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BT Mobile vs Three: 4G/5G coverage, speeds and benefits

BT Mobile vs Three

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We compare Three against BT Mobile to see which you're better off joining, for the best network coverage, 4G speeds and deals. Here's what we found. Last updated: 7th March 2022.

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Which has the better network?

Coverage: do BT Mobile or Three have a bigger network?

A look at whether you can expect better signal on Three or BT Mobile

Three and BT logos with some mobile signal bars

BT Mobile have much better 4G coverage

Big Network Build lettering in Three brand

Read expansion plans

at three.co.uk
(opens in new window)

While Three own and operate on their own network, BT use EE’s network for call and data signal. In fact, BT group actually own EE. Each has its pros and cons for mobile reception:

Neither network has much of an advantage in terms of overall call signal coverage. In our testing we found fewer total blackspots on BT than on Three, but this will vary per location. Both networks’ signal can suffer indoors.

But BT have a big advantage in 4G data coverage. They cover more of the UK’s geographical landmass and more places where people actually live, so you’ll have a better chance of staying connected on the go.

There’s basically no 4G difference in big towns and cities. It really depends on where you live, so using their coverage checkers is a good idea to see what sort of coverage you can expect from either network.

Useful link: Three's 4G network expansion plans

5G available in more locations on Three

BT Mobile 5G explainer video screenshot

Watch 5G guide

at BT.com
(opens in new window)

There’s two ways of looking at 5G coverage. You can look at which network covers more towns and cities, or which network are able to offer better coverage within their declared locations.

Three may have 5G in 300+ places against BT’s 160+ locations, but having almost twice the number of locations doesn’t tell the whole story. How well do each network cover their declared locations?

Well, BT and EE only report a location as covered when 50% of its area gets 5G. By using either network's coverage checkers you’ll notice Three’s coverage of their declared locations can be quite a bit patchier than BT’s.

Since BT don’t declare all their locations, you might still be covered even if your location isn’t already named on their list. Either way, use their coverage checkers to compare them in your area.

Useful link: Our guide to the best 5G networks

Use Three and BT's network maps

It's worth giving their signal a double check everywhere you'll use your phone

Three's coverage map

Three coverage map screenshot

Check Three signal

at Three.co.uk
(opens in new window)

BT Mobile's coverage map

BT Mobile coverage map screenshot

Check BT coverage

at BT.com
(opens in new window)

Our verdict on coverage:

Win for BT Mobile

"Having better 4G coverage is important, but we’d argue BT’s total mix of coverage is better overall. Even though Three claim to cover more locations with 5G, BT cover their locations more thoroughly and may have more locations than they claim."

Compare pricing and deals

Data speeds: are Three faster than BT Mobile?

A look at the expected download speeds on each network

BT and Three logos with a speedometer

BT Mobile have much faster 4G than Three on average

Three's Real 5G network banner

What BT say

at BT.com
(opens in new window)

You’ll likely spend most of your time on 4G signal, so it's important for networks to give the fastest 4G possible in the most amount of areas possible. We took results from independent testers Opensignal to compare the two:

They claim average speeds on BT’s hosts to be around 44.0 Mbps and speeds on Three to be around 25.2 Mbps. That’s a massive difference between the two and should be noticeable when downloading files or streaming videos.

In real life tests, we found Three could really suffer in suburban areas, going down to around 10 Mbps. But Three’s speeds consistently hovered around 44 Mbps in city centres and even some rural areas.

The lowest we got on BT was around 10 Mbps in very rural locations. But in the city centres on 4G+ we measured speeds well over 100 Mbps, which is almost as fast as 5G. Expect faster peak and average 4G speeds on BT.

Useful link: Read our BT Mobile vs EE guide

Three's 5G is by far the fastest in the UK

5G owned. We're building the fastest 5G network banner

Why they're faster

at Three.co.uk
(opens in new window)

While 4G might be the more important to look at, we also can’t ignore Three’s brilliant 5G speeds that leave most other networks in the dust. We took results from Opensignal and Speedtest by Ookla to compare:

BT’s hosts measured around 131.9 Mbps - 158.30 Mbps which is already brilliant, but it cannot touch Three’s speeds of around 103.9 Mbps - 246.65 Mbps. Peak speeds on Three are lightning fast.

