SMARTY vs Three: all differences between the two networks

✔ Coverage is completely identical on SMARTY and Three

SMARTY are a sub-brand of Three, one of the main four UK networks. As such they use Three’s network to provide call signal (3G) and data signal (3G/4G/5G).

Three have massively improved their 4G coverage to the point that they now have one of the most widespread 4G networks in the UK. SMARTY get full access to this with no differences vs being on Three.

You also get full 5G access on SMARTY. That means you’ll get 5G in the same long list of 580+ locations, with generally great coverage within these locations. There’s no difference being on SMARTY for this.

Best 5G SIM only deals on SMARTY and Three

Three have almost completely phased out 3G to expand their 4G even further. They never had older 2G technology. So for calls and texts, you’ll need a phone that supports 4G calling on either.

Useful link:
Three's latest network developments

✔ 5G/4G data speeds are exactly the same on both

We tested speeds on our SMARTY SIM vs our Three SIM and found no evidence of a built-in speed cap or any difference in signal strength. The speeds you get on Three are the speeds you get on SMARTY.

In the city centre, we got 4G downloads over 70 Mbps on both, while speeds slowed down to 5 Mbps in the countryside. More often we sat around 30 Mbps, which lines up with Opensignal’s result of 38 Mbps.

Opensignal got typical 5G speeds of 208.9 Mbps while Speedtest got speeds of 260.22 Mbps. And peak speeds can get up to a blistering 680 Mbps. We experienced these kind of results on SMARTY too.

Best 5G SIM only plans on Three and SMARTY

Again, there’s no disadvantage of being on SMARTY vs Three for data speeds. It’s brilliant that you get access to the fastest 5G speeds with great 4G speeds on top of that on a budget network like SMARTY.

Useful link:
SMARTY's policy on network throttling

✔ Three and SMARTY have similar WiFi/4G calling

With Three removing 3G call signal, it’s great that both offer WiFi and 4G calling so you can connect to calls and texts over WiFi/4G instead. And SMARTY’s WiFi calling seems mostly the same as Three’s.

They publish this list of supported devices. Our own testing found even models not listed there can still work. And you can transfer calls from WiFi to 4G without them dropping on SMARTY and Three.

Best SIMs on SMARTY and Three

SMARTY also get access to Three’s network of free WiFi hotspots on the Underground. There’s no difference in the amount of hotspots you can use and you get full access to it on all of SMARTY’s plans.

But one of the advantages of Three being a bigger network is that they can offer network features like eSIMs and visual voicemail that SMARTY don’t get access to. These are pretty big upsides to being on Three.

Useful link:
All UK mobile networks with WiFi calling

✔ Inclusive EU roaming is much better on SMARTY

All SMARTY plans include EU roaming as standard, at no extra cost. While on Three, most plans don't include it. You will have to take a more-premium plan to be able to roam in the EU and beyond.

You can use up to 12GB of your regular data allowance there on SMARTY. That will be easily enough for most people. But it’s worth knowing you will have to follow these instructions to set up roaming.

Best EU roaming plans currently on Three and SMARTY

Roaming on Three is a little more complicated. If you take a Value or Complete plan, you’ll get a set number of days you can roam in the EU and these worldwide countries too. On SMARTY all non-EU roaming costs extra.

So a lot of your choice will depend on how often you travel and where you’re going.

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

✔ Family plan discounts and more on SMARTY

If you’ve got family or close friends that need a SIM only plan, SMARTY give you a handy 10% discount on any extra plan you add to your account. That gives you extra value on top of SMARTY’s already low prices.

You can get this discount on up to 7 added plans on your account. And this lets you manage all your plans in one place, so you can easily stop your kids from racking up extra data costs or accessing adult content.

Best current SIM only plans on SMARTY

SMARTY also offer all their plans on flexible 1-month deals that you can change or leave altogether each month. That’s great if you’re paying for more data than you need or want to be free to leave when you want.

And you don’t need to pass a credit check to join any of SMARTY’s plans like you do on Three. That makes SMARTY a brilliant option if you’ve been rejected for a credit check by Three.

Useful link: Read more about SMARTY’s family plans

✔ Better customer service and more on Three

All Three customers get access to their rewards app Three+ that gets you special offers on high street shopping and restaurants and even some freebies. And you can get presale tickets to Three hosted events.

You can get a lot more out of it now than when they first brought it out. Have a look at the kinds of offers you can get on Three’s website here to see if it’s something you’d get the most out of.

Three also let you call them up to get help, while SMARTY’s customer service is online only. That can be a deal breaker if you want the option to phone them if you run into any issues with your plan.

Best current SIM only deals on Three

Also, Three offer some extra benefits on their higher-end Premium and Plus plans, such as an extended warranty on your phone or a subscription to Paramount+ (see all benefits in our guide here).

Useful link:
Our guide to the Three+ app