mobile), then find the cheapest carrier on that network.

Find Your Best UK SIM Plan →

Plan data is current as of July 2026. Prices and inclusions may change. Check carrier websites for the latest information.

Compare all plans side by side using SimFinder’s comparison tool.