Unlimited Data SIM Plans

Always need a little more mobile data? Never run out again with an unlimited data SIM only deal!

Most mobile networks now offer fantastic deals on unlimited data SIM plans to accomodate customers that burn through their data every month, some with great perks like reduced monthly contracts and perks like free streaming and 5G capability.

Is your data really "Unlimited"?
If you're looking for a SIM plan with Unlimited data it's important to know what you're getting.

Many "unlimited" SIM plans currently have limits on the speeds which you can use your data - For example giffgaff limit your speed once you reach a certain data cap and Vodafone have large variations in the speeds which certain plans can reach (2mbps for their £22 Unlimited Lite plan). Knowing what you need unlimited data for means you can make the right decision.

If you're looking for an Unlimited Data SIM, let's get started!

three logo
Three
24 Month Contract

Our pick:
It's hard to deny that 50% off Three's unlimited contract is a great deal, but with it's 100% unlimited, uncapped data you won't be disappointed.

Unlimited Data
£10 / month
Unlimited Minutes
Unlimited Texts
50% Off For 6 Months - Then £20
No Data Or Speed Caps
More Info
Check Three coverage
where you live

Free 30GB Wifi Hotspot

Free Roaming In 71 Countries

Use popular apps without using your data.

  • Stream your favourite shows and music infinitely without using up your data
  • Connect other devices to your phone hotspot and use your data allowance to get online
  • Access exclusive offers and treats - Only for Three customers
  • Use your phone abroad in 71 destinations at no extra cost
  • One month SIM also available
three logo
Three
12 Month Contract

Limited time deal:
Don't miss this super-low £16 deal - it won't stick around for long (usual price £20 - save £48)

Unlimited Data
£16 / month
Unlimited Minutes
Unlimited Texts
No Data Or Speed Caps
More Info
Check Three coverage
where you live

Free 30GB Wifi Hotspot

Free Roaming In 71 Countries

Use popular apps without using your data.

  • Stream your favourite shows and music infinitely without using up your data
  • Connect other devices to your phone hotspot and use your data allowance to get online
  • Access exclusive offers and treats - Only for Three customers
  • Use your phone abroad in 71 destinations at no extra cost
  • One month SIM also available
three logo
Three
1 Month SIM
Unlimited Data
£26 / month
Unlimited Minutes
Unlimited Texts
No Data Or Speed Caps
More Info
Check Three coverage
where you live

Free 1GB Wifi Hotspot

Rolling Contract

  • Flexible 1 month plan - You can choose to cancel after one month or carry on using it.
  • Go Roam Around the World in 71 destinations, at no extra cost - More Details
smarty logo
Smarty
1 Month SIM
Unlimited Data
£20 / month
Unlimited Minutes
Unlimited Texts
No Credit Check
No Contract
More Info
Check Smarty coverage
where you live

Keep your price low for life

Rolling Contract

No Credit Check Required

  • Refer a friend and you both get a free month
  • Use in Europe for no extra cost
  • Powered by Three
  • Simple and flexible SIM only deal - Change whenever you like at no extra cost
vodafone logo
Vodafone
24 Month Contract
Unlimited Data
£26 / month
Unlimited Minutes
Unlimited Texts
Unlimited Max
Save £96
More Info
Check Vodafone coverage
where you live

Fastest Available Data Speeds

5G Ready Contract

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 81 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
24 Month Contract
Unlimited Data
£22 / month
Unlimited Minutes
Unlimited Texts
Save £96
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

3 Mo Free Security

51 Roaming Locations

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 81 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
24 Month Contract
Unlimited Data
£22 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Max 2Mbps data speeds

3 Mo Free Security

51 Roaming Locations

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 81 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
24 Month Contract
Unlimited Data
£29 / month
Unlimited Minutes
Unlimited Texts
12 Mo Free Entertainment
Save £96
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

Free Roaming in 51 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • Choice of streaming service for one year - Sky Sports mobile, Now TV, Spotify or Prime Video
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
24 Month Contract
Unlimited Data
£33 / month
Unlimited Minutes
Unlimited Texts
12 Mo Free Entertainment
Save £96
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

5G Ready Contract

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • Choice of streaming service for one year - Sky Sports mobile, Now TV, Spotify or Prime Video
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
12 Month Contract
Unlimited Data
£36 / month
Unlimited Minutes
Unlimited Texts
12 Mo Free Entertainment
More Info
Check Vodafone coverage
where you live

