Comparison of Unlimited Mobile Data SIMs from UK Operators

Over the past few months all of the three major UK mobile network operators – EE (BT), Vodafone and O2 – have joined Three UK in offering 4G or 5G pay monthly mobile data (mobile broadband) plans with “unlimited” allowances. We take a quick look at what you can get (SIM-Only) for your money and some of the caveats.

Until recently if you wanted “unlimited data” (aka – “all-you-can-eat“) then Three UK, which offers such a feature on both their mobile SIM and specialised HomeFi / Home Broadband plans, was one of the only games in town. Three’s MVNO sibling Smarty also offers such a plan.

Admittedly Virgin Media (Virgin Mobile – EE MVNO) also offers an unlimited data plan, although this is only available to their existing fixed broadband or TV customers. Likewise giffgaff (O2 MVNO) has an “always-on” goodybag but we don’t consider this to be truly “unlimited” because of a hefty restriction (i.e. after 40GB of data used you’ll experience a reduced data speed of 384kbps from 8am to Midnight).

Similarly Lycamobile has a “forever data” plan but, much like giffgaff, this isn’t considered to be truly “unlimited” either because after consuming 9GB of data it will reduce your mobile data speed to just 128Kbps, which is unbearably slow and many modern internet services simply won’t work properly, or even at all, at that speed.

However the race to rollout and up-sell 5G technology to consumers has changed all that. The first to jump was Vodafone in July (here) and, with two major operators now doing “unlimited“, rival EE soon decided to join the party (here). Shortly after them O2 (Telefonica) announced that they too would be going unlimited (here), although at this point it’s not like they had much of an alternative.

Unlimited Mobile Data Comparison – SIM Only

The quick comparison below only focuses upon pay monthly SIM Only plans and doesn’t include dedicated mobile broadband services, which is because not all operators have an unlimited option for their mobile broadband plans. In any case there’s often nothing much to stop you putting such a SIM into a 4G or 5G router – they all support Tethering below (but any calls / texts may go to waste).

In addition, we’ve only focused upon the cheapest unlimited data plans available from each operator and as a result have had to include Vodafone three times because their unlimited options are tiered by speed (most of the others don’t cap by speed, so it’s necessary to show the impact of Voda’s approach). Likewise we have a second entry for EE since their 5G unlimited plan costs extra.

All of the plans below come with the usual assortment of unlimited calls and texts. 3G support is assumed and O2 has yet to launch their 5G service.

Obviously the above prices don’t consider some of the value-added extras that different operators may include, such as free access to WiFi hotspots (e.g. O2), extended roaming access (e.g. Vodafone), security features, discounts on other services or access to premium content etc.

Lastly we’ll touch on the issue of soft data caps and usage restrictions. Generally mobile operators don’t allow “commercial use” on unlimited data plans, which means that doing thing likes hosting web servers (already tedious anyway given the use of CGNAT) or consistently gobbling masses of data for several consecutive months could get you moved to a more expensive business plan.

In terms of penalties for exceeding a soft cap, some operators may contact you if you’re consistently gobbling well over the stated level but they often don’t seem to take any further action, although the threat is there in the T&Cs for some of the operators. See the examples below, which also mention the data caps for EU roaming.

Extract from Terms & Conditions (Unlimited Plans)

O2

“Fair use policy applies, personal and non-commercial usage only. If you regularly use 650GB of data per month or tether 12 or more devices we may consider this to be none permitted use and have the right to move you to a more suitable plan. EU roaming capped at 20GB per month, chargeable at 0.4p per MB afterwards.”

Vodafone

“No matter what Unlimited plan you choose, you’ll have unlimited data to use in the UK. Our plans come with different maximum mobile data speeds, to match how you use your data. Our Unlimited Lite plan has a maximum mobile data speeds of 2Mbps, Unlimited has a maximum speed of 10 Mbps and our Unlimited Max plans let you access our 5G network at full speed.

Roaming data on all Unlimited data plans is capped at 25GB per month in inclusive roaming & £6/day roaming destinations.”

Three UK

“Certain usage, for example, for commercial purposes, isn’t allowed under our Terms for Three Services, so we’ve set a usage cap at 1,000 GB, in order to help identify non-permitted use.

In addition to these Unlimited UK allowances, if you are a Pay Monthly customer you can use up to 15,360 data units (which converts into 15GB of data as 1 data unit converts automatically on use into 1MB of data) each month when in a Go Roam in Europe destination.”

EE

“Uncapped and Unlimited data – 15GB fair use policy applies outside UK. Personal, non-commercial use only. If you regularly tether 12 or more devices, we will consider this non-personal use and have the right to move you to a more suitable plan. We will consider usage above 1000GB/month to be commercial use and have the right to move you to a business plan.”

Some readers have also queried about unlimited data on PAYG (Pay As You Go) plans, which tend to be a bit more complicated. Three UK does an unlimited data add-on (30 day expiry) on PAYG for £35 and Smarty’s 1 month plan for £25 (above) is very close to being the same thing. Most other operators do not yet have unlimited data for PAYG plans.