SMARTY review 2024: faster speeds & better 4G/5G coverage

Coverage on SMARTY has improved over the years

SMARTY were set up as a sub-brand of Three, so they share their parent company’s 4G/5G network. You get identical coverage between the two. We’ve found no disadvantage for being on SMARTY vs Three.

Rural 4G data signal (see 5G here) has been a weakness in the past for SMARTY. But during our recent tests we’ve been pleasantly surprised to see how much their signal has improved, thanks to Three’s huge network investments.

More about our real life SMARTY coverage tests…

It wouldn’t be possible to test signal all over the country. We were able to check signal in various locations to see if their coverage map is accurate to the signal you get in real life and is the same as on Three.

We loaded a Three SIM in one and a SMARTY SIM into two separate but identical test phones and went out to test coverage.

Everywhere we checked we got essentially identical signal between the two providers. While it fluctuated, there was no clear advantage on either. We got 4G and 5G in the same locations on Three and SMARTY.

What we found lined up well with what their coverage map showed. And they’re also totally honest with the location of blackspots which is good considering there are a fair few out in the countryside.

If you’ve previously ruled out joining a network on Three, now’s the time to re-check their coverage in your area. There are still some holes in coverage, but the overall picture has improved massively.

It’s a similar story for calls. SMARTY’s national coverage is great, but indoor blackspots can be a problem if your phone doesn’t support 4G calls. And you’re still more likely to lose call signal than on the other networks.

Useful link: Check SMARTY coverage near you now

4G data speeds are a strength on SMARTY

We have never found any built-in speed differences when testing out a Three vs a SMARTY SIM side-by-side. So, you get all the benefits of Three’s £2 billion network investment on SMARTY.

These network improvements have had a noticeable effect when looking at their typical 4G speed results, now at 35.4 Mbps according to independent network testers Opensignal’s report (see 5G speeds here).

More about our SMARTY data speed tests...

Just like we can’t test every inch of the UK for coverage, we can’t do speed tests everywhere. But, we checked speeds on SMARTY vs Three directly in the same urban and rural locations.

There were no in-built speed differences between the two. While speeds weren’t always identical, that’s what you’d expect when testing two SIMs on the same network directly against each other.

In the suburbs we got our lowest result of 7 Mbps, while we got as high as 40 Mbps over 4G in a rural area where there was no signal congestion. In the city centre we got speeds as high as 70 Mbps.

SMARTY also get access to good speeds over 3G. Speeds went up to 12 Mbps over 3G signal, which is faster than their slowest 4G speeds. But speeds over 3G more often sat around 4 Mbps.

That’s similar to what you’d get over mid-range fibre home broadband, letting you stream HD videos smoothly. Their result puts SMARTY in joint second place (alongside Three) for 4G data speeds across all UK networks.

In our tests we tended to stay around the 25 - 30 Mbps mark more consistently on SMARTY than on other networks. Speeds can be faster or slower than that, but rarely do you go hugely above or below that.

Useful link: SMARTY's promise not to slow you down

5G speeds can be genuinely impressive

Getting access to Three’s 5G network is one of the best parts of joining SMARTY. Speedtest and Opensignal’s speed results show that they’re way ahead of any other network for 5G speeds.

Both testers’ latest reports show typical 5G speeds between 205.5 Mbps - 246.89 Mbps on SMARTY’s host network. And peak speeds can get up to 625.87 Mbps, which is over twice as fast as the next fastest network.

Best current SMARTY SIM only plans with 5G

Like on all networks, our real-life testing of SMARTY’s 5G produces varying results. Sometimes, you’ll be on 5G and see absolutely no advantage over 4G. Other times, the 5G speed advantage is staggering.

You’ll get 5G in 484+ UK towns and cities on SMARTY. While they don’t have the largest number of locations, you’ve still got a good chance of getting 5G near you. And they tend to cover their locations very well.

Useful link: Our rankings of the best 5G networks

WiFi calling works well in our experience

You may be more likely to run into indoor calling blackspots on SMARTY due to their 3G being broadcast on high-range frequencies that aren’t good at getting into buildings. But SMARTY provide a solution:

They now provide both WiFi calling and 4G calling on every plan. These features let your phone connect to calls and texts over WiFi or 4G signal where regular 3G call signal is weak.

We did some tests and found that SMARTY’s WiFi calling works exactly the same as Three’s. But some users have said it didn’t work on their phone, so make sure yours is on SMARTY’s list of supported devices here.

The test phone we used wasn’t listed but worked just fine. We think WiFi calling is basically a must-have on mobile networks nowadays (see all that do have it here), so it’s fantastic that SMARTY offer it.

Useful link: SMARTY's WiFi calling help section

Free WiFi hotspots are only other extra network feature

Here we’ll go over the other network features that SMARTY offer. They offer an identical scheme to Three’s WiFi hotspot benefit, letting you stay connected to WiFi hotspots on the Underground at no added cost.

