Unlimited data SIM only deals in July 2024: the best offers on EE, Three, Vodafone and more

There was a time where unlimited data SIM plans were a luxury, requiring you to fork out a mini-fortune each month to not have to worry about your usage. Those times are now long gone with a sea of networks bidding for the lowest price on unlimited everything.

While you can still easily end up spending a lot, the best unlimited data SIM only deals keep costs low while still removing your usage limits, and if you're lucky, they'll even throw in a few added benefits.

For years now, the Three network has fought off competition to offer the best value limitless SIM, but the margins are always shrinking with other networks closing the gap.

Of course, there are cheaper SIM only deals out there if you're not actually a big data user, but there is a certain bliss in having the restrictions removed for a few extra quid if you are nearing your limits each month.

On top of that, the ability to tether other devices to your unlimited data plan means you can use your tablets, computers or other devices on the go without draining your phone's data.

Our top pick is (and has been for a while) Three's £16 a month plan. It is one of the lowest prices around, especially if you are only looking at one of the major networks, and it only ties you in for a year if you feel like changing.

If a full year of commitment isn't for you, iD Mobile offers unlimited data on a 1-month rolling plan for only £18 a month

Not sure what you are looking for? Read on to find out more about the world of unlimited data SIM only deals.

The best unlimited data SIM plan

Three | 12-month contract| Unlimited data | 5G | Unlimited calls and texts | £16 per month

Three | 12-month contract| Unlimited data | 5G | Unlimited calls and texts | £16 per month
Three has thought a good battle when it comes to unlimited data SIM only deals. For years now, the network has offered the best overall value unlimited plan at just £16 a month. It ties you in for a year which, while not the shortest plan, is much more flexible than the 18 or 24 month alternatives that are out there.

Choosing the right unlimited data SIM:


(Image credit: William_Potter)

Do I actually need unlimited data?

For the average person, unlimited data is going to be an excess. With publicly available Wi-Fi in just about every shop, cafe and business, finding yourself without internet is becoming rarer and rarer.

The best idea is to take a look at your current data usage. This can give you an indication if you're in need of an unlimited data plan. Usually, it is those having to tether lots of devices on the go, mobile gamers or fans of HD streaming that will most benefit.

The other factor to consider is if you would simply like the safety that unlimited data offers. Not having to keep an eye on your data cap is a nice benefit of these tariffs.

How long will my contract be?

SIM contracts tend to come in one of a couple of options: 1-month rolling, 12 months, 18 or 24.

There are a host of networks that will only offer 1-month rolling plans. These include Voxi, Smarty, GiffGaff and Lebara. Alternatively, the likes of Three and iD Mobile can offer a rolling plan at a higher cost.

EE, Vodafone, O2 and a few other networks find their best price points in 12 months or higher. Get to the 24 month mark and your price will fall in return for a longer commitment.

Which network offer unlimited data and which is best?

Most of the main networks now offer unlimited data. This includes Three, EE, Vodafone, O2, Virgin, iD Mobile, Voxi and more. However, not all networks have an unlimited plan and some have catches to them.

Vodafone has unlimited data but to get a good price, you'll have to have imposed speed restrictions or commit to a two-year contract. EE too has unlimited data but charges some big prices to get it.

The good news is that all of the big players now include 5G as standard. So if your handset is 5G-compatible, you'll automatically get the best the fastest speeds where available.

Three arguably has the best options for unlimited data. It's one of the four main networks, it's 5G-enabled and almost always has one of the lowest prices around.

Swipe to scroll horizontally
Unlimited data SIMs by networks:
Header Cell - Column 0 EEO2VodafoneThreeiD MobileGiffgaffVirgin MobileTesco MobileVoxiSmarty
5G enabled?YesYesYesYesYesYesYesYesYesYes
Pros:UK's fastest 5G speedsGreat freebies includedVeryMe reward schemeBest value tariffsCheap1-month rolling contractsAffordable pricesClubcard discounts1-month rolling contractVery cheap
Cons:ExpensiveExpensiveSpeed restrictions1-month terms more expensivePiggybacked coverageNo major incentiveNo major incentiveNo unlimited calls and textsCheaper prices availableNo added benefits

Can I get an unlimited data only SIM?

Unfortunately, unlimited data only SIMs aren't exactly common place. While you can get a SIM with a lot less data for your tablet or another internet connected device, unlimited data won't be available.

There is a pretty simple workaround though. As we mentioned above, most of these SIM plans allow for tethering. That means you can simply connect your tablet to your phone's SIM plan and voila - you're all sorted.

Of course, the other option is to find a data only SIM deal with less data. 

Switching to an unlimited data SIM:

SIM only deals

(Image credit: ra-photos)

How to switch to unlimited data SIM only deals:

While it used to be a tricky procedure, changing phone plans is actually extremely simple nowadays.

Firstly, you need to know you're eligible to switch plans. If your contract still has a few months until it ends, you are likely to be charged for the remaining time meaning it is usually best to fully finish your contract first.

Switching and keeping your number:

Once you know when your contract is finishing and you've got your new deal, you need to decide if you want to keep your number. If so, you can request a PAC code (Porting Authorisation Code) from your old network. This can be done via the phone or through a text.

Then you simply get in touch with your new provider and give them your new code. Each phone number or text code to get a PAC code is different for each network - all of them list this information clearly on their websites.

Switching with a new number:

Don't want to keep your number - it's even easier! Simply get in contact with your new provider and tell them you want a new number and tell your old network your ending your contract.

This can also be done via a text to switch service. Simply text STAC to 75075.

Is my phone locked to a network?

If you're looking to get a new SIM plan for an old phone - whether its yours or one you bought secondhand - you could find that it is locked to a network. This is where a phone has had a SIM in it and now can only use that network.

While that sounds permanent, it's actually easily fixed. First, try putting a SIM card from another provider into your phone. Make a call and if you can't then its locked. You can also get in contact with your network to find out if its still locked.

How to unlock a smartphone:
Unlocking a smartphone is either a breeze or a bit more complicated depending on the network its locked to:

  • EE Once six months have gone by on your contract, you can call EE on 0800 956 6000 and pay them £8.99 to unlock your phone. It says it will take around 10 days to complete. PAYG phones can be unlocked for free. Both iPhones and Google devices unlock for free after a certain time with EE.
  • O2 Whether you have an iPhone or Android device, pay as you go or on a contract, O2 can unlock it for free. You simply need to log into the O2 app, select unlock my phone and you're good to go.
  • Three Fear not, all phones on Three are unlocked as standard. Shove whatever SIM you like in there, it will work a treat.
  • Vodafone The red network doesn't quite get the same marks as Three, as your phone will be locked to them on arrival. But they have made unlocking handsets absolutely free within 10 days of your request.

What SIM card size do I need?

SIM cards these days fall into three sizes and these are: Standard, Micro and Nano, descending in size. If you're ordering your SIM only you'll likely find it arrives in a credit card sized piece of plastic out of which can you pop your microchip SIM.

It is most likely that you will receive a Combi SIM, no matter which provider you choose. The Combi SIM contains all three sizes, and you push out the one that fits your phone. This is ideal as you don't need to know your size prior to this as you can hold it up to the SIM tray and see.

Alex Hughes

Alex is a journalist who has written extensively about all things broadband, SIMs and phone contracts, as well as scouring the internet to land you the best prices on the very latest in gadgets and tech. Whether that be with the latest iPhones and Android handsets, breaking down how broadband works or revealing the cheapest SIM plans, he's in the know, and will help you land a bargain.