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Unlimited data SIM only deals

If you don’t want any restrictions on the amount of data you use with your mobile phone, an unlimited data SIM only deal is the way to go. Most UK networks now offer unlimited data deals to suit a range of budgets.

Uswitch tips

How do I switch and keep my number?
Thumbnail, graphic - SIM cards from different networks. Uswitch compares deals from Lebara Mobile, O2, iD Mobile, Three, Vodafone and others.

1. Choose your new deal
Select a deal below and click through to the network’s site.

2. Get your PAC code
You’ll need a special code to keep your number when you switch. It's quick and free:
Text PAC to 65075 to receive your code.

3. Give the code to your new network
Contact the new network after signing up to provide them with your PAC code, which will begin the process and will automatically cancel your previous plan. Alternatively, you can enter the PAC code when signing up on the network’s site.

O2 SIM deal

O2 logo

£18.00 a monthMonthly cost will rise every April by inflation (RPI) plus 3.9%.

12 month contract

250 GBof 5G data

Promoted
  • EU roaming included
  • 3 months Free Amazon Prime
  • Best Network for Roaming

List of SIM Only deals

Sorted by: Uswitch Promoted

  1. giffgaff SIM deal

    Uses O2's Network

    giffgaff logo

    £25.00 a month

    18 month contract

    Unlimited5G data

    Promoted
    • No price rise in 2024
    • EU roaming included
  2. Lebara Mobile SIM deal

    Uses Vodafone's Network

    Lebara Mobile logo

    £9.98 a monthfor 3 months, then £24.95

    No contract

    Unlimited5G data

    Uswitch Exclusive
    Promoted
    • No price rise in 2024
    • EU roaming included
    • Most Popular Mobile Network
  3. Talkmobile SIM deal

    Uses Vodafone's Network

    Talkmobile logo

    £16.00 a month

    1 month contract

    Unlimited5G data

    Promoted
    • No price rise in 2024
    • EU roaming included
  4. SMARTY SIM deal

    Uses Three's Network

    SMARTY logo

    £16.00 a month

    1 month contract

    Unlimited5G data

    Promoted
    • No price rise in 2024
    • EU roaming included
    • Best SIM Only Network
  5. iD Mobile SIM deal

    Uses Three's Network

    iD Mobile logo

    £16.00 a month

    1 month contract

    Unlimited5G data

    • No price rise in 2024
    • Claim 3 months free Apple Music and Arcade
    • Free roaming up to 30GB
    • Best Network for Data
  6. iD Mobile SIM deal

    Uses Three's Network

    iD Mobile logo

    £8.50 a monthfor 3 months, then £17.00

    12 month contract

    Unlimited5G data

    • No price rise in 2024
    • Claim 3 months free Apple Music and Arcade
    • Free roaming up to 30GB
    • Best Network for Data
  7. Asda Mobile SIM deal

    Uses Vodafone's Network

    Asda Mobile logo

    £20.00 a month

    1 month contract

    Unlimited5G data

  8. Honest Mobile SIM deal

    Uses Three's Network

    Honest Mobile logo

    £12.50 a monthfor 2 months, then £25.00

    No contract

    Unlimited5G data

    • No price rise in 2024
  9. Three Mobile SIM deal

    Three Mobile logo

    £23.00 a monthMonthly cost will rise every April by inflation (CPI) plus 3.9%.

    12 month contract

    Unlimited5G data

    • Three+ rewards app
  10. spusu Mobile SIM deal

    Uses EE's Network

    spusu Mobile logo

    £29.90 a month

    1 month contract

    Unlimited5G data

    • No price rise in 2024
    • EU roaming included
  11. Three Mobile SIM deal

    Three Mobile logo

    £22.00 a monthMonthly cost will rise every April by inflation (CPI) plus 3.9%.

    24 month contract

    Unlimited5G data

    • Three+ rewards app
  12. Three Mobile SIM deal

    Three Mobile logo

    £31.50 a month

    No contract

    Unlimited5G data

    • Inclusive roaming
    • Three+ rewards app
  13. giffgaff SIM deal

    Uses O2's Network

    giffgaff logo

    £35.00 a month

    No contract

    Unlimited5G data

    • No price rise in 2024
    • EU roaming included
  14. Honest Mobile SIM deal

    Uses Three's Network

    Honest Mobile logo

    £11.25 a monthfor 3 months, then £22.50

    12 month contract

    Unlimited5G data

    Uswitch Exclusive
    • No price rise in 2024
  15. VOXI SIM deal

    Uses Vodafone's Network

    VOXI logo

    £35.00 a month

    No contract

    Unlimited5G data

    • No price rise in 2024
  16. Asda Mobile SIM deal

    Uses Vodafone's Network

    Asda Mobile logo

    £22.00 a month

    1 month contract

    Unlimited5G data

  17. Sky Mobile SIM deal

    Uses O2's Network

    Sky Mobile logo

    £40.00 a month

    12 month contract

    Unlimited5G data

    • No price rise in 2024
    • Data rollover
    • Best Network for Perks
  18. Tesco Mobile SIM deal

    Uses O2's Network

    Tesco Mobile logo

    £30.00 a monthMonthly cost will rise every April by inflation (CPI) plus 3.9%.

    12 month contract

    Unlimited5G data

    • Flexible cap on spending
    • Network of the Year
  19. Three Mobile SIM deal

    Three Mobile logo

    £31.00 a month

    1 month contract

    Unlimited5G data

    • Three+ rewards app
Can't find what you're looking for?

