Networks on O2: virtual operators using their signal ranked

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We walk you through options to get a phone deal on the O2 network with one of the smaller providers that piggyback on O2. Last updated: 17th January 2022.
In our guide
Lower costs than O2 with different benefits

✔ Use O2’s masts with other providersSkip to the networks
We consistently give O2 a very good rating in our full network review, based on the quality of their mobile network coverage, particularly for calls and texts but also data. But O2 are one of the pricier providers.
If you want a phone contract, don’t write off O2 immediately. You can get good deals by signing up via other retailers that sell phones on O2 (compare them here). O2’s SIMs with big data are also pretty competitive:
But short of that, it is a good idea to think about virtual mobile networks that piggyback on O2, as they mostly offer better prices and some unique benefits you won’t get on O2 themselves.
Below, we go through all the networks that use O2 and show you how close they come to being on O2 directly in terms of network features and also how good their pricing and unique benefits are.
Skip to: Networks on O2 | SIM only plans | Phone contracts
Providers using O2
Sky Mobile offer closest network experience to O2
What we like: Identical 5G/4G/3G/2G coverage
WiFi calling and 4G calling
Flexible, well-priced phone contracts
Excellent added benefits
What we don't like: Customer service hard to get hold of
Out of all providers on O2, only Sky Mobile have the full set of network features to match O2. On Sky, you get 5G data with every plan and WiFi calling and 4G calling features (read our O2 vs Sky guide for the full story).
From testing Sky Mobile for our review, we weren’t able to find any coverage differences. And despite some Sky customer forum discussion, we’ve never been able to find any speed differences between the two either.
And that’s good news, because Sky Mobile’s phone contracts mostly beat O2 on price. And if you want a small or mid-range SIM only, Sky are normally cheaper than O2 (large data is worth comparing still):
Sky also offer loads of unique added benefits you don’t get on O2 too. You’ll keep unused data for three years and can share it or trade it for discounts. And watching Sky TV apps won’t use up your data.
Overall, Sky aren’t just our favourite virtual provider on O2, they’re one of our overall best-rated networks. And you don’t need to be a broadband or TV customer with Sky to benefit.
Useful link: Read our full Sky Mobile network review
Tesco Mobile offer a similar experience to O2
What we like: Identical coverage to O2
Nice benefits for families and Tesco shoppers
Good phone contracts and SIM prices
What we don't like: No WiFi calling or 4G calling
No hotspot provision
Another decent choice on O2 is Tesco Mobile. They were long actually part-owned by O2 and use their network. The coverage is the same and you’ll even get 5G data as standard too (read our full Tesco review).
The main thing lacking on Tesco Mobile vs O2 is WiFi calling and 4G calling. These kick in when conventional mobile signal is weak (like indoors) and let your phone use WiFi to make/take calls instead.
As long as you know that, you can often get slightly better prices on Tesco Mobile’s phone contracts like-for-like. And Tesco’s SIM only plans are almost always lower cost, particular mid and low data amounts:
Tesco don’t have as interesting benefits as Sky but there are some nice things like discounts for Clubcard holders, Family Perks when you have multiple deals with them and Tesco have held onto EU roaming.
They’ve also got a great customer service record and there’s the convenience of being able to drop in and see their staff whenever you’re doing your shopping at Tesco too. A decent choice all round we think.
Useful link: Our full network review of Tesco Mobile
giffgaff now have most of the features O2 do
What we like: Coverage the same as O2
No commitment on SIM only
Flexible, well-priced phone deals
What we don't like: No WiFi calling or 4G calling
Online-only customer service
You’ll now get 5G on all giffgaff plans, meaning the basic 5G/4G/3G/2G is the same as on O2. The main thing you’ll miss network-wise on giffgaff is WiFi calling and 4G calling. You can even use O2 Extra WiFi hotspots.
There are suspicions among giffgaff customers that they’re getting slower data speeds than O2 directly. But we’ve never been able to verify that in our testing for our giffgaff network review (we found same speeds).
We like the flexibility you get with giffgaff’s SIM only plans. There’s no contract, you’re free to leave whenever and change plans. Although price-wise, they’re beatable, though cheaper than O2 for 1-month plans:
It pays to compare giffgaff’s phone contracts too. Although these are very flexible and based on finance for the phone, the prices aren’t a slam dunk in terms of beating O2 directly or via retailers selling phones on O2.
There are some nice benefits to being on giffgaff. They’re built on the idea of a community of members, which some will like. But it’s online-only customer service - worth knowing if you’re not a confident user.
Useful link: Read our full giffgaff review
Lycamobile use O2’s network and even have 5G data
What we like: Same coverage
No credit check SIMs
Great for international calls
What we don't like: No WiFi calling or VoLTE
If you didn’t know, international calls specialists Lycamobile are also on the O2 network. Whether or not you’re interested in calling abroad, you can still get the same coverage with them as O2, even on 5G.
Lycamobile are generally very low-frills. But you do get a nice flexible plan you can change each month, not renew or leave altogether. And if you have family or friends abroad, they’ve got good international rates.
Like most of the providers that use O2 (apart from Sky), you won’t get WiFi calling or 4G calling on Lycamobile, so if signal does struggle to get indoors where you use your phone, it’s too bad.
But overall, you can get some really good value for money on Lyca, so definitely worth considering if you can do without those extra features
Useful link: Learn more about Lycamobile
SIM only plans on O2-based networks
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