Is Three UK the right network for your 2026 SIM plan?

Which Three UK plan is best for you in 2026?

Entry SIM-only · Best value · No-commit rolling · Unlimited Data

For most users, 60 GB at GBP 8/month on a 12-month SIM-only contract is the value sweet spot — effectively GBP 0.13 per GB. Heavy users go to Unlimited Data at around GBP 16/month, which unlocks Three+ Discovery perks. Rolling 1-month buyers pick 60 GB at GBP 10. Anyone primarily chasing the Three network at the lowest price should look at SMARTY instead.

Source: three.co.uk SIM-only tariffs, verified May 2026

Three publishes a single in-life price for the contract term — the operator dropped CPI+3.9% mid-contract rises for new customers in April 2024 and now lists a fixed pound figure that kicks in from month 13 (typically GBP 1.50–2/month uplift). That is far cleaner than EE's CPI+3.9% model and matches the way SMARTY and iD Mobile present their pricing. The cheapest in-life cost of ownership over 12 months is therefore GBP 96 on the 60 GB plan, which beats EE's nearest equivalent by roughly GBP 4–5/month.

How is Three's network in the UK and London?

Fastest 5G · 99% UK population coverage · TfL Underground rollout

Three runs its own UK network as part of H3G (CK Hutchison). Opensignal's January 2026 report puts Three first for 5G download speed in London at 193.8 Mbps median, ahead of EE, Vodafone, and O2. Three covers 99% of the UK population on 4G and has rolled out 5G in 4,000+ locations. EE still leads on consistency, O2 on 5G availability, and Vodafone on reliability.

Three's 5G advantage comes from its 140 MHz of contiguous 3.4–3.8 GHz mid-band spectrum — the largest single C-band block of any UK MNO, acquired from the 2018 and 2021 Ofcom auctions plus the UK Broadband / Relish acquisition. That contiguous block means cleaner carrier aggregation and higher peak throughput. The trade-off shows up away from cities: rural Three 4G coverage trails EE by 4–6 percentage points on Ofcom's Connected Nations geographic measure, and 5G availability lags O2 nationwide.

Source: Opensignal "UK Mobile Network Experience" Jan 2026; Ofcom Connected Nations 2025

On the London Underground, Three is part of TfL's BAI Communications consortium rolling out 4G/5G across the tube network. The full Elizabeth line, the eastern and central Jubilee line, and roughly half of the Northern line are live as of May 2026. Coverage at platform level matches EE within a few decibels.

How much does Three cost compared to alternatives?

vs EE · vs Vodafone · vs O2 · vs SMARTY · vs iD Mobile

At the 60 GB tier, Three at GBP 8/month sits between SMARTY (GBP 7–8 for 100 GB) and EE (GBP 13+). Vodafone tracks Three closely on price but with a smaller 5G median speed. O2 is usually GBP 1–2 cheaper but loses on 5G download. Three is the cheapest direct-from-MNO option once you factor in no mid-contract CPI rise — that flat-pricing change is its biggest 2024–26 commercial shift.

Source: Operator pricing pages and Ofcom mobile market data, verified May 2026

What's special about Three's Unlimited Data plans?

Truly unlimited · No speed cap · Tether-friendly · Three+ Discovery perks

Three's Unlimited Data plan ships with no monthly cap, no fair-use throttling on most use cases, and full tethering rights — you can use it as a home broadband replacement under Three's 5G Hub or Mi-Fi packaging. Every Unlimited plan also activates Three+ Discovery, the operator's rewards programme: prize draws, partner discounts (Wuthering Bytes events, Hyde Park concerts, Snowbombing), and complimentary access to selected sporting and gig venues. EU roaming caps at 12 GB.

The differentiator vs EE Unlimited and Vodafone Unlimited Max is the absence of a tiered speed structure. EE charges extra for "Full Speed" Unlimited; Vodafone's Unlimited Lite caps at 2 Mbps. Three's Unlimited is one tier, top speed, GBP 16/month on a 24-month contract or GBP 20/month rolling. For heavy tetherers, cloud-gamers, and 4K streamers on the move, Three's Unlimited is the cheapest path to uncapped throughput on a UK MNO.

