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SMARTY vs Three: all the differences between the two networks

SMARTY mobile vs Three

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We look at the differences between joining Three or SMARTY on a SIM only plan, including coverage, speeds, WiFi calling, prices and benefits. SIM Sherpa is your trusty guide. Last updated: December 7th 2020.

Latest news on offers

SMARTY and Three mobile network differences

Is coverage identical on SMARTY and Three?

We see if you'll get the same signal on both networks

Mobile signal bars with Three and SMARTY logos

Three and SMARTY are on the same network

SMARTY powered by Three banner

What this means...

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If you didn't know, SMARTY uses the Three mobile network. In fact, it's actually owned directly by Three themselves. Three is a mobile network in its own right, distinct from EE, Vodafone and O2.

Three is the smallest UK network in terms of coverage for calls and 4G data for the whole country. Outside built-up places, you may find yourself on 3G more often. And in the country, you can get blackspots.

On paper, that doesn't sound great. But it's worth using coverage checkers below, because if their network is good in the places you use your phone, the rest of the country is irrelevant.

We've tested a SMARTY and Three SIM card in the same test phones simulataneously. There's no difference in signal. You don't get an inferior 4G or 3G experience on SMARTY to Three. 5G is different (see below).

Useful link:
Three's latest network developments

Only Three has their 5G network live in 68 places

See latest places

(opens in new window)

Now that Three have switched on their 5G network, there is technically a difference in coverage between them and SMARTY, if you're an early adopter and have a 5G-ready phone.

5G is live on Three in parts of these 68 locations with more to come. We're still talking about a street-by-street basis, with coverage focussing on busy places like train stations, high streets and event venues.

SMARTY say they do have plans to add 5G but don't have a confirmed date, so currently only offer 4G and 3G. Three have included the faster 5G technology on all their plans at no extra cost, including pay as you go.

If you're toying between the two, you could take a 1-month deal on either and either wait it out.

Useful link: Latest 5G rollout news on Three

Use one of their coverage checkers

Don't just check at home - look at everywhere you'll use your phone

SMARTY network map

SMARTY reception map

Check SMARTY signal

using their official map
(opens in new window)

Three network map

Three's coverage map

Check Three signal

using their official map
(opens in new window)

Our verdict on coverage:

Technically a win for Three

"For most people with a 4G/3G capable phone, there's no difference in coverage between SMARTY and Three. It's the same network. But early adopters can only get 5G on Three, so there is technically now a difference."

Compare pricing and deals

4G data speeds on SMARTY vs Three

Are there any differences in download speeds?

Speedometer with SMARTY and Three logos

Expect typical downloads around 20 Mbps on both

Three fastest 5G banner

Latest 5G news

(opens in new window)

We'd say the Three network is one of the better choices when it comes to download speeds over a 4G data connection. They normally come in joint-second place in speed tests by independent testers.

Opensignal and Speedtest by Ookla take millions of measurements on people's smartphones with each network. On average they found Three customers get downloads around 21.60 Mbps.

That's like a decent mid-range home broadband speed. And will comfortably support things like HD videos without buffering. Our own testing suggests minimum speeds around 9 Mbps and a max around 43 Mbps.

We've taken a SMARTY and Three SIM card out in identical test phones and conducted simultaneous speed tests in different types of locations. We found no baked-in speed difference between SMARTY and Three.

Useful link:
SMARTY's policy on network throttling

Our verdict on data speeds:


"We haven't managed to find a speed difference between Three and SMARTY, so it's not something to consider currently. If Three launch 5G before SMARTY, then things could change."

Compare pricing and deals

Network differences between SMARTY and Three

Here are some network features you don't get on SMARTY but do on Three

SMARTY and Three logs with some cogs

Both SMARTY and Three now have WiFi calling

SMARTY WiFi calling banner

Read the blog

(opens in new window)

One of the key differences between joining Three and SMARTY used to be that you'd get WiFi calling and 4G calling on Three but you didn't on SMARTY. That's all now changed, as SMARTY's plans all now include it too.

If you don't already know, the feature lets you make/take calls and send/receive SMS over WiFi, if you're ever somewhere that conventional mobile signal can't reach. It helps end the problem of indoor blackspots.

So it's handy you get it on both networks, in addition to 4G calling (VoLTE), which both have too. This increases the amount of signal calls can work on (not just 3G) and improves audio quality too.

