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Sky Mobile vs Three: compare their 4G/5G networks & benefits

Sky and Three logos with a versus symbol

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We see if you're better off joining Three or Sky Mobile on a SIM only deal or phone contract and compare coverage, speeds and other features. Last updated: 30th November 2021.

In our Sky Mobile vs Three guide

Latest offers

Three and Sky Mobile's networks

Do Sky Mobile or Three have better coverage?

We look at which has the biggest 3G/4G/5G network

Mobile signal bars with Three and Sky logos

Sky 4G/3G/2G coverage is generally better

Sky Mobile and Telefonica logos


See press release

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While Three operate on their own network, Sky have an agreement to use O2’s. We think either networks have their pros and cons for coverage between them:

Sky hold a clear advantage for call signal. Indoor signal is generally better on Sky and you’ll find fewer blackspots out in the sticks as they have more of the UK’s landmass covered.

We’d say Sky also win out for 4G coverage. But when you’re in larger towns and cities you’ll hardly notice a difference. The differences only become apparent in rural areas.

It’s always worth it to check each network's coverage using their official maps below to see which one has the better coverage in the areas you’re expecting to use your phone.

Useful link: More about Sky's network

Three have a better 5G network

Three branded map of the UK with 5G pointers

Read latest 5G news

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Three are the network that has really gone all in for 5G, more-so than any other UK network. They cover more locations than Sky, while having the fastest 5G speeds by far.

Three have 5G in a massive 300 places listed here, while Sky have it in these 150+ locations. There is some overlap, but some areas are covered by one and not the other. They also cover these places on a street by street basis.

Here’s our pick of the best value deals with 5G included:

While they say they cover certain cities, you’ll only be able to get 5G in specific locations in those cities (check street-by-street here). These areas tend to be the busiest ones where 5G is needed the most.

Getting 5G is simpler on Three as you’ll get it automatically on all but their smallest plans. It’s free to get on Sky, but you have to fiddle around with your account settings. This shouldn’t be necessary as it’s already free.

Useful link: How to get 5G on Sky Mobile

Sky and Three network maps

Check everywhere you'll use your phone, not just at home

Sky coverage checker

Sky Mobile map

Check Sky signal

using their official map
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Three coverage checker

Three network map

Check Three signal

using their official map
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Our verdict on coverage:

Minor win for Sky Mobile

"Three have more than twice the number of covered towns and cities. Sky’s coverage is undoubtedly great, but it can’t quite reach Three’s level."

Compare pricing and deals

5G/4G data speeds on Sky vs Three

Which provider has faster data?

Speedometer icon with Sky and Three logos

4G on Three measures up faster than Sky

Hello 5G banner

How 5G will help

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We look at the results of Opensignal and Speedtest by Ookla, who take millions of measurements around the country from volunteer smartphones, in order to see which networks are the fastest.

They’ve consistently put Three above Sky’s hosts O2 in terms of 4G speeds for a while now (and we found little difference between Sky vs O2). Here's how they compare:

Customers on Three typically received 4G speeds around 25.2 Mbps. O2 users got around 17.1 Mbps, though these are average results. Your speeds will depend on location.

For your average browsing needs, checking emails and social media and so on, you’ll not likely notice a difference. But for more data-heavy activities, Three should be the better choice.

Useful link: What Three say about their network

5G speeds on Three are lightning fast

Three's fastest 5G network banner

Read why

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By looking at Speedtest’s results we can see that Sky users (through the O2 network) can expect typical speeds of around 141.28 Mbps on 5G. But you could see even faster speeds in certain areas.

But Three claim to be the fastest UK 5G network, and their claims aren’t too far from wrong. Speedtest claim they have the fastest 5G speeds in the country and typical speeds of a lightning fast 221.81 Mbps.

It’s been a while since 5G has been established on either, so we have no doubt that these readings are accurate. But bear in mind speeds may depend on where you use your phone.

Useful link: Our guide to the best 5G networks

Our verdict on data speeds:

Win for Three

"The results of the independent testers speak for themselves. Three are certainly the faster for typical speeds, though max speeds may be similar between the two."

Compare pricing and deals

Extra network features on Sky vs Three

Who has better extras to keep you connected?