Three claimed they can provide the best 5G because they’ve bought more of the radio spectrum (read Three's full explanation here). There’s a bit more variation in their speeds, but they should generally be faster than BT.

Bear in mind that 5G is always a changing game, and we might see the other networks catching up to Three. But for now, Three are the winners for pure 5G speeds.

Useful link: Next steps in Three's 5G rollout

Our verdict on data speeds:

A win for BT Mobile

"While 5G is getting more available as time goes on, for now most people will want the best 4G speeds possible. For that, it’s hardly a contest. And while Three have the best 5G speeds, BT aren’t too far behind. Overall BT have the better mix of speeds."

Compare pricing and deals

WiFi calling: which network has the best feature?

Making calls over WiFi when there's poor signal

WiFi calling symbol with BT and Three logos

Three’s WiFi is incredibly flexible

Three inTouch WiFi calling scheme

How it works

at Three.co.uk
(opens in new window)

One downside of Three’s call signal (3G/2G) is that the frequencies they’re broadcast on aren’t ideal for getting into buildings. So they need extra technology to help out with this.

To fix their poor indoor signal, Three have a brilliant WiFi calling feature that lets you make/take calls and send/receive SMS messages over WiFi signal. They also offer 4G calling (VoLTE) to do the same with 4G signal.

Three have one of our favourite WiFi calling features as it’s available on a wide range of phone models (even ones not bought from Three directly) and is offered on all pay monthly and pay as you go plans as standard.

While Three don’t claim to cover Android models not bought from them, the ones we tested worked just fine. You’ve got a good chance of WiFi calling working on Three.

Useful link: Three's full guide to their WiFi calling scheme

BT Mobile's WiFi calling is also great

BT WiFi calling

See supported phones

at BT.com
(opens in new window)

BT also have poor frequencies for getting indoors and actually get joint-first ranking in our list of the best networks for WiFi calling alongside Three. So what are the differences between them?

There’s not many. Their list of supported devices is pretty similar, but BT claim to cover a couple fewer Android models. Still, the Androids we tested that weren’t bought from BT directly worked just fine.

But really, both are pretty similar experiences. You can send and receive SMS messages, calls won’t drop when transferring from WiFi to 4G and it also comes on all plans at no extra cost.

The major upside to BT’s WiFi calling is how well it combines with their brilliant WiFi hotspot scheme and their 4G calling also combines well with their great 4G coverage. But both have basically the same WiFi calling overall.

Useful link: Check supported devices

Our verdict on this WiFi calling:


"We’re only looking at how WiFi calling works as a feature, not at how it pairs with coverage or WiFi hotspots. So, there’s basically nothing to separate the two networks on. It's brilliant on both."

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Free hotspot access on Three and BT Mobile

We compare what free WiFi each provider offers

WiFi symbol with BT and Three logos

BT Mobile have the largest WiFi hotspot scheme in the UK

BT WiFi app with a hotspot map

See hotspot locations

at BT.com
(opens in new window)

We really like it when networks offer a WiFi hotspot scheme to provide free WiFi to their customers on the go. The best networks for this will provide the most hotspots, the best signal and let customers connect automatically.

BT do all of these very well. They provide the largest network of WiFi hotspots with over 5 million around the UK and will automatically log you into the nearest hotspot with their app.

You’ll find these hotspots in busy areas where mobile signal could usually slow down due to congestion. Generally you’ll get them in restaurants, shopping centres, airports and transport hubs.

As a BT Mobile customer you get full, free access to these hotspots on any plan. The only downsides are that they can be slower than 4G and you don’t get any hotspots on the London Underground.

Useful link: More about free WiFi on BT Mobile

Three offer hotspots only on the London Underground

Three WiFi on the Underground banner

How to access it

at Three.co.uk
(opens in new window)

While Three don’t offer a wide network of WiFi hotspots like BT do, they carve out their own niche by providing WiFi hotspots on the London Underground.