It does seem that Three's list of supported devices is bigger than SMARTY's. We'd view that with a bit of sceptism though. We can't see why there'd be a difference in real-life.

It could be that these are just the tested and confirmed devices for SMARTY. We'd be amazed if a phone that had worked with Three's WiFi calling didn't on SMARTY's.

Useful link:
All UK mobile networks with WiFi calling

Three get you free WiFi on the Underground, SMARTY don't

Three's WiFi on the Underground scheme banner

How to connect

(opens in new window)

If you're a regular in London, you'll know that most stations on the TFL network now have WiFi on the platforms, which you can either pay to use or get included with your mobile / broadband deal.

All Three customers can use the service for free, whether you're pay monthly or pay as you go (as long as you've used your phone in the last 30 days). Just sign in once and it'll remember you in future.

The service is a useful way to save data, although it'd be better if the trains themselves had WiFi too. It combines well with WiFi calling to make calls underground where signal would never reach.

Even though SMARTY do hint this is something that could be added in future, they don't offer it today. It's one of the ever-fewer differences between SMARTY and Three worth knowing.

Useful link:
Full details on Three's free WiFi on the Underground

Our verdict on extra network features:

Minor win for Three

"Now that SMARTY also have WiFi calling, the only network feature difference other than 5G is free hotspots on the London Underground, which is unlikely to be deal clincher for most."

Compare pricing and deals

Differences in benefits between Three and SMARTY

How roaming compares on SMARTY vs Three

Is SMARTY as good for going abroad as Three?

Globe with Three and SMARTY logos

Three's worldwide roaming massively trumps SMARTY's

Flags of recently added Go Roam countries

See full country list

(opens in new window)

Roaming is one area where Three have a built-in advantage over SMARTY, thanks to their well-known inclusive worldwide roaming scheme Go Roam, formerly known as Feel At Home.

While every network has to offer roaming at no extra cost in the EU, Three extend this to a total of 71 worldwide countries, including the USA and Australia (Three list all the included countries here).

Anyone's who's used their phone in these types of places knows the cost is often eye-watering on many networks. So if you travel long-haul regularly, the scheme is worth its weight in gold.

And we like the fact you get it on every pay monthly plan (phone or SIM) and even on pay as you go, when you buy a monthly Add-on (bundle). Three certainly beat what you get with SMARTY for long-haul.

Useful link:
Full roaming costs and terms on Three

SMARTY's roaming will suit anyone who stays in Europe

SMARTY EU roaming banner

See full details

(opens in new window)

If you're someone who mostly takes their holidays in EU countries, then SMARTY will probably comfortably cover your needs. They offer roaming at no extra cost in all these EU countries.

That means you can use all your normal minutes, texts and data while you're away, without paying extra. Although if you're on SMARTY's unlimited plan, you can only use a frankly huge 19GB data per month.

One word of warning if you are joining SMARTY: follow these instructions to activate roaming in your account before you go away. It's set to "off" automatically, so you could end up abroad without a way of turning it on.

If you do want to travel outside Europe, it's still possible, you just don't get any inclusive roaming there like on Three. Instead, you have to top up with credit and then pay as you go at these rates.

Useful link:
Full roaming costs on SMARTY and other important info

Our verdict on roaming:

A win for Three

"Roaming's one of the areas where Three's status as one of the UK's main network outclasses no-frills SMARTY. Although infrequent travellers and European-only holidaymakers will be fine on either network."

Compare pricing and deals

Benefits where SMARTY are better than Three

What do you get with SMARTY that you don't on Three?

SMARTY logo with greater than symbol and Three logo

SMARTY will pay you back for unused data on some plans

Data discount explanation

How it works

(opens in new window)

If you've had a pay monthly plan before, you'll know the feeling that you've wasted money, when you don't use all the data that your monthly plan gives you. Normally it's just too bad. But SMARTY have a nice solution:

On their "Data Discount Plans", they'll pay you back what all your unused data cost to buy in the first place, via a discount on next month's plan. So if you have 2GB left and that cost £2, that's what they'll pay you back.

Each of these plans pays you back £1 per GB of unused data each month:

SMARTY even calculate the cost down to the nearest MB (basically 1000th of 1GB), so you'll get back every penny and never overpay. We think this is the fairest such system in the UK today (better than data rollover).

This is SMARTY's main unique selling point. And is one of the advantages of joining SMARTY over Three, who don't offer anything like this on pay monthly or pay as you go.

