iD Mobile SIM Deal
Uses Three Mobile's Network
£15.00 a month
1 month contract
Unlimited5G data
Promoted
Look for
No price rise
in your resultsUnlimited 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
Do I need an unlimited data SIM only deal?
Unlimited data plans tend to be more expensive, so it’s worth considering whether you truly need one. The average mobile user in the UK consumes around 9.9GB of data per month. However, if you frequently stream, game, or engage in other data-heavy activities, an unlimited plan could be the perfect choice for you.
How to get the best unlimited data SIM only deal?
To get the best unlimited data SIM only deal, compare network coverage, contract flexibility, perks like roaming or international calls, and overall price. Look for short-term contracts if you want flexibility or long-term deals for better savings.
List of SIM Only deals
giffgaff SIM Deal
Uses O2's Network
£14.00 a month
18 month contract
Unlimited5G data
PromotedeSIM compatibleLebara Mobile SIM Deal
Uses Vodafone's Network
£9.98 a monthfor 3 months, then £24.95
No contract
Unlimited5G data
ExclusivePromotedTalkmobile SIM Deal
Uses Vodafone's Network
£16.00 a month
1 month contract
Unlimited5G data
PromotedeSIM compatibleSMARTY SIM Deal
Uses Three Mobile's Network
£17.00 a month
1 month contract
Unlimited5G data
PromotedeSIM compatibleiD Mobile SIM Deal
Uses Three Mobile's Network
£8.00 a monthfor 3 months, then £16.00
12 month contract
Unlimited5G data
PromotedeSIM compatibleSky Mobile SIM Deal
Uses O2's Network
£20.00 a monthMonthly cost may rise in contract
12 month contract
Unlimited5G data
ExclusivePromotedeSIM compatibleiD Mobile SIM Deal
Uses Three Mobile's Network
£15.00 a month
1 month contract
Unlimited5G data
eSIM compatiblegiffgaff SIM Deal
Uses O2's Network
£20.00 a month
No contract
Unlimited5G data
eSIM compatibleThree Mobile SIM Deal
£20.00 a monthuntil April 2027then price rises every April in contract by £2.30
12 month contract
Unlimited5G data
eSIM compatibleTesco Mobile SIM Deal
Uses O2's Network
£17.00 a monthuntil April 2027then price rises in April 2027 by £1.02 and in April 2028 by £1.08
24 month contract
Unlimited5G data
eSIM compatible
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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.
Compare our best 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.
Which providers offer unlimited data deals?
Unlimited data SIM only deals usually cost more than deals with a set amount of data. However, you can still find a deal that suits your budget by comparing offers from a wide range of mobile networks, such as giffgaff, SMARTY, Three, and more.
Do I need an unlimited data SIM only deal?
Unlimited data plans tend to be more expensive, so it’s worth considering whether you truly need one. The average mobile user in the UK consumes around 10.7GB of data each month, according to a recent report from Ofcom. However, if you frequently stream, game, or engage in other data-heavy activities like tethering your laptop to your phone, an unlimited plan could be the perfect choice for you.
| Smartphone app or activity | Approx data usage over an hour | Notes |
|---|---|---|
| Using Spotify | 40MB -150MB | 40MB refers to listening to audio at Spotify’s normal quality, while listening using its very high quality function would use up to 150MB |
| Watching YouTube HD | 1.5GB - 3GB | Watching videos at 720p would equate to around 1.5GB per hour, while Full HD would consume up to around 3GB |
| Watching Netflix HD | 3GB | Streaming Netflix content for an hour using its standard HD setting would equate to around 3GB |
| Scrolling TikTok | 800MB - 1.2GB | TikTok preloads forthcoming clips in the background of a user’s feed, which would burn up to 1.2GB an hour under standard settings |
| Making video calls | 250MB - 1.2GB | Making a call using Zoom or Microsoft Teams over the course of an hour would use around 1.2GB of data |
| Using WhatsApp | 1MB - 350MB | Simply exchanging messages over WhatsApp would use very little data at all (~1MB, whereas an hour-long video call would use up to 350MB an hour under standard settings |
How to get the best unlimited data SIM only deal?
