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iD Mobile vs SMARTY: two cheap networks on Three compared

SMARTY and iD Mobile logos

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Both SMARTY and iD Mobile use the Three network. But which offers the best all-round experience and benefits with their plans? Last updated: 29th November 2021.

In our SMARTY vs iD Mobile guide

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SMARTY's vs iD Mobile's networks

Is coverage identical on iD Mobile and SMARTY?

We check whether there's any signal differences between them

Mobile signal bars with iD and SMARTY logos

4G/3G coverage is the same on iD Mobile and SMARTY

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What this means...

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Both SMARTY and iD Mobile use Three’s network. While SMARTY are directly owned by Three, iD Mobile are owned by Carphone Warehouse. You’ll get Three’s 4G and 3G signal on both (but no 2G call signal).

Three is unfortunately the smallest major UK network. But they still get their 4G to 97% of UK residences and their 3G call signal to 99% and are expanding day by day both indoors and out.

We tested a SMARTY SIM and an iD SIM both against each other and against a Three SIM in various locations. Wherever we went we found no difference in the number of signal bars between them.

You may have issues with signal coverage outside of the big towns and cities. We recommend checking signal with either network here before signing up to check if there's 4G/3G in the places you plan to go.

Useful links: Our full SMARTY review | Our full iD Mobile review

Both networks now have 5G

iD 5G banner

Check supported phones

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Now that SMARTY have 5G, iD no longer hold an advantage over them for this. The two are now identical in terms of 5G coverage.

This means you’ll get 5G in the same list of 300+ towns and cities as you would on Three. This is brilliant for both networks as Three have the largest 5G network in the UK (by location count).

5G connection is still on a street by street basis, meaning you won’t get it all over a covered location. You can check 5G coverage using either networks’ coverage checkers below.

The main difference between the networks is that iD don’t support the same phone models as Three, as they need to preload their software onto the phone. To get 5G you’ll have to buy a supported model directly from them.

Useful link: Our guide to the best 5G networks

Check signal with either provider

Don't just test coverage where you live - but everywhere you'll take your phone

SMARTY's network map

SMARTY coverage checker screenshot

Check SMARTY signal

using their coverage checker
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iD's network map

iD Mobile coverage checker screenshot

Check iD signal

using their coverage checker
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Our verdict on coverage:

Very slight win for SMARTY

"While there’s absolutely no difference in 5G coverage between them, you’ve got a better chance of your phone being supported on SMARTY, so they have a very slight edge."

Compare pricing and deals

Download speeds on SMARTY vs iD Mobile

Is either provider faster than the other?

iD Mobile and SMARTY logos with a speedometer

No speed differences between iD Mobile and SMARTY

SMARTY 5G news banner

Read latest 5G news

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Independent speed testers Opensignal measure average speeds on Three at around 25.2 Mbps. Since neither iD nor SMARTY are speed-capped, you’ll get the same speeds on both.

That’s what you’d expect from mid-range home broadband and is enough to stream HD video fairly comfortably. In congested areas you can go as low as 7 Mbps, however, and in built-up areas we got speeds up to 45 Mbps.

Of course, both networks also benefit from the amazingly fast 5G that Three offer. Opensignal and Speedtest by Ookla put Three’s average 5G speeds between 103.9 Mbps and 221.8 Mbps.

With those sorts of speeds you can download HD movies in seconds. It’s great that both networks have full access to 5G despite being budget networks.

Useful link: SMARTY’s 5G guide

Our verdict on data speeds:


"While it is easier to get 5G to work on SMARTY, we’re going under the assumption here that you’ve got it working. In that case there’s no difference between the networks."

Compare pricing and deals

Extra network features on iD Mobile vs SMARTY

Who has better extras to keep you connected?