Useful link:
SMARTY's help guide to the data discount

SMARTY's plans have no credit check and no contract

SMARTY no contract benefits

How billing works

(opens in new window)

All SMARTY's plans are paid for up front and last just one month. There's no contract - meaning if you get fed up, you don't have to give any notice, you just stop paying and your plan ends once your month's up.

You can't get that flexibility even on Three's 1-month SIM only contracts, where you still have to give 30 days' notice. Three's 1-month pay as you go Add-ons do work like SMARTY but are more expensive.

The other benefit of paying up front on SMARTY means that there's no credit check to join them (Three's pay monthly plans do need you to pass one). That's good if you have bad/no credit history or are new to the UK.

It's also impossible to spend more than your plan's basic cost, unless you top up with credit in advance. That helps you know what you're paying, although could be a chore if you have to top up to use a feature in a hurry.

Useful link:
How to manage your SMARTY plan

Three's benefits you don't get on SMARTY

Here's what you'd miss out on if you joined SMARTY instead of Three

Three logo, greater than symbol and SMARTY logo

Most of Three's extra benefits have been cut

Expired stampThree's Go Binge banner

Read statement

(opens in new window)

Previously in this section, we could list a whole load of added-value perks and benefits you'd get by joining Three instead of SMARTY but that list has been chipped away at in the last year, leaving the cupboard bare.

There's no unlimited video and music streaming scheme any more on Three, as Go Binge has been withdrawn. There's no Wuntu rewards app any more. Nor do you get Three's quirky easyjet upgrades scheme either.

You're pretty much left with better roaming and 5G as reasons to join Three over SMARTY (even WiFi/4G calling is now the same), plus their phone/stored-based customer service (see below).

If you're not fussed about any of those, the choice will come down to which has the best current deals and whether you want the flexibility on SMARTY of having just a 1-month plan.

Useful link:
How Go Binge worked

Customer service differences on Three and SMARTY

Which network is easier to deal with if you have a problem?

Person with headset with SMARTY and Three logos

Three's customer service record's got worse recently

Ofcom complaints data

How to get help

(opens in new window)

People complain to the telecoms regulator Ofcom, when a mobile network hasn't sorted their problem. So having a low number of Ofcom complaints, like Three, is a sign that they have effective customer services.

Per 100,000 pay monthly Three customers, Ofcom only receive 5 complaints, which is above the industry average. And it's got worse in the last year (it used to be 3).

There are loads of ways to contact Three if you have a problem. You can chat within their app, in your online account, or phone them. Also underrated is the ability to walk into a Three store on the high street.

If you're the sort of person who likes "to speak to a real person" when they've got a problem with a product, then Three definitely have more options than SMARTY.

Useful link:
All ways to get help on Three

SMARTY's customer service is online-only

Online chat transcript

How to get help

(opens in new window)

Here's another clear difference between SMARTY and Three. SMARTY are set up as a no-frills brand, which means they've cut costs by only offering online-based customer service.

They've got a pretty decent help section on their website with answers to common questions. But if that doesn't help, you'll need to use their online chat or social media messaging services.

They're open 7 days a week, 8AM to 8PM. But the pace of conversations with them can be quite slow, especially getting the first message through. They will email you if they can't immediately reply.

People who like the re-assurance of talking to someone on the phone, or even going in to a store to get face-to-face help, aren't going to like SMARTY if they ever need anything. Others will be content with online-only.

Useful link:
How to get help on SMARTY

Our verdict on customer service:

Win for Three

"If you like a helping hand off real people, Three are probably your best bet for customer service. On SMARTY, you'll need to be better at helping yourself."

Compare pricing and deals

Plans and pricing on SMARTY vs Three

SIM only deals: how SMARTY and Three compare

Do Three or SMARTY have better prices on SIM only?

SIM card with Three and SMARTY logos



Three logo
BT Mobile logo
EE logo
giffgaff logo
Honest logo
ID logo
IQ logo
Lebara logo
O2 logo
Plusnet logo
Sky logo
Talkmobile logo
Tesco logo
Virgin Mobile logo
Vodafone logo
VOXI logo


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Added features

How unlimited data compares on SMARTY and Three

Are both their deals truly unlimited?