To get the best unlimited data SIM only deal, compare network coverage, contract flexibility, perks like roaming or international calls, and overall price. Look for short-term contracts if you want flexibility, or long-term deals for better savings.
What is an unlimited data SIM only deal?
As the name suggests, unlimited data means unlimited internet access on your mobile device without a monthly data cap. While these deals generally cost more than those with a data cap, 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.
Most of the offers on the deals table include unlimited 5G data, so make sure your phone is 5G compatible, which is the case with all of the most recent flagship phones. Knowing if you have 5G coverage in your local area is equally important.
For more information, see our Best mobile network coverage in the UK guide.
Who should buy an unlimited data SIM only deal?
Whether an unlimited data SIM only deal is the right fit for you fully hinges on how much data you’re likely to use each month.
- I mostly use Wi-Fi: If you rarely use data for much more than sending the odd email or checking social media, you’re probably better off with a PAYG deal, or a cheap contract for between 3-10GB of data each month.
- I commute every day: If you’re regularly commuting into the office, you’ll probably need a reliable data connection to get some work done or to decompress at the end of the day. You’re best suited to a plan that gives you between 10GB and 20GB; which is the average monthly data allowance for most smartphone users.
- I regularly stream Netflix in HD: Streaming HD video can rapidly burn through low data allowances. Habitual streamers of high quality video platforms over 5G are likely to be in need of a plan with between 20GB and 50GB, though you may want to consider an unlimited plan for peace of mind.
- I frequently use my phone as a hotspot: Tethering additional devices like a laptop to your phone to take advantage of its 5G connection is a surefire way to use a lot of data. An unlimited data plan is a safe bet to make sure you stay connected, regardless of the device.
- I’m a regular traveller: People who regularly travel abroad for work or play may be the best candidates for an unlimited data plan with generous roaming allowances.
Unlimited isn't always the cheapest option
Although some customers may feel reassured by an unlimited data plan’s safety net, they’re not always the cheapest—or most suitable—option. It’s worth remembering that regular monthly deals have the exact same coverage and speeds as unlimited plans, all that extra data is the sole advantage. So unless you’re watching a lot of high-definition videos, making video calls, playing games and tethering multiple devices off your phone, you might be paying over the odds for data you’ll never actually use.
A lot of unlimited data plans don’t strictly live up to their name, either. Some tend to throttle data after you’ve surpassed 50GB of usage, for example, so it’s technically a capped plan in all but name.
Many people overestimate just how much data they need. The average monthly data consumption in the UK is 10.7GB, according to a recent report from Ofcom, meaning a 20GB SIM deal would be more than adequate for most people’s data usage. While a 20-30GB SIM typically costs £6-£8 a month, unlimited plans typically cost around £15-£18 a month on average, meaning switching to the lower data allowance could save you between £8-£12 a month.
The best way to work out how likely you are to need an unlimited plan is to take a look at your personal data use over the past few months. This is easily accessible in your phone’s settings, and will make it clear if you’re better off opting for a cheaper plan with a lower data allowance.
Hotspotting with an unlimited data SIM
Sharing your phone internet connection with other devices like tablets and laptops, also known as hotspotting or tethering, is an easy way to connect them when Wi-Fi is not available. Here’s what you need to know about using an unlimited data SIM to create a hotspot.
If I have unlimited data, does that mean I can hotspot without fear of being capped?
This depends on the kind of plan you have. A lot of unlimited data SIM plans are split into two allowances: between data used on your smartphone itself, and data used by the devices connected to that phone. For example, tethered devices may be capped at 50GB a month under a network’s fair use policy.
I have an unlimited data SIM. Can it replace my broadband connection?
