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OUR PICK
Unltd
texts
Unltd
minutes
30GB
of 4G data
1
month contract
£10.00
per month
  • Unrestricted tethering in the UK
  • No speed caps
  • Free delivery
OUR PICK
Unltd
texts
Unltd
minutes
50GB
of 5G data
1
month contract
£30.00
per month
  • Special offers with O2 Priority
  • Free delivery
  • 14 day returns policy
OUR PICK
Unltd
texts
Unltd
minutes
100GB
of 4G data
1
month contract
£20.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
Unltd
5G data
12
month contract
£28.00
per month
  • Includes capping + data rollover
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
Unltd
5G data
1
month contract
£24.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
50GB
of 5G data
12
month contract
£25.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
20GB
of 4G data
1
month contract
£9.95
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
12
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
1
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
12
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 5G data
12
month contract
£10.00
per month
  • Up to 5 months free Apple Music
  • Bill capping and data rollover
  • Free delivery
  • 30 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
12
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
12
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
24GB
of 5G data
1
month contract
£10.00
per month
  • Up to 5 months free Apple Music
  • Bill capping and data rollover
  • Free delivery
  • 30 day returns policy
Unltd
texts
Unltd
minutes
20GB
of 5G data
12
month contract
£10.00
per month
  • Includes capping + data rollover
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
20GB
of 5G data
12
month contract
£10.00
per month
  • 3 months free Disney+
  • Special offers with O2 Priority
  • Free delivery
  • 14 day returns policy

Sims with unlimited data: All you need to know

Unlimited data SIM icon

Like to stream music on the go and watch Netflix on your commute? Is that causing you to run up high bills? You're best off with an unlimited data SIM deal. We've tracked down some of our best unlimited SIMs here.

Compare deals

Best unlimited data sims this week

Provider Data Amount Contract Length Monthly Costs
SMARTY sim only 30GB data 1 month £10.00
SMARTY sim only 50GB data 1 month £12.00
Talk Mobile sim only 100GB data 1 month £15.00
  • SMARTY sim only
    4G
    • 30GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £10.00 per month
    1 month contract From SMARTY
  • SMARTY sim only
    4G
    • 50GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £12.00 per month
    1 month contract From SMARTY
  • Talk Mobile sim only
    4G
    • 100GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £15.00 per month
    1 month contract From Talkmobile

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.

What are unlimited data SIMs?

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.

They're generally a bit more expensive than plans with usage limits, but that extra outlay means you won't have to worry about running out of data when you most need it.

Unlimited SIMs are ideal for heavy users. And they're just the ticket if you've got a long commute to work, because they free you to stream endless video or play games online to keep yourself entertained.

How do unlimited SIMs work?

Much like any other SIM, really. Just sign up, insert it in your smartphone and you're good to go.

As for whether there are any restrictions on your usage or whether unlimited really does mean unlimited, that's a slightly different question.

In practice, some networks offer 'truly unlimited usage', while others apply usage limits of between 650GB-1,000GB per month. Both of which are so generous that the average person could use their phone all day every.

Keen to know more about truly unlimited usage on SIMs? Read our guide and we'll explain all.

Our best unlimited data SIMs this week

Deals change week to week, but here's our hand-picked selection of the best unlimited data SIM-only deals available right now.

  • Three sim only
    5G
    • 100GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £12.00 per month
    12 month contract From Three Mobile
  • SMARTY sim only
    4G
    • 30GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £10.00 per month
    1 month contract From SMARTY
  • O2 sim only
    5G
    • 50GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Special offers with O2 Priority
    • £30.00 per month
    1 month contract From O2
  • GiffGaff sim only
    4G
    • 100GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    1 month contract From giffgaff
  • Virgin sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Includes capping + data rollover
    • £28.00 per month
    12 month contract From Virgin Mobile
  • Three sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £24.00 per month
    1 month contract From Three Mobile

Which networks offer unlimited data SIMs?

