Compare unlimited data SIM-only deals

Unlimited data SIM icon

Always using your smartphone? Like to stream music on the go, watch iPlayer on the train, and download lots of files? You could be in the market for a SIM deal with unlimited data.

How to find an unlimited data SIM deal

It's easy... Just use a mobile SIM comparison tool like ours:

  • Adjust the filters at the side to include just those deals with unlimited data, or at least a nice high data allowance
  • You can filter for other things too, such as minutes and texts allowances, networks, and budget.
  • If you're only interested in unlimited data plans, bear in mind that your options are (ironically enough) a little more limited.
Best buy deals
  • GiffGaff sim only
    • Unlimited 4G data
    • Unlimited minutes
    • Unlimited texts
    • Speed restrictions apply after 20GB of data use
    • £25.00 per month
    1 month contract From giffgaff
  • O2 sim only
    • 50GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • £30.00 per month
    12 month contract From O2

Who offers unlimited data SIMs?

Annoyingly, unlimited data is still quite rare in the mobile world - but it does exist. A couple of networks have SIM plans that give you unlimited data every single month. Here they are…


  • Three has its famous 'All-you-can-eat' data SIM - unlimited data paired with a variety of text and calling allowances. There's a fair usage cap of 1000GB data per month, but you're very unlikely to reach that.
  • You have the choice of getting a 12-month or 30-day contract, with 12-month plans costing less per month. You can also choose between an Essential plan, which has just your basic tariff, or an Advanced one, which has extra roaming and lets you use your phone for tethering.
  • Tethering, by the way, is subject to fair use here too - you can't use more than 30GB. Still, on your phone you can browse, download, and stream to your heart's content.


  • With a giffgaff SIM, you can nab a 30-day goodybag with 'Always On' data, which gives you an unlimited data allowance. Bear in mind, however, that it isn't truly unlimited. While you really can download and upload as much data as you like, giffgaff slows your download speed down significantly once you've used 6GB in a month.
  • Get this one if you rarely use more than 6GB but don't want to pay out the wazoo for add-ons in the months that you do.
  • On the other hand, if you're a big mobile internet user and need a lot more data than that, look to Three or another network with large allowances instead.

The best data-heavy SIM-only deals

Although your options for SIM deals with unlimited data are limited to just a couple of networks, there are plenty of providers that offer plans with heavy data allowances or particularly good 4G.

  • EE - Offers SIM-only deals with up to 40GB of monthly data, and contracts with even more. EE also has the advantage of offering faster 4G than any other network - you can reach maximum download speeds of 90Mb in some areas - and the widest 4G coverage.
  • O2 - Has SIM deals with up to 30GB data, plus contract plans with more. You also get perks like priority concert tickets and high street discounts.
  • Vodafone - Offers up to 40GB on SIM-only and more on phone contracts. Red plans even include extras like subscriptions for entertainment apps.
  • BT Mobile - Gives you up to 15GB data per month. It also uses EE's network to reach you, so you get great coverage - though sadly not the same top speeds as EE.
  • Virgin Mobile - Has up to 20GB SIM plans, and also uses EE so coverage is excellent. Some apps can be used data-free on Virgin Mobile without eating into your allowance, and any data you don't use is rolled over to the next month.

Can I get a mobile contract with unlimited data?

Yep - there are plenty of contracts on handsets that include unlimited data too.

  • They're offered by the same networks as above, so once again your options are a little limited, but landing a deal is totally possible.
  • You'll find unlimited data plans on a huge variety of handsets, including big ones like the iPhone XS and Samsung Galaxy S9 Plus, and more budget-friendly smartphones too.
  • It's also worth noting that many networks offer higher data allowances on phone contracts than they do on their SIM-only plans. If you can settle for, say, 20GB or 30GB of monthly data, your options for a contract plan open right up. It's worth considering if you fancy a new phone.

Pay-as-you-go SIM-only deals

If a long-term mobile contract doesn't appeal, you can always go for a Pay As You Go (PAYG) SIM deal - a great option if you want to keep your old handset.


You could also trade in your current smartphone and put the money towards one of the newer models. It's a quick and easy process with Depending on what model you have, and how intact it is, you’ll be surprised at what you can get.