Gears icon with SMARTY and iD Mobile logos

Both SMARTY and iD now have WiFi calling

SMARTY WiFi calling banner

Check supported phones

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One big problem for networks is in getting their signal for calls indoors. Three’s 3G signal is broadcast on frequencies that aren’t ideal for getting indoors. So they have to offer features to help this.

iD and SMARTY now both support WiFi calling and 4G calling (VoLTE), where it used to be that only iD supported it. You’ll find no difference between the two in terms of how the feature works.

Where you will find a difference is in what phones are supported. Check yours is on iD Mobile's list here and/or SMARTY's list here. We think more phones will work with SMARTY’s WiFi calling than are listed.

WiFi calling lets you use WiFi to make/take calls and send/receive messages if there's poor indoor signal. And 4G calling improves the quality of your call and increases coverage where there’s 4G but no 3G.

Useful link: See all networks with WiFi calling

Neither network offers WiFi hotspots

SMARTY WiFi hotspot FAQ

Read the FAQs

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WiFi hotspot access is a great feature to help users hold onto their data, especially those with smaller data plans. We rate hotspots highly as a great network feature to have.

But, neither of the two networks offer anything of the sort. You don’t even get them on London's Underground network even though Three offer such a scheme. There’s nothing to separate them on here.

But free WiFi is available in most places these days anyway. And if going over your limit is a concern, both networks have some incredibly competitive unlimited plans:

Useful link: SMARTY's hint they may offer it in future

Our verdict on network extras:

No overall winner

"Both have WiFi calling and neither offer hotspots, so there’s really nothing to separate them here."

Compare pricing and deals

Benefits on SMARTY vs iD Mobile

Unused data schemes: iD Mobile vs SMARTY

Which has the best system for data you've not managed to use?

Arrows in circle with SMARTY and iD Mobile logos

A few SMARTY plans pay you back for unused data

SMARTY discount for unused data

How it works

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SMARTY’s initial selling point was that they’d pay you back any data you didn't manage to use, at the same rate as you bought it for - so you'd never waste a penny.

This benefit is still around, but not on all of their plans. Instead they offer special plans that give you money off your next month based on unused data. These are priced higher than their normal plans:

These all pay you back for unused data:

SMARTY will discount your next month £1 per GB of unused data. They even give you back your unused MB as pennies to make sure you’re getting everything back that you would expect.

It’s one of the fairest unused data schemes in the UK, but it’s let down by the fact that they’re at a slightly higher price than their usual plans. Most people would be better off just getting a larger plan.

Useful link: Read our full data discount review

iD Mobile let you keep data you don’t use for a month

iD Mobile data rollover banner

Read full guide

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The tricky thing about monthly data plans is knowing how much you’ll need. If you buy too much you’re wasting money on data you don’t need. Buy too little and you’ll get charged extra for going over.

iD Mobile offer a fairly basic data rollover scheme, where your unused data is saved for next month (though after that it goes away). It’s a fairly common benefit and quite a few other networks now offer it too.

This makes choosing a plan a bit less stressful. Say you know you’ll use 1GB a month at most. You can take a 1GB deal and if you use 800MB one month, you'll have 1.2GB to use next month.

This is best for people with smaller data plans, and it’s nice to have extra data if you ever need it. It also comes on every plan, which is an advantage over SMARTY.

Useful link: Full guide and FAQs on iD's data rollover scheme

Our verdict on unused data:


"SMARTY’s scheme would be better if it applied to more plans. With iD the benefits aren’t as great, but it applies to all plans so every customer will benefit."

Compare pricing and deals

Roaming compared on SMARTY and iD Mobile

Which network is better for going abroad?

A globe with SMARTY and iD Mobile logos

SMARTY’s EU roaming is simple and straight-forward

SMARTY free roaming banner

Full roaming costs

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You can travel to any of these countries within the EU and EEA with SMARTY. You’ll get access to your unlimited minutes and texts and up to 12GB of your data allowance (or your usual allowance if it’s below that).