WiFi calling icon and Sky and Three logos

Both Sky and Three have WiFi calling

Three WiFi calling banner

Check phone support

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WiFi calling is a network feature allowing your phone to connect to calls via WiFi signal instead of conventional call signal (3G/2G). It’s offered on both of these networks as standard.

As Three have offered if for longer they are able to offer it on more phone models (we found it also works with more phones than Three actually list here). You can also send/receive SMS messages via WiFi.

Sky Mobile's list of supported devices is smaller. It’s also worse functionally as you can’t send/receive SMS messages and if you lose WiFi signal, we found your call drops (you’ll be transferred to 4G signal on Three).

It’s a double edged sword as Three have the better feature by far, but Sky’s call signal is better at getting indoors anyway so it’s not as necessary. Check your phone is covered in any case.

Useful link: 4G calling on Sky

Both networks offer some WiFi hotspots

Sky WiFi banner

How to connect

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Between Three and Sky, only Three get you free access to WiFi at Underground stations. This is made available on all of Three’s pay monthly plans, even the very cheapest ones.

Sky offer the Sky WiFi network of nationwide hotspots in popular areas like pubs and cafes. But they’re already free to access to there’s no exclusive benefit being a Sky Mobile customer for this.

Free WiFi hotspot access with your mobile deal is especially nice for lower data users who want to hold onto their limited data amount, but also helps you connect in places you might otherwise not be able to.

It’s not a massive deal, however. Free WiFi is becoming more and more common in pubs, malls, restaurants and so on. WiFi hotspots aren’t the only way to stay connected on the go.

Useful link: Costs for going over your limit on Three

Our verdict on network features:

Minor win for Three

"Three’s WiFi calling is just that little bit better than Sky’s and their WiFi hotspot network actually gives you a reason to join them, where Sky’s isn’t exclusive to their customers."

Compare pricing and deals

Benefits on Three vs Sky Mobile

Free streaming data: Only Sky offer it

How does Sky’s unlimited streaming data work?

Streaming smartphone with Three and Sky logos

Unlimited data for streaming Sky TV apps

Devices with unlimited streaming lettering

Read full guide

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If you’re an existing Sky TV customer, there’s a brilliant benefit to joining Sky Mobile as well to help you get the most out of your TV package:

Sky Watch gives you an unlimited data allowance to stream all of Sky's TV apps (see the full list), as long as you have them in your home TV package.

What’s even better is that it’s included on all of Sky’s plans (phone, tablet or SIM only) meaning you can take the very cheapest data plan and stream as much as you want with it:

There are a couple of limitations. Adverts will sometimes come out of your data (depending on the app) and you’ll have to have some data left over for it to work (at least 50MB). Other than that it’s an amazing benefit.

Three used to have something similar for certain apps, called Go Binge, but they binned it a while ago. It’s a shame because it was a really good scheme, giving Sky an automatic win.

Useful link: What the Sky Go app can do

Our verdict on free streaming:

Automatic win for Sky

"Since Three have binned their Go Binge scheme, Sky get an automatic win. That takes nothing away from how brilliant Sky’s scheme is, because it is definitely one of the best out there."

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Roaming compared on Three and Sky Mobile

Which network is better for going abroad?

A globe with Sky and Three logos

Sky don’t offer inclusive EU roaming at all

Sky Mobile roaming banner

What you get

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Fewer and fewer networks are offering free inclusive EU roaming these days, and Sky Mobile have joined the networks that have got rid of their roaming schemes. You now have to pay a daily rate to roam in the EU.

This is currently £2 for every day you’re in one of their EU destinations. There are no special passes or benefits to get around paying it, and that can add up to a lot if you’re on a long holiday.

Add to that the fact that their free streaming data benefit doesn’t work abroad and there are fewer and fewer reasons to like Sky’s roaming policy these days.

But you can roam beyond the EU in their covered worldwide destinations at the same £2 daily rate. Compared to other networks that’s actually decent value, so that’s good news if you’re a worldwide traveller. Otherwise, Sky aren’t great.

Useful link: Full roaming costs per country on sky

Three have got rid of their excellent scheme

Expired stampThree Go Roam banner

What Three say

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Three have fallen from their first-place throne among the best roaming network rankings. They used to offer inclusive roaming in 71 EU and worldwide destinations. Not any more.

We think it’s still worth a mention as you’ll still benefit from this if you are a long-term Three customer. But if you join them now you’ll only benefit until the 23rd May 2022.