Uswitch services are provided at no cost to you, but we may receive a commission from the companies we refer you to. If a deal is "promoted" on Uswitch's tables, then it has been lent additional visibility as a result of us securing exclusivity on a great deal, or a commercial agreement to showcase what we believe to be market-leading value to consumers. Learn more about how our site works.

Please note: Mobile networks may increase monthly prices in line with the retail or consumer price index each year during the length of your contract. Please refer to individual network's terms and conditions before signing up.

What is unlimited data?

As the name suggests, unlimited data means you get unlimited access to the internet on your mobile device, with no monthly data cap. That means you’ll never run out of data to surf the web, browse social media and stream content. It also means you’ll never have to deal with surprise data charges in your bills.

Mobile deals with unlimited data generally cost more than those with a cap on the amount of data you get. But the upside is, there will never be a moment when you have to worry about running out of data. You’ll be able to stream, upload, download, chat and message as much as you want.

How to get cheap unlimited data deals?

Unlimited data SIM only deals usually cost more than deals with a set amount of data. But you can still find a deal that suits your budget by comparing offers from a wide range of mobile networks, such as Vodafone, O2, Three, and more.

What are the benefits of unlimited data deals?

The main benefit of an unlimited data deal is never running out of mobile data. So, even if you’re miles away from a Wi-Fi connection, you won’t have to worry about using lots of data on streaming a show or running an online playlist all day. It’s the best way to ensure you always have data when you need it.

Alternatives to unlimited SIM only plans

If you don’t want to go for an unlimited data SIM only deal but still require a lot of data, you can simply opt for a plan that caps your limit at a high number, like 100-200GB. Most networks provide deals with extremely high data caps, so compare SIM only deals on Uswitch today to find a price plan that suits your needs.

Other SIM only deals include pay as you go SIMs, 12 month SIM deals, no credit check SIMs, iPhone SIM deals, 30-day SIM deals and 5G SIM deals.

Is there a limit to the amount of data I can use?

There’s no data cap on an unlimited data SIM only deal. You’re free to use as much mobile data as you like on your smartphone. There may be an instance where a fair usage policy is applied, but this will come down to individual networks. So check the fine print of your deal before you commit. But generally, unlimited means unlimited.

Most unlimited data SIM only deals will not have any restrictions and you’ll be able to download as much data as you want. Some networks may include a fair usage policy. But even if that’s the case, it won’t kick in after you’ve used more than enough data for most consumers. Check with your network to see what their specific policy is.

Which providers offer unlimited data deals?

You can get an unlimited data SIM only deal on most major UK networks.

Here’s a quick look at some of the extras you can get:

Vodafone

With Vodafone you can add up to three "Xtra benefits" to your unlimited plan, including romaing in up to 83 destinations. You can also add entertainment subscriptions – such as Spotify Premium, YouTube Premium and Amazon Prime – for as little as £8 a month.

You can also get unlimited 5G SIM only data plans at three different speed levels, similar to a broadband package.

Three

Three’s SIM only unlimited data deals are attractively priced and can be picked up on 30-day rolling or 12-month contracts. They’re all 5G-ready as standard too, with no caps or fair usage policy.

giffgaff

Choose giffgaff’s ‘golden goodybag’ add-on to get unlimited 5G data and free international roaming (although this has a 20GB per month cap limit).

Tesco Mobile

Tesco Mobile’s unlimited SIM only offerings are competitively priced. And since Tesco Mobile runs on O2’s network, you’ll enjoy 99% 4G coverage across the UK, as well as 5G coverage in a wide range of locations.

O2

O2’s unlimited data SIM only price plans begin at around £30 a month and can include exciting extras like discounts on Amazon Prime and Disney Plus. You’ll also enjoy 5G as standard with no speed restrictions.

And O2 is so far one of the only major UK networks that hasn’t reintroduced roaming charges in the EU. So you’ll be able to use your O2 data while travelling to EU countries.

SMARTY

SMARTY offers an unlimited SIM only data plan on a monthly rolling contract. There are no tethering restrictions and you don’t need to pass a credit check.

Will I lose service if I switch to a SIM only deal with another network?

No, you won’t lose any service by switching networks to a new SIM only deal.

How easy is it to switch networks?

Switching networks on a SIM only deal is incredibly easy thanks to Text to Switch.

All you need to do is text PAC to 65075 to receive your PAC code. You then give this to your new network who’ll be able to port over your current phone number. As long as you’re out of contract, you don’t even need to speak to your old network.

FAQs

Is unlimited data really unlimited?

Yes, in most cases unlimited means unlimited - so no data cap at all. Some networks may operate with a fair usage policy, so check before you sign up if that’s something you’re not sure of.

Does unlimited data mean unlimited hotspot?

Different networks will have different policies on using your unlimited data for hotspot, so check their terms and conditions before you commit to a plan.

If I have unlimited data do I need wifi?

No, with an unlimited data SIM only deal you’ll never need to log into wi-fi if you don’t want to. However, there may be occasions where a wi-fi connection is faster than mobile data so where you turn wi-fi on in some scenarios is up to you.

Can I use my unlimited data SIM abroad?

Different networks will have different policies on using your unlimited data abroad. Check up on your network’s roaming policy before you travel to be sure.

Can I get unlimited 5G data?

Yes, most networks now include 5G as standard with their SIM only deals, including on unlimited data plans.

What can I do with my old SIM?

If you have an old SIM card you no longer use, you can simply throw it away when you get your new unlimited data SIM.

Are unlimited data sims more expensive?

Yes, unlimited data SIM only deals will usually be more expensive than a deal that comes with a data cap. However, that doesn’t mean you can’t shop around to find a suitably priced deal for your budget.