Most UK mobile networks offer what they advertise as ‘unlimited data’ on their top plans, but that doesn’t always mean that you truly have access to an unlimited amount of data, as there are often fair usage limits in place.
To further complicate matters, these fair usage limits – and what form they take – differ from network to network, so in reality one network’s unlimited data plan can look quite different to another’s.
Below then, you’ll find more details on what’s actually meant by ‘unlimited data,’ what sorts of fair usage restrictions you might run into, and then the specific policies of each UK network that offers unlimited data.
What do we mean by ‘unlimited data’?
Unlimited data should logically mean an endless amount of data to use for web browsing, streaming, downloading, and anything else on your phone, but in reality it often more means simply a very high amount of data, after which depending on the network’s policy your speeds might be throttled or your data might be cut off.
This very high amount of data is often in the region of 600GB, which is far more than most people should need in a month, but it’s still not unlimited.
And we’re only talking about the UK here – with rare exceptions, any listed data limit only applies for UK use, with almost all networks having a separate fair use data limit when roaming.
What sorts of fair usage restrictions are there?
The most common fair usage restriction is a maximum amount of data that the network is happy for you to use each month, and where this applies it’s typically in the region of 600GB, though not always.
Though it can be a bit more complicated than that, as the terms might say for example that you shouldn’t exceed this figure twice in a six month period.
Another fair usage restriction you might come across relates to tethering, with some networks stating a maximum number of devices that you should share your data connection with at any one time.
Less common is speed restrictions, either speed limits that always apply, or ones that kick in after you use a certain amount of data.
And then there’s roaming, where the fair use limit is usually far less than unlimited.
Finally, almost every network states that your data should be used for personal, non-commercial purposes.
Which networks offer truly unlimited data in the UK and abroad?
| Network |
Fair use limits |
| Sky Mobile |
Don't exceed reasonable usage |
| Tesco Mobile |
Use more in the UK than abroad |
The only UK networks that we’d say truly allow unlimited data to be used both in the UK and abroad are Tesco Mobile and Sky Mobile.
Tesco Mobile has no real fair usage terms in the UK, and when roaming its only real stipulation at the time of writing is that you should spend more time in the UK than abroad – so there’s not a cap on data use.
That said, like most networks Tesco Mobile prohibits commercial use, and also notes that your SIM card must only be used in a phone or tablet.
As for Sky Mobile, that states that when both in the UK and abroad you shouldn’t use more than is “reasonably expected of a reasonable person,” so there may be more restrictions there than on Tesco, but there are no specific caps. Note however that Sky Mobile does charge for roaming.
Which networks offer truly unlimited data in the UK but not abroad?
| Network |
Roaming limits |
| iD Mobile |
30GB |
| Lebara |
30GB |
| Smarty |
12GB |
| Spusu |
15GB |
| Talkmobile |
5GB |
| Three |
12GB |
| VOXI |
20GB |
Aside from the standard caveat that you shouldn’t use your data allowance commercially or for any illegal purposes, Three, iD Mobile, Lebara, Smarty, Spusu, Talkmobile, and VOXI all allow you to truly use an unlimited amount of data in the UK, with no significant fair usage limits.
As for roaming, on iD Mobile and Lebara the limit is 30GB, on VOXI it’s 20GB, on Spusu it’s 15GB, on Three and Smarty it’s 12GB, and on Talkmobile it’s just 5GB.
What are the other networks’ policies?
| Network |
Fair use limits |
Roaming limits |
| Asda Mobile |
Speed caps |
5GB |
| CMLink |
650GB, 12 tethered devices |
10GB |
| EE |
600GB, 12 tethered devices |
50GB |
| Giffgaff |
650GB, 12 tethered devices |
5GB |
| Honest Mobile |
Speeds may drop at 650GB |
20GB |
| Lyca Mobile |
450GB on some plans |
30 or 35GB |
| O2 |
650GB, 12 tethered devices |
25GB |
| Vodafone |
600GB, speed caps on some plans |
25GB |
EE, O2, Vodafone, Asda Mobile, CMLink, Giffgaff, Honest Mobile, and Lyca Mobile all offer unlimited data plans too, but with more limitations.
Note that where we mention a fair use data limit in the UK, in most cases it’s not a hard limit, with networks using language like ‘around’ that much data, or saying if you use that much twice in a six month period, they ‘may’ investigate your usage. So if you just the amounts listed once, you might be fine, but equally there’s a chance slightly lower usage could catch the network’s attention.
In any case, on EE, there’s a fair usage limit of 600GB per month in the UK and 50GB when roaming, and you shouldn’t regularly tether 12 or more devices, while on O2 you’re limited to 650GB per month in the UK and 25GB when roaming, and you shouldn’t regularly tether 12 or more devices. Vodafone meanwhile has a 600GB fair use limit in the UK, and 25GB abroad, as well as speed caps on some plans.
Asda Mobile has no UK limit but does cap your speeds, with the maximum (depending on the unlimited data plan you choose) being 150Mbps. It also has a low 5GB roaming limit. As for CMLink, that has a 650GB limit in the UK and a 10GB limit while roaming, as well as stating that you shouldn’t regularly tether 12 or more devices.
Giffgaff has a 5GB roaming limit, along with a 650GB limit in the UK and a stipulation that you shouldn’t tether 12 or more devices, while Honest Mobile will drop your speeds to 3G levels if you use more than 650GB a month in the UK, and has a 20GB roaming limit, and Lyca Mobile has either a 30GB or 35GB roaming limit (depending on your plan) and some plans list a 450GB UK fair usage limit in the UK, though others don’t.