Unlimited data SIM only deals on Vodafone

Provider Data Amount Contract Length Monthly Costs
Vodafone sim only 100GB data 12 months £20.00
Vodafone sim only 100GB data 12 months £20.00
  • Vodafone sim only
    4G
    • 100GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    12 month contract From Vodafone
  • Vodafone sim only
    4G
    • 100GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    12 month contract From Vodafone

Vodafone offers three categories of unlimited data plans: Unlimited Lite, Unlimited and Unlimited Max, all of which let you use the internet as much as you like in the UK. There's no fair usage policy to restrict you.

However, it's worth noting that a usage cap of 25GB per month applies on Vodafone unlimited plans when you're overseas.

The principal difference between Vodafone's selection of unlimited SIM plans are the speeds they offer.

While Unlimited Lite gets you average speeds of 2Mbps, the standard Unlimited plan features average speeds of 10Mbps.

If you choose the top-of-the-range Unlimited Max plan, you'll get access to Vodafone's 5G network and the 'fastest available' speeds.

All Vodafone unlimited-data SIMs include a three-month trial of SecureNet, as well as inclusive roaming in 51 locations.

Vodafone also offers Unlimited Entertainment plans. These offer the same unrestricted data usage and speeds as the standard Unlimited plans outlined above, but come with a choice of a 12-month subscription to YouTube Premium, Amazon Prime Video or Spotify.

Unlimited SIM only deals on O2

Provider Data Amount Contract Length Monthly Costs
O2 sim only 50GB data 1 month £30.00
O2 sim only 50GB data 1 month £30.00
O2 sim only 50GB data 1 month £30.00
  • O2 sim only
    5G
    • 50GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Special offers with O2 Priority
    • £30.00 per month
    1 month contract From O2
  • O2 sim only
    5G
    • 50GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Special offers with O2 Priority
    • £30.00 per month
    1 month contract From O2
  • O2 sim only
    5G
    • 50GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Special offers with O2 Priority
    • £30.00 per month
    1 month contract From O2

O2 doesn't offer a huge selection of unlimited data SIMs, but they all afford you the freedom to use your phone in the UK without worrying about usage limits or excess charges.

As is the case with most networks, however, a fair usage cap applies. This limits your data usage to 650GB per month.

A data cap of 25GB is also in force if you're roaming in destinations in O2's Europe Zone.

All O2's unlimited data plans entitle you to daily offers with its Priority customer rewards app, as well as free O2 WiFi.

And select plans entitle you to a range of O2 Extras. These include six months' free Apple Music or Amazon Music Unlimited, or 12-month subscriptions to Audible, Amazon Prime Video or Calm.

Unlimited SIM only deals on Three

Provider Data Amount Contract Length Monthly Costs
Three sim only Unlimited data 1 month £24.00
Three sim only Unlimited data 1 month £24.00
Three sim only Unlimited data 1 month £24.00
  • Three sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £24.00 per month
    1 month contract From Three Mobile
  • Three sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £24.00 per month
    1 month contract From Three Mobile
  • Three sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £24.00 per month
    1 month contract From Three Mobile

Three unlimited SIMs stand out for being well priced and are all truly unlimited. That means there's no fair usage cap in the UK and you really can use as much data as you like.

And there are no restrictions on how much data you can use for tethering either.

However, a monthly cap of 20GB applies for using your phone when you're in any destination covered by Three's Go Roam in Europe.

And if you're in a location included in its Go Roam Around the World, the monthly data cap stands at 12GB.

Three's unlimited plans are available as one-month, rolling contracts or 12-month contracts. And 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 160GB data 24 months £20.00
EE sim only 160GB data 24 months £20.00
EE sim only 160GB data 24 months £20.00
  • EE sim only
    5G
    • 160GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    24 month contract From EE Mobile
  • EE sim only
    5G
    • 160GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    24 month contract From EE Mobile
  • EE sim only
    5G
    • 160GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • £20.00 per month
    24 month contract From EE Mobile

EE offers an extensive selection of unlimited data SIMs, with a choice of a 24-month contract or a one-month rolling contract.