Their fair usage policy is quite low and the fact you’ll still only get 3G data when roaming abroad means you won’t be able to do the data-heavy activities you would do at home with SMARTY.

It’s a bit annoying to have to turn on roaming manually in your account settings too (here's how you do it). This can become a big problem if you didn’t do this before leaving the UK.

Roaming outside their EU destinations will get very expensive very fast. You’ll have to top up with credit, to pay for your usage at these rates while away. Very few networks give worldwide roaming these days, so this isn’t a death blow.

Useful link: SMARTY's guide to roaming on their network

iD Mobile’s fair usage policy is overly complicated

iD roaming fair usage policy

Read fair usage policy

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iD Mobile and SMARTY’s roaming are the same. You can use your UK allowance with no extra cost and you’ll only get 3G data.

In terms of EU roaming, iD operate an overly complicated fair usage policy dictating how much of your data you can use there, depending on how much your plan costs. Even smaller plans can be restricted.

Beyond the EU, iD do offer a few more countries for roaming. But unless you’re planning on going to Azerbaijan, North Macedonia, Belarus or Kazakhstan this shouldn’t make too much of a difference.

At the very least, roaming just works as it should on iD without having to fiddle around with your account settings. You’ll just have to weigh up ease of use vs ease of working out your fair use limit.

Useful link: All roaming costs on iD Mobile

Our verdict on roaming:

No clear winner

"It’s nice that they both offer roaming schemes when so many networks have cut there’s. But both schemes have weak points: iD's is the fair usage policy, SMARTY is having to manually change settings. It’s up to you which is better."

Compare pricing and deals

Spending caps: iD Mobile vs SMARTY

Which has the best ways of stopping you overspending?

Wallet with SMARTY and iD Mobile logos

iD let you set flexible spending caps

iD spending cap banner

Learn more

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All networks now have to offer you optional caps on your spending to stop you paying more than you want on your mobile bill. But iD offered theirs before this rule came into effect.

Their Capping scheme comes with all their plans (phone contract and SIM only). They let you set a cap anywhere between £0 and £25 at £1 increments. It’s one of the most flexible capping schemes in the UK.

Once you’ve hit your cap, iD will automatically prevent your phone from doing anything that would cost you extra, such as calls to premium numbers. This way you’ll never rack up unexpected bills.

You can keep using your plan’s minutes, texts and data, anything that won’t cost you extra. You can even change your cap whenever it starts to become an inconvenience.

Useful link: Costs for extra usage on iD Mobile

SMARTY plans automatically stop you overspending

SMARTY no more unexpected bills banner

Read why

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SMARTY also stop you from overspending. But they’re different from iD as you’ll pay for everything you’ll use up front. So it’s impossible to accidentally overspend.

When you’re joining up with them you’re paying for your plan with your debit or credit card. If you want to do anything that costs extra you’ll have to top up with credit beforehand (like pay as you go).

So you’ll never accidentally spend more than you want if you never top up. But if you do that you won’t have any credit to use for extras when you need them.

If you want extra you’ll have to manually top up. There’s no option to set a cap and have your usage charged with your bill. You also can’t set a cap on the credit you’ve added.

Useful link: More about billing on SMARTY

Our verdict on spending caps:

Minor win for iD Mobile

"Both networks give you the choice to never pay for extras. But iD make it easier to use extras when you need them without needing to top up."

Compare pricing and deals

Customer service: differences between iD and SMARTY

Which network has better customer service?

Customer service headset with SMARTY and iD Mobile logos

iD Mobile have more ways to contact them

Ofcom complaints data

Read report

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In the government telecoms regulator Ofcom’s report, iD Mobile hit the industry average of 2 complaints per 100,000 customers (SMARTY don't have enough customers to appear in this data).

This shows that iD have really improved their image over the years. We think their excellent iD Mobile account app has definitely played a big part in this, as it lets you manage basically everything.