On any of Three’s plans you’ll get free access to a network of over 250 hotspots at various stations and ticket barriers on the London Underground. Unfortunately there’s no free WiFi on the trains themselves.

It’s a great feature as you can stay connected to the internet and to calls and texts (using their WiFi calling) in a place that mobile signal usually can’t get to. Since BT don’t offer it, Three might be a better choice for London commuters.

And one consolation for their lack of overground WiFi hotspots is that there’s so much free WiFi out there anyway these days that you’re not really missing out on that much.

Useful link: Get free WiFi on the TFL network via Three

Our verdict on free hotspots:

A win for BT Mobile

"BT’s WiFi hotspot scheme will be more useful to more people. While Three have a nice little niche with their TFL hotspots, in the end 5 million+ is a lot more than 250+. BT are better at saving you data on the go."

Compare pricing and deals

Which offers the better perks and extras?

Inclusive roaming on Three and BT Mobile

Which has the better roaming scheme?

Globe with BT and Three logos

Three no longer offer inclusive roaming

Expired stampThree Go Roam banner

Read statement

at Three.co.uk
(opens in new window)

Once upon a time, Three easily had our best-rated roaming scheme. But now, with many of the other major providers, they’ve pulled their inclusive roaming altogether.

You now have to pay a daily fee of £2 a day in the EU and £5 beyond the EU to access your regular allowance of minutes, texts and data. That can get expensive fast.

Add to that the fact that you’re still limited to 12GB while abroad. After that you’ll start paying extra charges. That’s a decent amount for a short trip, but we think it’s ridiculous paying to access your allowance only for it to be capped.

Instead we think you’re better off joining Three’s low-cost brand SMARTY who offer inclusive EU roaming on all of their plans.

Useful link: Read Three's guide to roaming

BT Mobile still offer inclusive EU roaming as standard

BT's Roam Like Home banner

See countries list

at BT.com
(opens in new window)

BT have kept their EU roaming scheme largely in place since Brexit. On all of their plans you’ll be able to access your UK allowance of minutes, texts and data (see the full list of destinations here).

There is a fair usage cap of 50GB while abroad if your plan is over that amount. If it’s under you can use your full amount. That’s a pretty massive amount, but if you get through it you’ll pay per MB at these rates.

Beyond the EU you’ll have to pay for a pretty pricey Travel Data Pass, which currently gives you 500MB per day for £6 a day. That’s a lot to pay for not a lot of data. We think there are better options for worldwide roaming.

In our real-life BT review we found roaming on BT in the EU to be a pretty slick experience. It worked automatically and we got 4G in most places.

Useful link: Learn more about Roam Like Home

Our verdict on roaming:

A win for BT Mobile

"BT cover the cost of EU roaming as standard while Three don’t, and their fair usage policy is more reasonable. Worldwide travellers should probably steer clear of both."

Compare pricing and deals

Free entertainment extras

Do Three or BT Mobile have the better freebies?

Streaming phone with Three and BT logos

BT Mobile offer BT Sport app for free on some plans

BT Sport banner

Full offer terms

at BT.com
(opens in new window)

By far, BT’s best “freebie” is their offer of free access to the BT Sports app. But, bear in mind that “free” here only applies to certain plans. You’ll only get it on somewhat pricier deals:

Any SIM or phone deal costing £15 or more (broadband customer prices) gets you free access to the BT Sport app on your mobile.

With this you can watch live sport covered by BT Sport and there’s a few extra features like highlights and sporting news.

A big downside is that you can’t cast the app onto a larger screen, so you can only watch on your app. It’s also not a free unlimited data streaming service like some networks give you, it will eat through your data.

Useful link: How to get it when you join

Three have got rid of their free streaming data

Three Plus rewards app

How to get it

at Three.co.uk
(opens in new window)

The main networks try to add a little more value to their deals to help offset the fact you’re generally paying more for their deals. O2 have their Priority app, Vodafone have VeryMe, but what to Three offer?