All are subject to 600GB per month fair usage limit for data in the UK. Which should be plenty for all but the heaviest users.

When you're traveling, however, a much tighter fair usage cap applies. EE enforces a limit of 50GB per month on unlimited plans when you're roaming in its Europe Zone.

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.

Unlimited data SIMs on Smarty

Provider Data Amount Contract Length Monthly Costs
SMARTY sim only 30GB data 1 month £10.00
SMARTY sim only 30GB data 1 month £10.00
SMARTY sim only Unlimited data 1 month £16.00
  • SMARTY sim only
    4G
    • 30GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £10.00 per month
    1 month contract From SMARTY
  • SMARTY sim only
    4G
    • 30GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £10.00 per month
    1 month contract From SMARTY
  • SMARTY sim only
    4G
    • Unlimited 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • No speed caps
    • £16.00 per month
    1 month contract From SMARTY

Smarty's unlimited data plans are truly unlimited. This means there's no fair usage cap in the UK and you can use as much data as you like.

You'll also be able to use your UK allowances in the EU for no extra charge. But a fair usage cap of 12GB per month applies.

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.

Unlimited SIMs on BT Mobile

Unlimited SIMs from BT Mobile are solely available if you're a BT broadband customer and are signed up to its Halo service.

The good news, though, is that they're truly unlimited and aren't subject to a fair usage policy. So you can use as much data as you like when you're in the UK.

BT Mobile also throws in a free use of the BT Sport app on its unlimited data plans. Which means you'll be able to watch live sport on your phone while you're out and about.

Unlimited SIMs on Virgin Mobile

Virgin Mobile's unlimited SIMs are well priced and are truly unlimited. The upshot is there's no fair usage cap on data when you're using your phone in the UK.

A fair usage limit does apply when you're roaming, however.

The size of the cap depends on the price of your plan. But in tests we've conducted, the limit seems to come in at between 13GB-16GB.

Pros and cons of unlimited data SIMs

The good...

  • No need to worry about running out of data
  • No need to worry about excess usage charges, either

The bad...

  • More expensive than SIMs with usage limits
  • Only heavy mobile internet users get through enough data to make them worthwhile
  • Some networks apply speed restrictions
  • Some networks also apply restrictions on tethering

Alternatives to unlimited data SIM deals

Not sold on unlimited data, or can't find the right deal for you? You have other options. Take a look at...

  • SIM-only deals with high data allowances. Nearly all networks offer SIM plans with lots of data, often 100GB and above. These are usually a little cheaper than unlimited data, and still give you more than enough for the odd on-the-go Netflix binge.
  • Mobile contracts with unlimited data. Want a new phone as well as a SIM? You can get contracts on handsets with unlimited data. Compare phone contracts here.
  • Using free public Wi-Fi. This means you don't need to pay for unlimited data, but can use Wi-Fi for free when you're out and about.

How to switch to an unlimited data SIM plan

To switch to an unlimited data SIM plan, all you need to do is:

  • Check you're out of contract with your current mobile plan
  • Choose a new unlimited data deal and sign up
  • Cancel your old contract - and port your old number over, if you want to

By definition all unlimited data SIMs have the same mobile internet usage limit (subject to fair usage policies).

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.

Alternatives to unlimited data SIM deals

Pay As You Go SIM Cards

Affordable SIM Cards

Best all round SIM Cards

Data only SIM Cards

5G enabled SIM cards

Frequently asked questions

How do I find an unlimited data plan?

To find an unlimited data SIM head to the mobile SIM comparison table on this page and then...

  • 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 iPhones, Samsung Galaxy smartphones and more budget-friendly models 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 50GB per month. Meanwhile, Three customers with unlimited data are restricted to 20GB per month while travelling in locations covered by its Go Roam in Europe scheme.

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.