O2 SIM only deals: 12GB for £6.99, 50GB for £8.50
The retailers featured on this page may compensate us when our readers follow links to their websites and make a purchase. More
We've looked at SIM only on all UK networks to help you find out which of O2's plans work out best, for every data requirement. Last updated: 10th October 2025.
O2's best SIM only deals
The best value SIM only deal on O2 this month
just
£6.99
a month
✔ Unlimited mins and 12GB data See full deal
at o2.co.uk
(opens in new window)
From all the options O2 have got available this October on SIM only, we think this discounted £6.99 12‑month deal is their best. For your £6.99 a month, you get 12GB data alongside unlimited minutes and texts:
You can get a lower-priced SIM with 12GB data or more elsewhere if you don't need it to use the O2 network. But if you do need that, it is the cheapest deal available. See lower-priced networks' deals here:
We also like their £8.50 for 50GB plan
just
£8.50
a month
✔ Unlimited mins and 50GB data See full deal
at o2.co.uk
(opens in new window)
To get a bigger data allowance, we also think this discounted £8.50 O2 SIM is one of their best options. It comes with 50GB data, unlimited minutes and texts on a 12‑month deal:
It's not actually the cheapest SIM only deal on the market at the moment with 50GB data or more but it is the lowest-priced plan on any provider using the O2 network. Here are other networks you can beat it on:
Their 80GB for £10 SIM is another good option
just
£10
a month
✔ Unlimited mins and 80GB data See full deal
at o2.co.uk
(opens in new window)
To get an even bigger chunk of data, O2's discounted £10 SIM below is another of their best deals this month. For £10 a month, it offers 80GB data, unlimited minutes and texts on a 12‑month plan:
You can beat it for price if you don't need your SIM to be with a provider using the O2 network. But if that's a must, then it is the lowest-cost SIM with 80GB data or more. See the networks with cheaper plans here:
O2's 250GB for £15 plan is a good option too
just
£15
a month
✔ Unlimited mins and 250GB data See full deal
at o2.co.uk
(opens in new window)
If you need even more data, the next best SIM only plan on O2 in our opinion is their discounted 12‑month one below. For £15 a month, you get 250GB data, plus unlimited minutes and texts:
While this is a good enough deal to make it into the best of O2's SIMs, you can beat it for price (even if you definitely want a provider that uses the O2 network). Here's which other networks can beat it:
Compare all SIM only plans
Compare deals from all networks
How O2's deals compare with other networks
Networks
Providers:
Plan
Data: (0MB+)
Minutes: (0+)
Thanks, we'll send that out now. Please check your inbox for our email.More about O2's SIM only plans
O2’s SIM only prices and benefits compared
In our full review of the O2 network we said we liked their brilliant call signal (3G/2G) coverage, their good 5G coverage and their great WiFi hotspot scheme. We also like their WiFi calling and 4G calling.
You have the choice of 1-month, 12-month and 24-month contracts. Their 24-month contracts are usually much cheaper per month, but it’s best to check their current deals for the best possible offer.
O2’s deals tend to be some of the most expensive of all networks, but they’re a bit more competitive on big data deals. There are some smaller providers on O2’s network who offer better value SIM only deals.
They’re also the only main UK network to still offer inclusive EU roaming on all plans. And you can get extras on premium plans, such as subscriptions to entertainment services and worldwide roaming data passes.
Useful link: Read our full O2 review
Other things to know about O2’s SIM only deals
You’ll get your O2 SIM card between 1-4 working days after ordering (depends on your location). And there are premium delivery options too. You’ll receive each size of SIM for any phone. Or you can take an eSIM.
When your SIM arrives, you have 14 days to return it and get a full refund if you’re not satisfied. This will also cancel your contract. Here’s how you do that.
To prevent customers racking up huge bills they can’t pay, O2 make you pass a credit check to join them. If you have a poor or no credit history you can still join O2 on a PAYG monthly bundle instead.
And if you’re switching to O2 from another network you can keep your number by requesting a PAC from your old provider and giving it to O2 at any point. Here’s how you do that.
Useful link: Compare all O2 SIMs