Three vs o2 eSim Comparison
Three vs O2 eSIM comparison in 2026 shows Three leading with faster 5G speeds up to 276Mbps and unlimited data from £12/mo, ideal for streaming/gaming, while O2 excels in 4G coverage (99%) and EU roaming up to 25GB on plans from £6.99/mo for 12GB.
Both support instant QR eSIM activation on iPhone 14+/Galaxy S23, but Three offers better WiFi calling on more devices; O2 adds Priority perks like free Virgin Media trials. Choose Three for urban speed, O2 for rural reliability and roaming.
| Feature | Three | O2 |
|---|---|---|
| 5G Speed | 276Mbps | 85Mbps |
| Data Example | Unlimited £20/mo | 40GB £8/mo |
| Coverage | 588+ 5G sites | 3200+ 5G locations |
| EU Roaming | 12GB limit | 25GB o2.co.uk |
Which Delivers Faster Data Speeds?
Three tops charts at 208-276Mbps 5G downloads via 140MHz spectrum, perfect for UHD streaming in London/Manchester. O2 lags at 80-85Mbps but sufficient for HD video. Both uncapped; Three edges 4G at 38Mbps vs O2’s 23Mbps.
- Urban: Three 5G dominant.
- Indoor: O2 WiFi hotspots free at 15K+ sites.
- 2026 tests: Three 3x faster 5G, O2 consistent 4G.
How Do Coverage Maps Compare UK-Wide?
O2 boasts superior 4G/2G/3G for calls/texts across rural Scotland/Wales at 99%, with 3200+ 5G spots. Three focuses 5G in cities (588+ sites), weaker voice signal sans 3G. eSIM profile swaps seamless on both.
| Area | Three Strength | O2 Strength |
|---|---|---|
| Urban 5G | 208Mbps | 80Mbps |
| Rural 4G | Good | 99% coverage |
| Voice/SMS | WiFi calling | Native 2G/3G |
What Roaming and Perks Differentiate?
O2 includes 25GB EU roaming no extra cost, vs Three’s 12GB cap; Three shines outside EU with 160+ zones on premium plans. O2 Priority: early tickets/streaming trials; Three: Paramount+ subscription, phone warranty.
- eSIM support: Three broader Android compatibility.
- WiFi calling: Three more flexible, O2 visual voicemail.
- Contracts: Both 12/24-mo, PAYG data rollover on O2.
When to Pick Three vs O2 eSIM?
Opt for Three eSIM on 5G-heavy urban contracts needing speed/unlimited data; O2 eSIM for balanced coverage, roaming, and perks on lighter plans. Activation via app/QR in 2 mins; tethering uncapped both. three.co.uk

Tasnima Tabassum Ema is the Founder and Lead Data Analyst at eSIM Expart. Driven by her own costly roaming nightmares, she built the site to save fellow travelers money. She specializes in rigorous, real-world testing and calculating the true cost per Gigabyte ($/GB) to ensure you always get the cheapest, most reliable connection.