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We look at how 4G/5G network coverage, speeds and other benefits compare between joining O2 directly or Tesco Mobile. Last updated: 15th February 2022
We tested both networks to find out
Tesco are a separate operator from O2, but still piggyback off them for their signal. That means you get signal in the same areas on Tesco Mobile as you would on O2.
You also get the same signal strength. O2 cover the joint-largest percentage of the UK’s landmass for call signal (3G/2G) and 98% of the places where people actually live. You’ll rarely find yourself in a total blackspot.
O2’s 4G data coverage in rural areas isn’t as good as some networks. But their 5G coverage is pretty good. You get 5G in these 190+ locations with decent street-by-street coverage in those locations.
There’s not really much else to go into. The best thing to do is to use their coverage checkers to see how coverage is in your local area. Check at home and anywhere else you’re expecting to have to use your phone.
Useful link: Which network has the best indoor signal?
Check signal everywhere you'll use your phone, not just at home
"Since signal coverage is the same on both networks there’s nothing to separate them on here. Your choice between them should be based on the extra features and benefits they offer instead."
We’ve tested a Tesco and O2 SIM in the same phone against each other and found no difference in speeds between the two networks, so we’re confident in using results from independent network testers Opensignal to apply to both.
They measure average 4G speeds around 17.1 Mbps. That’s unfortunately the slowest of all mobile networks, and if you stream HD video then you’ll notice a bit of stuttering. In real life testing we rarely got peak 4G speeds over 30 Mbps.
Between Opensignal and Speedtest by Ookla we can say average 5G speeds on O2 lie between 110.9 Mbps - 127.97 Mbps. Again, they’re generally one of the slowest for 5G data speeds.
While their 5G will let you stream comfortably, speeds can suffer if you’re on the fringes of 5G signal. If sheer speeds are what you need, you might be better off looking elsewhere.
Useful link: More about O2's 4G
“Since there are no speed caps on Tesco, you’ll get the same speeds with them as you would on O2. In the end, neither are outstanding for speeds but are generally good enough for most people.”
O2 broadcast their call signal (3G/2G) on frequencies that are good for getting through building materials. Even so, you might still get poor signal indoors if you’re far from a mast. In this case, WiFi calling and 4G calling are helpful.
Unfortunately, Tesco Mobile are one of the few providers to still not offer either WiFi calling or 4G calling. O2 offer both, as do Sky Mobile who are a cheaper alternative who are also on the O2 network.
But O2’s scheme isn’t flawless. You can’t send texts over WiFi or 4G signal (only over call signal) a lot of Android models aren’t supported for the feature and it won’t work if you take one of their pay as you go bundles.
If it works on your phone it’s a good feature. You can also pair it with O2’s network of 15,000+ hotspots which you can use to connect to calls even on the London Underground.
Useful link: O2's guide to all their network features
Here’s another network feature you’re missing out on with Tesco Mobile. O2 offer a network of 15,000+ hotspots, while Tesco offer none. These are great for helping you save data on the go.
If you download their app your phone will automatically log you in to 7000 of their hotspots when you’re in range. Anyone can connect to their WiFi hotspots, but only O2 customers will get automatic connection.
You’ll be logged in automatically if the WiFi is faster than being on 3G/4G, but you can still connect manually if you want to save data. We like hotspots schemes that work quietly in the background, so we appreciate this.
It’s also great to get free WiFi on the London Underground, as that is a very common blackspot for many people. You’ll get automatic log in access on all of their pay monthly plans and pay as you go bundles.
Useful link: How O2's free WiFi works
“Going with O2 gets you some of the more advanced network features that a main network can offer - you’ll be going without if you join Tesco Mobile.”
While the other main networks (EE, Three, Vodafone) no longer offer free inclusive EU roaming, O2 do. You can access your UK allowance of minutes, texts and data in these 49 EU destinations.
For worldwide roaming, O2 offer their Travel Inclusive Bolt-on. This lets you roam in 27 worldwide destinations. However, it’s not a freebie. You either have to invest in a pricier plan or take it separately as an add-on (see costs here).
With the add-on you get 120 minutes, 120 texts and a small amount of full-speed data. If you use all that data they’ll let you keep using data without limits, though severely speed capped, at no extra cost.
O2 aren’t the best mobile network for roaming in our eyes, but their inclusive EU roaming is good and their worldwide roaming options won’t put you out of pocket like some networks will.
Useful link: All other roaming costs on O2
Tesco Mobile are currently joint-first in our rankings for best roaming networks. With them you can access your UK allowance of minutes, texts and data in these 48 EU roaming destinations.
What makes their roaming great is that you can use up your entire monthly allowance of data if you so wish. O2 cap your data allowance at 25GB while in the EU if your allowance is over that amount.
Now, if they think you’re gaming the system to use data for non-personal use, then they will investigate. But normal users won’t have to worry about that, you’d have to use a massive amount of data to raise suspicion.
