Best unlimited data SIM deals in October 2020

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30GB
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12
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£12.00
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  • Free delivery
  • 14 day returns policy
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Sims with unlimited data: All you need to know

Unlimited data SIM icon

Always using your smartphone? Like to stream music on the go, watch Netflix on the train, and download lots of apps? Is all that causing you to run up unexpected highly bills for exceeding your data limit? You're best off with an unlimited data SIM deal.

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Best unlimited data sims this week

Provider Data Amount Contract Length Monthly Costs
GiffGaff sim only Unlimited data 1 month £25.00
SMARTY sim only Unlimited data 1 month £18.00
  • GiffGaff sim only
    4G
    • Unlimited 4G data
    • Unlimited minutes
    • Unlimited texts
    • Speed restrictions apply after 40GB of data use
    • £25.00 per month
    1 month contract From giffgaff
  • SMARTY sim only
    4G
    • Unlimited 4G data
    • Unlimited minutes
    • Unlimited texts
    • £18.00 per month
    1 month contract From SMARTY

Unlimited data SIM cards effectively allow you to use the internet on your phone as much as you like with no risk of running up high bills for exceeding your usage limit.

And, just as importantly, no more worrying about running out of data either.

You'll find our pick of the best UK unlimited data SIM only deals in the table above. All of which have been handpicked by our experts, taking into account price, coverage, speeds, reward schemes and more.

Is 'unlimited data' really unlimited? Read our guide to get up to speed.

Which networks offer unlimited data SIMs?

Unlimited SIM only deals on Vodafone

Provider Data Amount Contract Length Monthly Costs
Vodafone sim only Unlimited data 24 months £22.00
  • Vodafone sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • Maximum download speed 2mbps
    • £22.00 per month
    24 month contract From Vodafone

All Vodafone unlimited-data SIMs include a three-month trial of SecureNet. Depending on the plan you choose, you'll be able to use your UK allowances in 48 or 77 destinations overseas for no extra charge.

And on select unlimited plans, you'll be able to choose from a free, 12-month subscription to Now TV, Sky Sports Mobile, Amazon Prime Video or Spotify.

Unlimited SIM only deals on O2

Provider Data Amount Contract Length Monthly Costs
O2 sim only 100GB data 12 months £20.00
  • O2 sim only
    5G
    • 100GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • £20.00 per month
    12 month contract From O2

O2 unlimited data SIMs generally start from a shade over £30 per month and include daily offers with its Priority customer rewards app, as well as free O2 WiFi.

Unlimited SIM only deals on Three

Provider Data Amount Contract Length Monthly Costs
Three sim only 30GB data 12 months £12.00
Three sim only Unlimited data 12 months £18.00
  • Three sim only
    5G
    • 30GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • £12.00 per month
    12 month contract From Three Mobile
  • Three sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • £18.00 per month
    12 month contract From Three Mobile

Three unlimited SIMs stand out for being well priced and are available as one-month, rolling contracts or 12-month contracts.

Depending on whether you choose an Essential or Advanced plan, you'll get inclusive roaming in 48 or 77 locations.

Unlimited data SIM only deals on EE

Provider Data Amount Contract Length Monthly Costs
EE sim only 60GB data 12 months £27.00
  • EE sim only
    5G
    • 60GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • £27.00 per month
    12 month contract From EE Mobile

Select EE unlimited data plans include benefits you can swap from month to month, such as BT Sport and passes that allow you use streaming services or social media sites without eating into your data allowance.

It's also worth noting that EE is consistently named the UK's best network for mobile internet coverage and speeds.

Unlimited data SIMs on Smarty

Provider Data Amount Contract Length Monthly Costs
SMARTY sim only Unlimited data 1 month £18.00
  • SMARTY sim only
    4G
    • Unlimited 4G data
    • Unlimited minutes
    • Unlimited texts
    • £18.00 per month
    1 month contract From SMARTY

Get an unlimited data deal on Smarty and you'll be able to use your UK allowances in the EU, for no extra charge.

Smarty SIMs also allow you to tether, so you'll be able to use your plan to get online with other internet-enabled devices, such as a laptop or tablet.

One caveat to be aware of: unlike most of its plans, Smarty unlimited data plans don't offer money back for any data left unused at the end of the month.

SIM only plans with unlimited internet - what to look for

Of course, by definition all unlimited data SIMs have the same mobile internet usage limit. So when you're choosing between them, you're going to want to look at price and customer incentives to help make your mind up.

Cheapest unlimited data SIMs

As long as you're not too fussed about sweeteners, such as reward schemes and freebies, you can usually get an unlimited data SIM from just under £20 per month.

Be sure to look out for Three and Smarty, both of whom usually offer very keenly priced unlimited data deals.

Best unlimited data SIMs with freebies

EE, O2 and Vodafone all offer unlimited data SIMs that get you appealing freebies to go with your bottomless data limit. But expect to pay £25 per month or more.

Other available SIM cards

Pay As You Go SIM Cards

Affordable SIM Cards

Best all round SIM Cards

Data only SIM Cards

Frequently asked questions

How do I find an unlimited data plan?

To find an unlimited data sim 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.

Can I get a mobile contract with unlimited data?

Yes - 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.

Can I use my unlimited data abroad?

Although unlimited data plans effectively allow you to use the internet as much as you like when you're in the UK, tighter restrictions on your usage apply when you're overseas.

EE, for instance, allows customers on unlimited data tariffs to use just 15GB of data overseas before charges apply.

While Three customers with unlimited data are restricted to 19GB per month while travelling in the EU.

Does EE offer unlimited data?

EE offers a selection of unlimited data SIM only deals, all of which also get you unlimited calls and texts too.

While EE SIMs with unlimited data aren't the cheapest by any means, they feature some great benefits and freebies, such as a free 6-month Apple Music subscription and inclusive EU roaming.