You can tether other devices to your data signal on SMARTY (essentially turning your phone into a personal hotspot). And SMARTY don’t limit how much of your allowance you can use for tethering in the UK.

SMARTY also offer call forwarding which lets you divert incoming calls to a different phone number if you want to leave one line free from calls. You can read their handy guide to setting it up here.

But visual voicemail is not supported on SMARTY, which usually lets you sort through your voicemails one by one. And you can’t take an eSIM on SMARTY either, which is something you can do on Three.

Useful link: SMARTY's network feature FAQs

EU roaming is a welcome benefit people will enjoy

Lots of other UK providers have removed inclusive EU roaming from their deals. But SMARTY still let you use data and your unlimited calls and texts to UK and EU numbers in these 42 EU destinations at no added cost.

You can use up to 12GB of your allowance each month while abroad. If you hit that limit you’ll have to pay for extra data. Thankfully, SMARTY’s extra data add-ons are the cheapest of all networks.

How we found SMARTY's roaming...

When we first tested SMARTY’s roaming, we didn’t know we had to turn it on manually beforehand. This was a bit of a headache, so make sure to follow SMARTY’s guide to turning on roaming here.

Our SMARTY SIM connected right away to 4G while abroad, but you can’t connect to 5G abroad. We don’t see it as a huge loss, but you won’t be able to get the fastest speeds possible while roaming.

We got 4G almost everywhere while there which let us read maps, online review and access social media with decent speeds. SMARTY’s roaming is excellent overall, just remember to turn it on before leaving.

There are no inclusive roaming destinations beyond the EU, but we wouldn’t expect that from them. If you’re going further afield you’ll pay at these rates, which can get very expensive (£100 per GB in the USA!).

It’s important to remember you have to turn on roaming manually before taking your SMARTY SIM abroad. Use their guide here to do it. It’s an annoying downside to an overall good EU roaming scheme.

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

Their group plans are our best choice for family discounts

If you’re looking to get your kids or other family members onto their own SIM only plans, SMARTY are a brilliant option. They have our favourite family plan scheme of all networks thanks to the value they give you.

With SMARTY’s group plans you can add up to 7 extra SIMs onto your existing SMARTY account, with each added SIM getting 10% off the original cost. That’s 10% off already great value deals.

Each user can choose their own plan and you can add new plans whenever. And there’s the added convenience of managing your SIMs in one place, making it easier to set parental controls and manage extra spending.

The only real drawback is that the billing date for each plan is on the same day you took it out when it’s more convenient to have your plans billed on the same date. But SMARTY’s family plans are excellent overall.

Useful link: Full details on SMARTY's Group Plans

There are a few other handy benefits on SMARTY as well

There are a few other benefits of joining SMARTY as well. First of all, they won’t up the cost of your plan if you stay on it. Many other networks hike up your bill with RPI (inflation), but SMARTY don’t do this.

SMARTY’s deals naturally have spending caps on them. If you want to use any features that would cost extra, you must first to top up with credit or buy an add-on. If you don’t, you can’t accidentally overspend.

And you don’t need to pass a credit check to join SMARTY since you pay for your plan up front instead of joining on a contract. This also leaves you free to leave your plan at any point by not renewing your plan.

A few of SMARTY’s plans have a special data discount benefit, giving you back the value of your unused data as a discount off your next month’s deal. But these are worse value than SMARTY’s other plans anyway.

Useful link: Why are SMARTY so cheap?

✔ Key facts about SMARTY's SIM only plans

SMARTY are solely a SIM only provider. There’s no way to join them on a phone deal directly. They have promised to bring some in, but that was in 2019. And there’s no sign that they’ll introduce these any time soon.

But, as an existing SMARTY SIM only customer you can get £50 off the cost of a refurbished phone via a third party called reboxed. But these aren’t on contracts, you have to pay the whole cost of the phone outright.

If you still want to join a phone deal while getting access to Three’s network, iD’s range of good value phone deals are a good choice or you can join Three directly.

You can compare phone deals on all networks using our comparison tool here. This lets you find the best deal on the phone model you want. Follow the link below to try it out:

Useful link: Use our phone contract comparison tool

There’s no traditional Pay As You Go on SMARTY either

There are only a few UK networks that still let you top up with credit and pay as you go per min, text and MB of data. SMARTY aren’t one of them. You have to renew your plan each month to keep your SIM active.

If you only use your phone for a few calls or texts now and again, SMARTY aren’t a great choice. Instead, we’d look at 1pMobile who offer rates of 1p per min, text and MB data (read full details here).

1p per minute + 1p per text +  1p per MB data =  £0 a month (0‑month contract)
See full deal

Three charge 35p per min, 15p per text and 10p per MB, so they’re really not a good choice for paying as you go. But if you want to stay on Three’s network while paying as you go, there are no better choices.

But if you’re a frequent phone user, then you might find you’d spend less on a SMARTY SIM only deal than constantly topping up and paying for your usage. But infrequent users will be better on these networks.

Useful link: Read our 1p Mobile review