Fastest Available Data Speeds

12 Mo Free Entertainment

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • Choice of streaming service for one year - Sky Sports mobile, Now TV, Spotify or Prime Video
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 77 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
12 Month Contract
Unlimited Data
£32 / month
Unlimited Minutes
Unlimited Texts
12 Mo Free Entertainment
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
12 Month Contract
Unlimited Data
£30 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Fastest Available Speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
12 Month Contract
Unlimited Data
£26 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
12 Month Contract
Unlimited Data
£23 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Max 2Mbps data speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
1 Month Contract
Unlimited Data
£32 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Fastest Available Data Speeds

12 Mo Free Entertainment

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • Choice of streaming service for one year - Sky Sports mobile, Now TV, Spotify or Prime Video
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 77 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
1 Month Contract
Unlimited Data
£28 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Max 10Mbps data speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!
vodafone logo
Vodafone
1 Month Contract
Unlimited Data
£25 / month
Unlimited Minutes
Unlimited Texts
More Info
Check Vodafone coverage
where you live

Fastest Available Speeds

Free Roaming in 48 Countries

3 Mo Free Security

  • Upgrade to a new phone after only 3 months, with no hidden charges or penalties. Ideal to get great-value data, minutes and texts while you wait for the latest phone
  • 3-month free trial of Vodafone Secure Net
  • Pay no roaming charges in 48 destinations worldwide, including the USA, Australia and Canada – that’s more than any other UK network!

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What is an Unlimited Data SIM Plan?

On the face of it, an Unlimited data SIM plan is a mobile sim contract that allows you to use an unlimited amount of data each month (this could be a 1-month SIM or longer contract). However when you compare Unlimited data plans available right now you can see that:

a) Not all "unlimited" data sim plans offer the same experience to the user.
b) Aren't available for all customers to apply for.

There are quite a few unlimited data plans provided by UK networks and we'll go over the differences in this guide.

Which Networks Provide Unlimited Data SIM Plans?

Three - Three have offered customers unlimited data on some of their SIM contracts for a while and are one of the few networks which offer fully unlimited data with no caps or throttling involved. Three do monitor for usage over 1000GB per month but this would only be hit if a SIM was being used in an improper way and is extremely unlikely for a normal customer. Three offer unlimited data with 1-month, 12-month or 24-month contracts.

giffgaff - giffgaff are another UK network that have offered unlimited data in their "Always-On" plans. There is, however, terms and conditions attached whereby customers do have their speeds restricted once they use 20GB of data. From then on data speeds are reduced to 384kbps from 8am to midnight. For comparison, normal 4g speed is 14.61 Mbps so customers would see ~97% speed reduction from the average level.

Vodafone - Vodafone are one of the latest networks to offer customers unlimited data allowances on some of their SIM contracts. They provide 3 "tiers" of plan however which is based on the speeds the customer can use their unlimited allowance.

a) Unlimited Lite: Maximum download speeds of 2mbps.
b) Unlimited: Maximum download speeds of 10mbps.
c) Unlimited Max: the fastest speed available.

Smarty - Smarty's Unlimited data plan is run by Three. The plan is essentially the same as Three except for variations in cost depending on when sales are being run.

Virgin Mobile - Unfortunately, Virgin's unlimited plan is only available to customers with Virgin TV or Broadband. Despite this, the cost of their unlimited data allowance is much more than the others.

Who Are Unlimited Data Plans For?

It used to be the case that most of us could get by on 1-2GB of data per month due to the low amounts of data being used every day. Now with more and more of our lives taking place online and more importantly over our phones, the amount of data we use is going up.

Streaming platforms, constant social media feeds, higher-res images and videos are all eating up our data every month and it doesn't show any signs of slowing down. Unlimited data SIM plans do away with the worry of running out of data every month and can even help by providing a wifi hotspot for when you're out and about - Some people even replace their home wifi where a great mobile signal is available.

If you're always juggling your data allowance then an unlimited sim is an affordable way of getting the most from your mobile and giving you the flexibility of putting your SIM into any new phone you get.

Which Unlimited SIM Plan Is Best?

We've already outlined how the various Unlimited plans are different for each network and you can browse the offers above to find one that suits your budget...

...but without a doubt the best combination of affordability and practicality is Three Mobile's Unlimited 24-month SIM plan.

Their current offer of 6 months at £10p/m is too good to miss out on at the moment and because they offer truly unlimited data (no caps, no throttling unlike others), it's the perfect solution if you want a contract you can buy once and never worry about again. (you can even get a 12-month and 1-month version).