After that, you’ll have to pay £2 a day to unlock your regular UK allowance in the EU and £5 a day beyond the EU in certain destinations.

When it comes to inclusive EU roaming the two networks are as bad as each other, but you won’t have to shell out quite as much to roam beyond the EU on Sky. It’s a small but decisive win for Sky here.

Useful link: Full roaming guide and all costs on Three

Our verdict on roaming:

Small win for Sky

"With the changes to Sky’s roaming scheme, the two networks have very similar EU roaming. But Sky are quite a bit better for worldwide roaming which just gives them the edge overall."

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Other extra perks on Sky vs Three

Here's what other benefits you get on each

A giftbox with Sky and Three logos

Keep unused data on Sky and share it

Piggybank showing saved data

Read full guide

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Sky have made it so you can avoid wasting unused data you've bought as part of your plan with their piggybank system - a sort of bank account for spare data you've not used.

At the end of each month, they'll automatically calculate how much you've got left (if any) and put it into your piggybank. Then, if you ever run out of data during a busy month, you can make a withdrawal of 1GB at a time.

If you've got multiple mobile deals on a single account, you can even send data to someone else if they run out. Or you can trade it for discounts off new devices.

It helps you avoid ever paying extra for running out of data. And your saved data lasts 3 years, so you've got ages to use it up or trade it in. Three have nothing similar to this.

Useful link: Sky's full guide to their Piggybank system

Three’s benefit scheme is less impressive

Three benefit scheme

See example offers

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Three have introduced a customer benefit’s scheme after having not offered one for a while. It’s called Three+ and is offered to all Three customers.

By using their app you’ll get access to rewards in the shape of special offers on food delivery services, places to dine-in, cinema tickets and they’ve promised presale tickets for a as-of-yet unknown festival.

It’s a nice benefit to have, especially since it’s offered to all Three customers. But you don’t actually get to choose the offers you want, so if the offers don’t appeal to you you’re not really getting anything out of it.

Also, customers have reported issues with the app not working, not being able to log in or their offers not working in-store. It’s a new scheme so we expect a few bugs. Three have an FAQs page if you have any issues.

Useful link: Three’s own guide to their Three+ scheme

Prices and plans compared

SIM only on Sky Mobile vs Three

Do Three or Sky have better SIM only deals?

SIM card with Sky and Three logos



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Added features

Special offers on Three and Sky

Here's what's currently running on the two networks

Special offer ribbon with Sky and Three logos

Phone contracts on Sky Mobile vs Three

Which is better for joining on a phone deal?

Smartphone between Sky and Three logos

Sky offer greater flexibility with phone contracts

Screenshot of credit check

Read what's involved

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When you buy a phone deal from Sky you’re getting the overall cost of your phone and your minutes, texts and data as separate payments that are bundled into one monthly bill payment.

You’re able to choose a 36-month deal (for a lower monthly cost spread out over a longer period) or a shorter 24-month one (paid off more quickly and cheaper overall).

You can also upgrade early or pay off the remainder of your loan after your first 12 months are up. You’re even allowed to leave Sky early without cancellation fees after this time.

We're not so keen on the Swap trade-in part of Sky's phone contracts, as you’re giving up the phone you’ve paid for. But what is nice is that you can use your saved up unused data to get discounts on your next upgrade.

Useful link: Use our phone deal comparison tool

Three's phone contracts are much simpler

Screenshot of phone comparison tool

Compare phone contracts

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If you join three via re-sellers like Fonehouse you can get an even better value deal than going with Three directly (use our comparison tool to see the cheapest deals).

In any case, all of their phone contracts are your standard 24-month ones, where your phone and usage are all part of the same contract payment (they’re inseparable).

Contracts are less flexible than on Sky. Three don’t let you choose different contract lengths, nor can you upgrade early. But you can get some very good deals on Three, especially through re-sellers.

Use our comparison tool here to compare all major networks directly and via re-sellers like Carphone Warehouse and more.

Useful link: Three's current phone range

Our verdict on phone contracts:

Minor win for Sky

"It’s a manner of cost against flexibility. We rate flexibility very highly as the customer has more say over what they want. You might get a better overall deal on Three, but Sky’s flexibility gives them the edge."

Compare pricing and deals

More Sky Mobile articles

More Three guides