Looking for the best O2 SIM only deals in 2026? Whether you want a cheap monthly plan, unlimited data, EU roaming, or flexible 30-day contracts, O2 offers some of the most competitive SIM-only packages in the UK.
In this guide, we’ll compare:
✔ Latest O2 SIM only prices
✔ Best plans for data, budget & unlimited usage
✔ 30-day vs 12-month vs 24-month contracts
✔ O2 extras & roaming benefits
✔ Which deal is best for YOU
🔎 Why Choose an O2 SIM Only Deal?
O2 SIM-only plans are popular because they offer:
- No handset cost
- Lower monthly bills
- Flexible contracts
- Free EU roaming
- Access to O2 Priority rewards
You also get 5G, unlimited UK minutes & texts on most plans.
💰 Cheapest O2 SIM Only Deals (2026)
O2 offers plans for every budget.
🔹 Entry-Level Plan
- From £7/month
- 1GB data
- Unlimited minutes & texts
- 30-day flexibility available
🔹 Best Budget Data Plan
- Around £8/month
- 30GB–40GB data
- 12-month contract options
👉 Perfect for light users & students.
📊 Popular O2 SIM Only Plans & Prices
| Monthly Price | Data | Contract | Best For |
|---|---|---|---|
| £10 – £15 | 20GB – 40GB | 12 months | Everyday users |
| £16 | Up to 250GB | 12–24 months | Heavy streaming |
| £24.99 | Unlimited data | 24 months | Power users |
O2’s 250GB plan for ~£16/month is one of the best value high-data deals in the UK.
The Unlimited Plus plan (£24.99) includes roaming in 75 destinations and streaming perks.
📅 30-Day vs 12-Month vs 24-Month SIM Only
30-Day Rolling SIM
✔ Maximum flexibility
✔ Switch anytime
❌ Highest monthly price
12-Month Plan
✔ Lower monthly cost
✔ Good balance
24-Month Plan
✔ Cheapest per month
✔ Best for long-term users
Unlimited data plans are available on all durations, but longer contracts are cheaper.
🌍 O2 Roaming – A Major Advantage
O2 is one of the few UK networks that still offers:
✅ Free EU roaming (up to 25GB fair-use)
✅ Use your UK allowance abroad at no extra cost
With higher plans you also get:
🌎 Roaming in 75 worldwide destinations
including USA, Australia & more.
👉 That makes O2 one of the best SIMs for travellers.
🎁 O2 Extras – Free Streaming & More
With selected SIM-only plans you can choose:
- Disney+
- Amazon Prime
- Audible
- Amazon Music
Free for 3–6 months or for the full contract depending on the tariff.
⭐ O2 Priority – The Hidden Money Saver
O2 customers get:
- Early access to concert tickets
- Free coffees & food deals
- Exclusive discounts
These perks alone can save hundreds of pounds per year.
📶 Data Rollover & International Minutes
Some O2 bundles also include:
- Data rollover
- Up to 250 international minutes
- EU roaming included
👨💻 Best O2 SIM Only Deal for Different Users
🧑🎓 Best for Students & Budget Users
£8–£10 plan
✔ 20GB–40GB data
✔ Low monthly cost
📱 Best for Average Users
£10–£15 plan
✔ Enough data for daily use
✔ Great value
🎬 Best for Streamers & Gamers
£16–£25 plan
✔ 100GB–Unlimited data
✔ 5G ready
✈️ Best for Travellers
Unlimited Plus plan
✔ 75 country roaming
✔ Entertainment included
⚖️ O2 SIM Only Pros & Cons
✅ Pros
✔ Free EU roaming
✔ Flexible plans
✔ O2 Priority rewards
✔ 5G included
✔ Streaming extras
❌ Cons
❌ Mid-contract price rises (some plans)
❌ Slightly slower speeds than EE
(From April 2026 some contracts may rise by about £2.50/month, so compare new deals before renewing.)
🏆 Best O2 SIM Only Deals – Our Top Picks (2026)
🥇 Best Overall Value
👉 40GB for ~£10–£12/month
🥈 Best High-Data Deal
👉 250GB for ~£16/month
🥉 Best Unlimited Plan
👉 Unlimited data for £24.99/month
📌 Is O2 SIM Only Worth It in 2026?
YES — especially if you want:
✔ Free EU roaming
✔ Entertainment perks
✔ Flexible plans
✔ Strong UK coverage
It’s one of the best value SIM-only networks for travellers, students, and heavy data users.
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❓ FAQ (For Featured Snippets)
What is the cheapest O2 SIM only deal?
Plans start from around £7/month with unlimited minutes and texts.
Does O2 still offer free EU roaming?
Yes, you can use up to 25GB of your data in Europe at no extra cost.
Is O2 unlimited data worth it?
Yes, especially for streaming, gaming, and frequent travellers.