You can even call up iD if you need help, which is uncommon for small networks to offer. If not, there’s an online chat on their website too, but this will likely take a lot longer than calling up.

There’s many avenues of getting through to someone who can help you. It’s a smooth experience, and you should find your issue gets resolved quickly.

Useful link: All ways to contact iD Mobile

SMARTY only offer online help

SMARTY mobile online chat screenshot

How to get help

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SMARTY are able to cut costs by having the smallest amount of employees as possible, meaning there’s no call centre to help you over the phone.

Instead you’ll have to go online to contact SMARTY, via their online chat function or their social media team. This can be a slow process and can even take over a day to get a response.

We think there’s very little to complain about with SMARTY, but for those less confident with self-serving the lack of over-the-phone help can become frustrating.

It’s night and day when comparing iD and SMARTY on customer service.

Useful link: How to get help on SMARTY

Our verdict on customer service:

A win for iD Mobile

"This is the biggest difference in the two, and it’s an advantage iD very clearly hold over SMARTY."

Compare pricing and deals

Prices and plans compared

Special offers on SMARTY and iD Mobile

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

iD Mobile and SMARTY logos with a special offer tag

SIM only deals on iD Mobile vs SMARTY

Compare latest prices on their SIM only plans below

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iD Mobile's SIM only plans need you to pass a credit check

iD Mobile order process

What gets checked

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All of iD Mobile's pay monthly SIM only plans require you to pass a credit check before you can take one (here's iD's guide to what they're looking into with their checks).

That's because they need to make sure that you will be a reliable bill payer. And that you're not someone who will rack up big bills and then refuse to pay.

This is a standard practice on practically every pay monthly network. For most people this won't be a problem. But if you do have any history of defaulting on bill payments for any service you may find it hard to join.

Their pay as you go SIMs do not have a credit check, because all your usage is paid for up front. Compare all no credit check SIM only plans here.

Useful link: Full guide to iD Mobile's credit checks

SMARTY don't do a credit check

SMARTY no credit checks banner

How billing works

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It's a lot easier to get a SIM only plan from SMARTY. As long as you've got a UK debit or credit card, you can join. There's no credit check to pass.

Instead you register a card and your monthly plan is charged onto that. If you want to do anything that would cost extra, you have to pre-pay for credit or an add-on.

This system means that SMARTY can never get into the situation where someone racks up a bill and then refuses to pay.

The result of that is that they don't need to run a credit check on new customers. So if you've been declined before, SMARTY may be a better choice than iD Mobile.

Useful link: SMARTY's guide to billing on their network

Our verdict on SIM only plans:

Depends on current offers

"We think most people looking to join SMARTY and iD Mobile are just looking for the best value per minute, text and GB data. That varies month-to-month, so it's hard to pick an overall winner."

Compare pricing and deals

Phone contracts on iD Mobile and SMARTY

Do they both offer pay monthly handset deals?

iD Mobile and SMARTY logos with a phone

Phone options


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Only iD Mobile has phone contracts

Screenshot of iD Mobile phone range

Compare phone contracts

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SMARTY have been set up as a low cost SIM only plan provider and so don't do phone contracts at all. And we doubt they ever will. So out of the two, iD Mobile are the only choice.

Thanks to being owned by Carphone Warehouse, iD have a massive range of phones, including the Apple and Samsung models you'd expect. Their general pricing is lower than average.

iD's phone contracts are on straightforward 24-month terms - there's no complicated financing arrangements, just a monthly cost for your minutes, texts, data and the phone itself.

If you want a simple, low-priced phone deal with all the benefits we've described in all the other sections of this page, you could do worse than consider iD Mobile.

Useful link: See iD's range of phone contracts

Our verdict on phone contracts:

Automatic win for iD

"If you want a contract for a phone, iD are the only choice out of the two - so they win by default."

Compare pricing and deals

More iD Mobile guides

More SMARTY guides

More mobile network reviews