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 43 plans in the UK. Prices range from just £5/month to £35/month. Every plan includes eSIM support, and all of them 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 43 plans include eSIM support, unlimited calls and texts, 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 has replaced its old Essentials/Full Works split with a capacity-based lineup on 24-month terms. Its unlimited tiers (£26 Essentials Plus Max, £33 All Rounder for iPhone) still carry the UK’s fastest network, but the entry plans now start at £15 for 20GB.

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, three options compete: SMARTY 50GB and Lebara 30GB are both contract-free, while iD Mobile 30GB matches the price and throws in data rollover on 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 Value (24-month) — £22/month — The cheapest unlimited plan from an MNO directly, on a 24-month term that rises to £24.30 in April 2027 and £26.60 in April 2028. Three’s network scores lower than competitors (78/100 overall), but in urban areas the speeds are adequate.

Three Unlimited Value (1-month) — £25/month — The cheapest contract-free unlimited plan in the UK, billed monthly with no commitment. VOXI Unlimited is also contract-free on Vodafone’s network with unlimited social media, music, and video streaming, but now costs £35/month.

Premium / Best Network Quality

EE Unlimited Essentials Plus Max — £26/month — For those who want the UK’s top network without watching a data allowance, this plan runs on the fastest infrastructure (120.4 Mbps, 94/100 coverage) and includes 50GB of EU roaming data. EE also sells a 100GB plan at £21 if you don’t need unlimited data, and an All Rounder for iPhone tier at £33. All are 24-month terms that rise each 31 March (the £26 plan goes to £28.50 in 2027 and £31 in 2028).

Compare UK SIM Plans by Your Needs →

5G and eSIM Availability

eSIM

All 43 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

All 43 plans include 5G — a 100% adoption rate. EE’s 4G-only “Essentials” tier (speed-capped at 25 Mbps) has been withdrawn, which removed the last non-5G plans from our UK dataset.

Every carrier we track — EE, Three, O2, Vodafone, SMARTY, VOXI, giffgaff, Lebara, Tesco Mobile, and iD Mobile — now includes 5G on every plan.

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.

Prices below are SimFinder’s tracked rates for UK-only data plans as of August 2026. Links marked with ↗ are affiliate links — we may earn a commission at no extra cost to you.

Cheapest for a week: Airalo at $4.00. Cheapest for a month: Ubigi at $11.00 for 10 GB — less than a third of Airalo’s 30-day rate, and the only provider here that beats Lebara’s £5 plan on price without needing a UK address.

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. 16 of 43 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?

Yes. All 43 plans we track include 5G. EE’s old 4G-only Essentials tier has been retired, so every plan in our UK dataset is now 5G-capable.

Do all UK SIM plans support eSIM?

Yes. All 43 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 is the best per-pound value without signing anything. For truly unlimited data, iD Mobile Unlimited at £16/month is the cheapest unlimited plan in the UK (12-month contract) — Three Unlimited Value at £25/month is the cheapest contract-free option.

Key Takeaways

The UK SIM market in 2026:

• 10 carriers, 43 plans — all with eSIM support and unlimited calls and texts
• 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 universal — every plan we track includes it
• No-contract plans dominate the budget tier: giffgaff, VOXI, SMARTY, and Lebara are all rolling monthly
• Price range: £5/month (Lebara 5GB) to £35/month (VOXI 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.