On any Three plan you’ll get access to their new Three+ rewards app. For now the list of venues and restaurants covered by the app is fairly small but there’s a few offers on their you might like (see the full list here).

They also say that Three+ users will get presale tickets to a as-yet-unknown concert. But for now the app won’t astound you. More and more offers will become available, so keep an eye out.

We’d say it’s not yet as good as their old Wuntu app, nor does it make up for the benefits that they’ve stripped away. But it’s a nice sweetener on top of your deal.

Useful link: Our full guide to Three+

Our verdict on extra perks:

Win for BT

"Only BT are offering any form of entertainment extras, so its a win by default for them."

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Family plans compared on BT Mobile and Three

Which is best for taking out multiple contracts with?

A family plus BT and Three's logos

BT's Family SIMs give extra discounts on added SIMs

BT Mobile's Family SIM banner

Calculate discounts

at BT.com
(opens in new window)

If you’re a parent and your kids are getting old enough to use a phone but not old enough to pay for their own plans, you should consider family mobile plans. Some networks give you discounts for taking multiple SIMs on one account.

BT offer a brilliant Family discount. After signing up on a plan you can add up to 4x extra SIM only plans on top of that. With each added SIM you get a bigger and bigger discount (calculate savings here).

What’s great is that all the added SIMs are on 1-month contracts. That gives you the flexibility to add or drop them whenever you please. It makes dealing with different contract end dates a lot simpler.

The biggest drawback is that all the Family SIMs have to be the same data amount as the main account holder’s plan, which isn’t realistic for most families. You also can’t add discounted phone or other device contracts.

Useful link: Read our full review of BT's Family SIMs

Three offer discounts on phones and SIMs

Three existing customer offers screenshot

See customer deals

at Three.co.uk
(opens in new window)

As we said above, BT’s Family Plans don’t get you discounts on devices, just SIM only plans that all have to be the same data amount. And working out the savings can be head scratching.

Three offer a bit more flexibility. If you have an account on Three with an existing plan you can add extra SIM only or phone contracts with discounts on any added plan (see prices per plan here).

This typically only works out at about £1 a month off on SIM only plans. Or if you add a phone contract then you’ll probably get around £1 or £2 off and your upfront cost might be waived too (see existing customer phone offers here).

Those savings aren’t nearly as significant as BT’s, but they’re nothing to scoff at either. You also get the benefit of having all of your deals under one account, even phone deals, and £12 off a year is nothing to turn your nose up at.

Useful link: See Three's existing customer offers

Our verdict on family plans:

A win for BT Mobile

"We like the fact that both networks reward their customers for adding extra plans to their account (not all networks do). But you could end up saving a lot more with BT, which is the whole point of a discount."

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Which has the best deals?

SIM only: how BT Mobile and Three compare

Use our comparison tool below to see how BT Mobile and Three's similarly priced plans compare:

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Special offers on Three and BT Mobile

Here are the promotions currently running on both networks

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Phone contracts: BT Mobile vs Three

We look which network you're better off taking a smartphone from

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BT and Three's phone contracts work similarly

Screehot of our phone comparison tool

Compare phone deals

at simsherpa.com
(opens in new window)

BT and Three structure their phone contracts in basically the same way. You get a 24-month contract where you pay both the cost of your phone and usage (mins, texts, data) in one payment. We call these “traditional contracts”.

This means there’s no early upgrade schemes. You have to wait out the entirety of your contract. You also can’t pay lump sums to reduce your monthly payment or change your usage plan.

For prices, Three are generally more competitive. BT broadband customers get the £5 discount but that’s hardly a consolation. You can also get a Three contract through a third party retailer (compare prices here).

You get the same pay monthly benefits as we’ve gone through above, so factor that into your decision too. You can use our comparison tool below to compare prices on certain phone models.

Useful link: Compare phone contracts with us

Our verdict on phone contracts:

Three normally cheaper for phones

"Three generally offer the cheaper phone contracts and have a much wider range of available models. BT have generally been cutting back on phone contracts in recent times, so Three are the better choice."

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Other BT Mobile guides

Other Three guides