Mozillion vs spusu: what's the same, what's different?

✔ Coverage is exactly the same between them

Both spusu and Mozillion piggyback off EE’s excellent network for coverage, so you get identical 4G/5G data signal and 2G call signal on both. We’ve physically tested both SIMs against EE and found no differences.

It means they both have the most widespread 4G data signal of all UK networks. You get quality 4G in some surprisingly rural areas and basically everywhere in urban areas on both, including on band 20.

You’ll also get 5G data in this long list of 1000+ UK towns and cities on both, with excellent coverage within these locations. Again, 5G signal is completely identical on both providers.

Best 5G SIM only deals currently on Mozillion and spusu

And you get identical 2G call signal on both. There is no 3G any more. Even 2G is slowly being phased out. It’s worth noting that some spusu customers have complained about not being able to receive OTP texts.

Useful link: Check Mozillion’s signal map | Check spusu’s signal map

✔ Data speeds are identical between the two providers

As well as sharing identical coverage, both providers offer the same data speeds as being on EE directly. There are no speed caps or built in limits on any of their plans. So what does that look like in real life?

We got 4G speeds as high as 130+ Mbps on their hosts in the city centre, while speeds went down to 5 Mbps in the countryside. Most often speeds sat around 30-40 Mbps which matches Opensignal’s result of 45.9 Mbps.

For 5G it’s the same story. Both get full access to their hosts’ typical 5G speeds of 96.8 Mbps according to Opensignal or 114.39 according to Speedtest with healthy peaks of 324.42 Mbps.

Best current 5G SIM only plans on spusu and Mozillion

As there are no differences in speeds between the two providers, this isn’t something we can compare them on. But speeds are a strength on both, particularly for 4G.

Useful link: Read what spusu say about their data speeds

✔ WiFi/4G calling is a bit better on Mozillion

WiFi calling and 4G calling are features that let you connect to calls using WiFi and 4G signal instead of conventional 2G/3G. It’s crucial for networks to have a good scheme as call signal is being removed.

So it’s good that both have it. Mozillion have taken theirs off the shelf from EE, which means they support more devices. And you can switch from a WiFi call to a 4G call without it dropping. On spusu, this does not work.

Best SIM only plans with WiFi calling on Mozillion and spusu

Both networks do include call forwarding, letting you redirect incoming calls to another number. And neither of them offer visual voicemail. It’s mostly just the big networks that offer this anyway.

Finally, both providers let you join on an eSIM. We’d say spusu’s scheme is slicker as there is a bit of a delay when joining Mozillion on an eSIM. But it’s still great that both give you the option.

Useful link: Read Mozillion’s guide to their WiFi calling

✔ EU roaming is a bit better on Mozillion than spusu

Mozillion and spusu both let you use your plan in the EU at no added cost. See spusu’s roaming page here for a full list of destinations and Mozillion’s here. Minutes and texts are unlimited in the EU on both.

The main difference to get your head round is their fair usage policies for using data in the EU. On Mozillion, you’ll be able to use 25% of your regular data allowance there. Or 25GB if you’re on their unlimited data plan.

On spusu, the system isn’t so uniform. Each plan has its own separate cap, up to a maximum of 10GB or 15GB on their unlimited data plan.

Compare unlimited plans on spusu vs Mozillion

Going outside the EU is a big difference. It’s literally not possible on Mozillion. It’s not that it just costs extra, it’s literally your SIM won’t work. On spusu, it’s possible but you’ll pay at some pretty expensive rates.

Useful link: Read Mozillion’s guide to their EU roaming

✔ spusu have better customer service and other benefits

spusu include inclusive minutes to EU numbers on all their plans. That can save you quite a bit if you call abroad often and some plans even include unlimited EU mins which can be very handy.

We also like that you can manage your plan using their app, letting you easily switch plans or change your spending cap. Mozillion don’t let you do this online at all, so spusu are a lot more convenient for this.

spusu’s best current SIM only deals

On top of that, spusu have much better customer service. Their agents are clearly based in the UK and are knowledgeable. Mozillion’s are also in the UK but not quite as diligent. You can also WhatsApp or email spusu.

We’ve found they tend to get back to you quite quickly and have always been reliable. And finally, spusu promise not to increase your plan’s price until 2026.

Useful link: How to get help with spusu

✔ Mozillion offer nice longer contracts but not much else

Mozillion offer a range of longer 12 and 24-month contracts that are better value per month than their 1-month deals and can beat spusu on price as well.

Mozillion’s best SIM only contracts

And you don’t have to pass a credit check to join these, unlike on many other networks. So basically anyone can join these as long as they can afford the price of the plan.

But that’s really where the benefits end. Mozillion are very much a low-frills network and don’t offer much that spusu don’t also offer.

Useful link: See Mozillion’s full range of SIM only contracts