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EXCLUSIVE
OUR PICK
Unltd
texts
Unltd
minutes
100GB
of 4G data
1
month contract
£14.00
per month
  • Unrestricted tethering in the UK
  • No speed caps
  • Free delivery
OUR PICK
Unltd
texts
Unltd
minutes
160GB
of 5G data
24
month contract
£20.00
per month
  • Free delivery
  • 14 day returns policy
OUR PICK
Unltd
texts
Unltd
minutes
100GB
of 5G data
12
month contract
£20.00
per month
  • 6 months free Disney+
  • Special offers with O2 Priority
  • Free delivery
  • 14 day returns policy
OUR PICK
Unltd
texts
Unltd
minutes
50GB
of 5G data
12
month contract
£20.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
45GB
of 5G data
1
month contract
£20.00
per month
  • Unlimited social data
  • Unlimited streaming on Netflix and other apps
  • Free delivery
  • 14 day returns policy
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
EXCLUSIVE
Unltd
texts
Unltd
minutes
Unltd
5G data
12
month contract
£28.00
per month
  • Includes a £50 Amazon Gift Card
  • 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
20GB
of 4G data
1
month contract
£7.46
per month
  • 25% off for 3 months
  • Free delivery
  • 14 day returns policy
EXCLUSIVE
Unltd
texts
Unltd
minutes
20GB
of 4G data
1
month contract
£8.99
per month
  • Double data for 3 months
  • 100 international minutes to over 40 countries
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
20GB
of 4G data
1
month contract
£10.00
per month
  • Roam like at home
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
20GB
of 4G data
12
month contract
£10.00
per month
  • Free delivery
  • 14 day returns policy
EXCLUSIVE
Unltd
texts
Unltd
minutes
50GB
of 4G data
12
month contract
£12.00
per month
  • Includes data rollover
  • EU Roaming
  • Free delivery
  • 30 day returns policy
Unltd
texts
Unltd
minutes
36GB
of 4G data
12
month contract
£12.00
per month
  • Includes data rollover
  • EU Roaming
  • Free delivery
  • 30 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 5G data
12
month contract
£12.00
per month
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 5G data
12
month contract
£12.00
per month
  • Includes capping + data rollover
  • Free delivery
  • 14 day returns policy
Unltd
texts
Unltd
minutes
30GB
of 4G data
12
month contract
£12.00
per month
  • Free delivery
  • 14 day returns policy
EXCLUSIVE
Unltd
texts
Unltd
minutes
24GB
of 4G data
1
month contract
£12.00
per month
  • Free delivery
  • 14 day returns policy

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.

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
SMARTY sim only 100GB data 1 month £14.00
  • 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
  • SMARTY sim only
    4G
    • Exclusive
    • 100GB of 4G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Unrestricted tethering in the UK
    • £14.00 per month
    1 month contract From SMARTY

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.

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

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.

And just as importantly if you've got a long commute to work, you can stream endless video or play games online to stay entertained without racking up charges for excess usage.

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.

As for whether your unlimited data SIM really is unlimited, read our guide and we'll explain all.

Which networks offer unlimited data SIMs?

Unlimited SIM only deals on Vodafone

Provider Data Amount Contract Length Monthly Costs
Vodafone sim only Unlimited data 1 month £36.00
Vodafone sim only Unlimited data 1 month £36.00
  • Vodafone sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Maximum download speed 2mbps
    • £36.00 per month
    1 month contract From Vodafone
  • Vodafone sim only
    5G
    • Unlimited 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • Maximum download speed 2mbps
    • £36.00 per month
    1 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 100GB data 12 months £20.00
O2 sim only 100GB data 12 months £20.00
  • O2 sim only
    5G
    • 100GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • 6 months free Disney+
    • £20.00 per month
    12 month contract From O2
  • O2 sim only
    5G
    • 100GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • 6 months free Disney+
    • £20.00 per month
    12 month contract From O2
  • O2 sim only
    5G
    • 100GB of 5G data
    • Unlimited minutes
    • Unlimited texts
    • download speed limit
    • 6 months free Disney+
    • £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 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 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 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

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

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.

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

What to look for in unlimited data sim plans

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.

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 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.