O2 UK SIM & eSIM Plans Reviewed (2026)
London 5G availability
77.8%
Opensignal Jan 2026, #1
Cheapest plan
GBP 7
10 GB / 12 mo
EU roaming
25 GB
Europe Zone, most plans
Social tariff
GBP 10
Essential 10 GB
Which O2 plan is best for me?
For most users, O2 100 GB at GBP 12 is the value sweet spot — it includes 25 GB EU roaming and Priority perks. Heavy users go to Unlimited at GBP 23. Households on benefits should look at O2 Essential at GBP 10/month for 10 GB with no annual price rise.
| Plan | Contract | Price | Data | EU roaming | Notes | Action | Action |
|---|---|---|---|---|---|---|---|
| 10 GB SIM-only | 12 mo | GBP 7/mo | 10 GB | 25 GB | Priority included | Claim Deal | |
| 50 GB SIM-only | 12 mo | GBP 9/mo | 50 GB | 25 GB | Priority included | Claim Deal | |
| 100 GB SIM-only | 12 mo | GBP 12/mo | 100 GB | 25 GB | Priority included | Claim Deal | |
| Unlimited | 24 mo | GBP 23/mo | Unlimited | 25 GB | Plus tier perks | Claim Deal | |
| Unlimited 1 month | 1 mo | GBP 38/mo | Unlimited | 25 GB | No commitment | Claim Deal | |
| Essential (social) | 1 mo | GBP 10/mo | 10 GB | UK only | No price rise; eligibility check | Claim Deal |
How is O2's network in the UK and London?
O2 leads 5G availability in London at 77.8% in Opensignal's January 2026 report — your phone is on 5G a higher share of the time than on any other UK network. Three leads raw 5G download speed; EE leads consistency; Vodafone leads reliability. O2 customers also get access to O2 Wi-Fi hotspots and O2 Satellite outside cellular coverage on compatible devices.
What is O2 Priority and is it worth it?
Priority is O2's loyalty app, available at no extra cost to every customer. It bundles:
- · Early ticket access for shows at The O2 arena and other UK venues
- · Weekly free perks like coffee at Greggs or Cafe Nero on rotation
- · Restaurant offers at chains and independent venues
- · Prize draws for premium experiences
For London users, the early-access ticketing alone often justifies picking O2 over a cheaper MVNO.
What are the pros and cons of O2?
Pros
- Best 5G availability in London (77.8%)
- O2 Priority perks at no extra cost
- Up to 25 GB EU roaming on most plans
- O2 Wi-Fi hotspots and O2 Satellite
- Strong shop network including airports
- Essential social tariff at GBP 10
- eSIM, VoLTE, VoWiFi all supported
Cons
- Three is faster on raw 5G in London
- EE leads on consistency
- O2-network MVNOs (giffgaff, Tesco, Sky) are cheaper
- Annual price rises on most non-social plans
- 24-month commitment for the cheapest unlimited price
Frequently asked questions about O2
Is O2 a good network in London?
Yes for 5G availability. O2 leads time-on-5G in London at 77.8% in Opensignal's January 2026 report. Three leads raw speed; EE leads consistency; Vodafone leads reliability. Pick O2 if you want 5G to be the default network state when you are out and about.
How much does O2 cost?
O2 SIM-only starts at GBP 7/month for 10 GB on a 12-month contract. 50 GB is GBP 9, 100 GB is GBP 12, and Unlimited is GBP 23 on 24 months. The O2 Essential social tariff is GBP 10/month for 10 GB.
What is O2 Priority?
Priority is O2's loyalty perks app. It includes early ticket access for The O2 arena, weekly free coffee at Greggs or Cafe Nero on rotation, restaurant offers, and prize draws. Available to every O2 customer at no extra cost.
Does O2 include EU roaming?
Most O2 SIM-only plans include the Europe Zone with up to 25 GB of EU roaming. Plus and Ultimate plans add wider roaming zones.
What is the O2 Essential Plan?
O2 Essential is a social tariff for households on Universal Credit or other qualifying benefits. It costs GBP 10/month for 10 GB of data with unlimited UK calls and texts on a 1-month contract. No annual price rise. Apply via O2's social-tariff page with proof of benefits.