Side-by-side independent data. No pricing — visit official sites for plan costs.
| Network | Type | 4G | 5G | EU Roaming | Best For | 2026 Key Fact |
|---|---|---|---|---|---|---|
| Three Mobile | MNO | 99% | 5G — 100 Mbps cap new | ✓ 163 countries | Unlimited; widest roaming | 27M; VodafoneThree merger |
| O2 | MNO | 99%+; 95% landmass | 5G / 5G+ SA / Satellite | ✓ 49 countries all plans | Coverage + Priority rewards | Europe's first satellite Feb 2026 |
| EE | MNO | 99%+ | 5G+ Standalone uncapped | Essentials Plus+ | UK's #1 — 11 years | 920/1,000 umlaut all-time record |
| Vodafone | MNO | 99% | 5G (VodafoneThree) | Varies by tier | Business + global roaming | 808/1,000 umlaut — UK 2nd |
| Tesco Mobile | MVNO | 99% (O2) | 5G via O2 | ✓ 48 destinations | Best service + Clubcard | 5th Uswitch Best Service |
| Giffgaff | MVNO | 99% (O2) | 5G via O2 | 5GB / 38 destinations | Budget; no annual rises | eSIM; Payback rewards |
| Sky Mobile | MVNO | 99% (O2) | 5G via O2 | Daily charge | Sky TV; data rollover 12mo | Piggybank now 12 months |
| SMARTY | MVNO | 99% (Three) | 5G via Three | ✓ 12GB / 42 dests. | Cheapest; data credit-back | Three-owned; 30-day only |
| iD Mobile | MVNO | 99% (Three) | 5G via Three | ✓ 30GB / 50 dests. | Generous worldwide roaming | eSIM; fixed prices |
| Your Priority | Best Option | Why |
|---|---|---|
| Best overall signal | EE | umlaut 920 (11 years); RootMetrics 93.2; Opensignal Reliability 915/1,000 |
| Best UK landmass coverage | O2 + Satellite | Opensignal Coverage winner; Starlink extends to 95% of UK landmass |
| Fastest 5G peak | Three (existing) / EE (new) | Three: 187 Mbps peak; capped 100 Mbps new plans. EE: uncapped + ARC tech |
| Widest international roaming | Three Complete | 163 Go Roam countries — USA, India, Japan, UAE, Canada, Kenya |
| Free EU roaming all plans | O2 | Only major MNO keeping EU free — 49 destinations, 25GB fair use |
| Best customer service | Tesco Mobile | 5× Uswitch Best Service 2022–2026; highest UKCSI mobile ranking |
| Price frozen for contract | Tesco Clubcard Price | Base price frozen — no annual rises — unique in UK mobile |
| Cheapest monthly MVNO | SMARTY or iD Mobile | Both on Three; SMARTY credits unused data; iD: 50 worldwide destinations |