Unlimited symbol between SMARTY and Three logos

SMARTY's unlimited plan is on a short 1-month contract

SMARTY unlimited plan

See the full deal

(opens in new window)

The main advantage of SMARTY's unlimited data plan (ignoring price) over Three's is that it's on a flexible 1-month contract. It means you're free to change plan or leave at short notice if you decide it's not for you.

You're also allowed to use the SIM directly in a tablet or iPad for unlimited mobile broadband, as well as using it in your phone for tethering (personal hotspot) too.

The main limitation is on roaming. If you're within the EU, you can only use 19GB a month while you're out of the country. This is currently the same on Three too.

Otherwise the principle is essentially the same: even if you used your phone for every minute of the whole month, there'd still be no charges for going over any data limits.

Useful link:
Compare current prices

Three's unlimited plans come with added benefits

Three unlimited data SIM only plan

See Three's plans

(opens in new window)

On Three you can choose between a 1-month contract that will normally work out more expensive than SMARTY, or a longer 12-month or 24-month deal, which are more similar in price.

The main advantage other than any price variations of Three's deals over SMARTY is that you get a few extras like inclusive roaming in 71 countries (not just EU ones), where you can use 19GB data.

Here are all the pay monthly options to get unlimited data on your phone with Three:

Unlike SMARTY though, you can't put Three's phone unlimited data SIMs in a tablet (the network detects it and blocks it). You have to buy a specific tablet SIM to do this.

Useful link:
Compare latest prices

Special offers on Three and SMARTY

Who's got the best promotions running currently?

Special offer label with SMARTY and Three logos

Phone contracts on Three vs SMARTY

You can currently only get a phone with Three but SMARTY could offer them in future

Smartphone with Three and SMARTY logos

Only Three currently offer smartphone contracts

Screenshot of Three's phone range

See phone range

(opens in new window)

We rate Three as an excellent place to take out a phone contract. You get everything we've talked about in our network and benefits sections above, and reasonable prices, especially with their hidden deals.

Three's phone contracts are straight-up 24-month deals - there's no financing like you get with some networks, which also means there's no real early upgrade offers either.

They've got all the iPhone and Samsung models you'd expect from a mobile network, and quite a few other Android handsets too. Use our price comparison tool below to see how Three compare for each model.

Until SMARTY start offering phone contracts, we can't really compare Three with them.

Useful link:
See Three's range of pay monthly phones

Phone contracts on SMARTY could be coming down the line

Get your next phone from SMARTY banner

See blog post

(opens in new window)

Today, SMARTY are only set up as a SIM only provider. But this blog post suggests that they're working on offering phone contracts in the future.

We'd expect SMARTY's phone contracts to work a lot like Vodafone's sub-brand VOXI's, where you take out a separate agreement for the cost of your phone and your minutes, texts and data plan.

The advantage of this way of doing phone contracts is that you get flexibility from having a phone plan you can pay off more quickly or slowly. And it lets you upgrade early by paying off the phone in full.

The blog post originally said, SMARTY would be offering phone contracts in 2019. That now seems to be running late. But we'll update this section when anything changes.

Useful link:
Compare phone contracts from all networks

Choose a manufacturer

Which make of phone do you want?

Find a plan for your phone

Choose what you want from your deal

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Data speed (3G or 4G) >
Max contract length >
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Choose which networks you'd consider:

Three logo
BT Mobile logo
EE logo
giffgaff logo
ID logo
O2 logo
Sky logo
Tesco logo
Virgin Mobile logo
Vodafone logo

Our verdict on phone contracts:

Three win by default

"You can currently only get a phone contract from Three, so they're your only choice for now, so win this category by default."

Compare pricing and deals

Making your mind up

How to decide between Three and SMARTY

SMARTY vs Three

Decide what you value most

For us, the key is working out what is important to you. Have a look at our summary a bit further down.

Use our deal finder above to look for deals with the number of mins, texts and data you want. Then see how the prices compare. It won't always be the case SMARTY are cheaper.

If Three are cheaper and you're happy with the contract length, you'll get a few more network extras with their plans. But if the SMARTY benefits are more important then that's who to go with.

SMARTY are generally better for...

If you want ties no longer than 30 days

You're not 100% sure how much data you need

You want a plan where you can't overspend

You've failed credit checks before (there are none)

Jump to

Three are generally better for...

Inclusive worldwide roaming

5G data

Plans with larger data allowances

More human customer service

Jump to

More articles about Three

More SMARTY articles