If you’re going further afield then you’ll have to top up and pay as you go at some pretty steep rates. But Tesco are a brilliant choice for EU travellers, whether it’s a long stay or just a short trip.
Useful link: Full information on roaming with Tesco Mobile
“We’d say Tesco are the better network for EU roaming and O2 are the better network for worldwide roaming. While O2 do cap you at 25GB in the EU, that’s still more than what most people will get through. But overall, they’re both strong choices.”
If you’re in a tight-knit group of people such as a family or friends, then taking a group plan with a mobile network can be a great way of saving money overall. O2 offer simple discounts on extra plans added to your account.
You’ll get 20% off any pay monthly SIM only or phone contract added to your account. For phone contracts it’s only the usage (mins, texts, data) part that is discounted, but that’s nothing to scoff at.
Since O2 are a fairly pricey network in general, this can potentially save you a lot of money. You can potentially add up to 20 new users, but you’ll have to have very good credit to be accepted for that.
If you’re on a Sharer plan you can share data with users on your account. But these aren’t available to buy anymore.
Useful link: Calculate Family Plan discounts
Tesco will give you extra benefits to choose from for adding new users onto your account. You add up to four extra users and each will get a benefit of their choice.
You can choose to add extra data, extra Clubcard points, money off your monthly bill, discounted phone insurance and other benefits, which you can chop and change every month.
While some networks might get you bigger discounts, Tesco offer a nice amount of flexibility to get the benefit you need. We rate it highly as a family discount scheme.
There’s no hassle with changing your benefit month to month. If you don’t want to change it you don’t have to do anything. Overall it’s a great scheme for some peace of mind.
Useful link: How Family Perks work on Tesco Mobile
"Both networks have some decent options for families. It’s about finding what combination works best for you on the two providers."
On any of O2’s plans you get access to their highly popular Priority rewards scheme. It’s offered on all SIM only and phone contracts as standard.
It’s an app that gives you new special offers, discounts and freebies for high-street shopping, restaurants and experiences. These change every week so you’re always getting something new.
You also get priority access (hence the name) to events and concerts hosted at O2 sponsored venues, such as the O2 arena (see the sorts of thing here).
We think it’s definitely the best scheme of its kind (both Vodafone and Three offer something similar) and it’s a great way of getting extra value out of your plan.
Useful link: O2 Priority help guide and FAQs
If you do most of your shopping at Tesco and you’re a Clubcard holder, you can get some great benefits by joining Tesco Mobile. The first benefit is you get immediate access to exclusive deals on SIM only and phone contracts.
You can also connect your Clubcard to your Mobile account in order to start earning Clubcard points from your monthly mobile bill. And you can use the Clubcard points you earn to get money off your monthly bill.
In order to get money off your bill you’ll have to earn a certain amount of points. And the vouchers you earn from your Clubcard points will be worth double on Tesco Mobile (so a £2 voucher will get you £4 off your bill). Read how it all works here.
We think it’s a great scheme, as you can create a cycle of spending and earning points to get money off your bill and your shopping. But you have to be loyal to Tesco if you want to make the most out of it.
Useful link: How to join your Clubcard and Tesco Mobile accounts
“Even if you’re not a dedicated Tesco shopper, you can earn some money off Tesco Mobile by collecting points and benefitting from Clubcard prices. O2’s benefits are geared towards making you spend more or saving you a spare pound here and there.”
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O2 offer many of their phone models on what are called “Refresh” contracts. These split the cost of paying back your phone and paying for your usage (minutes, texts and data) into separate bills that you pay together.
This means you can pay off the cost of your phone early if you want to upgrade, and you can change or leave your usage plan if it doesn’t suit your needs.
Their Custom Plans also give you a great amount of flexibility. With these you can set an upfront cost to your needs (there is a minimum) and set a contract length between 3 and 36 months.
No matter what you choose, the cost of your phone actually stays the same, so there’s no wrong combination that will have you paying more. However, you might be denied if you have any marks on your credit history.
Useful link: Read O2's guide to their Custom Plans
Tesco offer fairly cheap phone contracts, while also offering a decent degree of flexibility some of their models are offered on Anytime Upgrade Flex contracts, but most are offered as standard 24-month contracts.
Theirs work similar to O2’s. Your phone and usage are paid as separate payments to make your monthly bill and you can set contract lengths and upfront payments how you want.
You don’t get as much flexibility to choose your contract length as you would on O2, but no matter how long your contract, you’ll still end up paying the same amount for your phone. You can change your usage plan whenever.
So you get a little less flexibility than being on O2, but you generally get cheaper deals which you can make even cheaper by using Clubcard points to get money off your phone contract.
Useful link: iPhone | Samsung Galaxy | Other makes
"Tesco Mobile offer generally cheaper phone contracts, while O2 offer you a bit more flexibility. We think saving money overall will be more important for most people, so we think Tesco are just a bit better here."