Best SIM Plans in the UK 2026: 9 Carriers Compared

TL;DR: Top 3 Picks for the UK

Compare All 29 UK Plans on SimFinder →

Below, we break down the entire UK SIM market using real plan data from 9 carriers.

Table of Contents

• The UK Mobile Landscape
• Price Breakdown: All 29 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 9 carriers and 29 plans in the UK. Prices range from just £5/month to £48/month. Every plan includes eSIM support, and 93% include 5G. The variation in value is dramatic — you can get 150GB on O2’s network for £15/month from giffgaff, while O2 itself charges £15 for 250GB but requires a 12-month contract.

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, 9 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 has the most carrier ecosystem: giffgaff and Tesco Mobile both run on its network. O2’s coverage score of 92/100 is strong, and its sub-carriers dramatically undercut O2’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. Its sub-brand SMARTY offers some of the cheapest plans in the UK with a unique data rollover credit system.

Carrier Structure

A clear pattern emerges: all sub-brands and MVNOs except Tesco Mobile are contract-free. If flexibility matters, budget carriers are the obvious choice.

Price Breakdown: All 29 Plans

All 29 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 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. giffgaff’s 150GB for £15 is contract-free, while O2’s 250GB at £15 requires 12 months.

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.

Best Value for Most Users

giffgaff Goodybag 75GB — £12/month — On O2’s network (95.1 Mbps, 92/100 coverage), 75GB is more than enough for most users. No contract, 5G included, eSIM supported. giffgaff’s “Goodybag” model means you buy a new one each month with no commitment. At £12 for 75GB, the per-gigabyte cost is just £0.16.

VOXI 100GB — £12/month — Same price as giffgaff’s 75GB but with 100GB on Vodafone’s network. VOXI also includes unlimited social media and music streaming data that doesn’t count against your allowance. Strong choice if you use Spotify, Instagram, or TikTok heavily.

Heavy Data / Unlimited

Three Unlimited — £18/month — The cheapest unlimited plan from an MNO, though it 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 — Only £2 more than Three, but with no contract and on Vodafone’s stronger network (82/100 overall). Also includes unlimited social media, music, and video streaming. For contract-free unlimited data, this is the best option.

Premium / Best Network Quality

EE Full Works 100GB — £36/month — For those who want the UK’s top network, EE’s Full Works plans run on the fastest infrastructure (120.4 Mbps, 94/100 coverage). Includes EU roaming, BT Sport trial, and Apple Music trial. 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 29 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

27 of 29 plans (93%) include 5G. The only two exceptions:

Every plan from Three, O2, Vodafone, SMARTY, VOXI, giffgaff, Lebara, and Tesco 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. 14 of 29 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. 27 of 29 plans (93%) 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 29 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?

giffgaff Goodybag 150GB at £15/month offers the most data per pound among non-unlimited plans. For truly unlimited data without a contract, VOXI Unlimited at £20/month is the cheapest option. Three Unlimited at £18/month is cheaper but requires a 12-month contract.

Key Takeaways

The UK SIM market in 2026:

• 9 carriers, 29 plans — all with eSIM support and unlimited calls
• Four networks: EE (fastest, best coverage at 94/100), O2 (92/100), Vodafone (91/100), Three (88/100)
• Budget carriers save 30-60%: giffgaff 150GB costs £15 vs O2’s 100GB at £12 (with a 12-month contract)
• 5G is near-universal — 93% 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)
• Special features: SMARTY offers data rollover credits, 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 + cheap MVNOs), then find the cheapest carrier on that network.

Find Your Best UK SIM Plan →

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

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