What are the pros and cons of Three?

Speed and value · Coverage and merger uncertainty

Three wins on raw 5G speed, unlimited-data pricing, and the absence of percentage-based mid-contract price rises. It loses on rural and indoor coverage compared to EE, on 5G availability compared to O2, and on long-term certainty given the active VodafoneThree integration. Best for urban users prioritising data throughput; weakest for rural users and frequent international travellers outside the EU.

How do you sign up for Three?

Six steps · eSIM in minutes · physical SIM next-day · PAC porting

Sign-up takes 5–15 minutes online at three.co.uk. A credit check is run for any contract longer than 1 month (most rolling plans skip it). UK address required for delivery. eSIM activates by QR code in the My3 app in minutes; physical SIMs ship next-day on standard tracked delivery.

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Should you pick Three or a Three MVNO (SMARTY/iD)?

Same network masts · Different perks · Different pricing

Both SMARTY and iD Mobile ride the exact same Three radio network — signal, speed, and indoor coverage are essentially identical. Pick a Three direct contract if you want Three+ Discovery perks, 5G priority traffic, and the cleanest customer-service path. Pick SMARTY or iD if you want the lowest sticker price, rolling-contract flexibility, and don't care about loyalty rewards.

Source: Operator pricing pages, verified May 2026

The practical rule: if your 60 GB monthly budget is tight, SMARTY's 100 GB at GBP 7/month is unbeatable. If you watch a lot of football and want match-day perks, Three direct on Unlimited is worth the GBP 1–2 premium. iD Mobile's 30 GB EU roaming cap and data rollover make it the most flexible mid-tier option on the Three network.

Will the Three-Vodafone merger change anything?

CMA-cleared Dec 2024 · VodafoneThree branding · 11-year investment commitment

The CMA cleared the Three–Vodafone merger in December 2024 with binding commitments: GBP 11 billion of network investment over 8–10 years, a 3-year price cap on existing Three and Vodafone customers' plans, and an MVNO-pricing commitment to protect SMARTY, iD Mobile, and Voxi. The combined entity now operates as VodafoneThree with roughly 27 million customers. Network integration is multi-year — existing Three SIMs continue to work normally on Three masts through at least 2027.

For someone signing a 12-month or 24-month contract today, the merger is effectively invisible. Three-branded plans, customer service, the My3 app, and Three+ Discovery rewards continue. The longer-term direction is a single VodafoneThree radio network (target: 99% 5G population coverage by 2034), and a single retail brand at some point — but neither change is scheduled before 2027 per CMA filings. The 3-year price-cap commitment means anyone who joins Three before merger-integration cutover gets price protection through to roughly late 2027.

How did we rank Three UK?

Sources · Scoring criteria · Affiliate disclosure

We scored Three on five criteria: network speed (Opensignal), coverage (Ofcom Connected Nations), tariff value (operator pricing pages), contract terms (mid-contract rise model + length), and EU/international roaming. Pricing was verified against three.co.uk on 14 May 2026. Network data comes from Opensignal's January 2026 UK Mobile Network Experience report and Ofcom Connected Nations 2025.

• Network speed (30%). Opensignal median 5G download speed, weighted London + national.
• Coverage and consistency (25%). Ofcom 4G/5G geographic population coverage, Opensignal consistency metric.
• Tariff value (20%). GBP per GB at the 60 GB tier, plus headline unlimited pricing.
• Contract terms (15%). Mid-contract rise model, contract length flexibility, early termination charges.
• Roaming and extras (10%). EU roaming cap, Three+ Discovery perks, eSIM support, VoLTE/VoWiFi.

SimCompare365 may earn a commission on confirmed sign-ups via the "Claim Deal" links on this page. Rankings are independent and not influenced by commercial relationships — see our affiliate disclosure and ethics policy. We re-verify pricing and network metrics quarterly.