In some cases, yes. Hotspotting off an unlimited data plan is a viable solution if you’re living somewhere temporarily, or struggle to connect to Wi-Fi. However in the longer term, an unlimited data SIM plan may struggle to support multiple devices while maintaining a stable connection, and full-fibre modern broadband connections are likely to be much faster than most unlimited plans can offer. A 5G broadband connection, which promises an ultrafast connection without fixed cables, may be a better option.
| EE | Three | O2 | Vodafone | |
|---|---|---|---|---|
| Throttling policy | Exceeding the 600GB fair use policy will result in “traffic management” of data | No official policy in place | If you exceed the 650GB limit twice within six months, O2 may contact you about moving to another plan | Caps its unlimited customers at between 2 Mbps and 100 Mbps depending on the plan |
| Fair usage terms | 600GB fair use, up to 12 tethered devices | Truly unlimited: no data caps or fair usage policy | 650GB fair use, up to 12 tethered devices | 600GB fair use, plus speed caps on some plans |
| 4G vs 5G router | EE’s 4G router connects up to 32 devices at once, while the 5G router connects up to 64 devices | Three’s 4G router connects up to 32 devices at once, while the 5G router also connects 32 devices | O2’s TCL 4G dongle connects up to 32 devices at once, while its Nighthawk M7 Pro 5G Mobile Router connects up to 64 devices | Vodafone doesn’t sell a 4G router, while its 5G router connects up to 64 devices |
| Can it replace home broadband? | Yes: while bearing the 600GB and number of permitted device limitations in mind | Yes: although the speed and reliability of your connection may vary | No: O2 requires its unlimited data SIMs to be used in a smartphone and is not intended for home broadband use | Yes: although you’d need to be on its Unlimited Max plan to be sure of avoiding its speed caps |
| Best for hotspotting: | 2nd: EE is a solid choice but has an official fair usage policy, which Three does not | 1st: Technically, Three is best for hotspotting considering it doesn’t have any data caps or fair usage policy in place | 4th: O2 is the least flexible of the four major networks as it doesn’t allow its unlimited data SIM plans to be used as a home broadband replacement | 3rd: Vodafone has more speed caps than its rivals and doesn’t sell a 4G router |
Unlimited data SIM only deals pros and cons
Pros
- No data limit
If you opt for an unlimited data deal you can stream, download, and browse as much as you want without worrying about any extra charges.
- Flexibility
Unlimited data SIM only deals have contract lengths from one month to 36 months, giving you the choice of how long you wish to be tied to a contract.
- Speed
Unlimited data SIMs often provide faster internet speeds—sometimes even outperforming Wi-Fi! If your device lags when connected to a router, switching to unlimited data can ensure a smoother, more reliable connection.
- Unlimited texts and minutes
An unlimited data sim almost always comes with unlimited minutes and texts as well.
Cons
- Costly
An unlimited data SIM only deal often comes at a high price, and if you don't use it regularly, you will be overpaying for your data usage.
- Fair usage limits
Many mobile plans include a “subject to fair use” policy. While 'unlimited' suggests unrestricted access, some plans come with limitations. Examples include your SIM not supporting multiple devices, or speeds could be reduced after heavy usage. Always review the terms and conditions before choosing a plan—especially if unlimited data is a priority.
Which providers offer unlimited data deals?
Unlimited data SIM only deals usually cost more than deals with a set amount of data. However, you can still find a deal that suits your budget by comparing offers from a wide range of mobile networks, such as giffgaff, SMARTY, Three and more.
How to get cheap unlimited data deals?
The cost of unlimited data SIM plans varies depending on the deal you choose. 5G plans are generally pricier than their 4G counterparts—but that’s not always the case.
Consider your typical usage to determine if an unlimited data plan is worth it. Have you frequently run out of data and needed to pay for more? Comparing those costs with an unlimited plan can help you decide if the switch makes financial sense.
It’s also worth checking if your provider has a mid-contract price rise. From 2025, Ofcom banned inflation-linked price hikes for new customers. Instead, providers must disclose a fixed yearly increase upfront when you sign up. Surprisingly, around a third of mobile customers aren’t aware whether their provider can hike prices during their contract. Your price will also depend on whether you’re taking out a new phone contract or opting for a SIM only plan for your current device.
Contract Length
When choosing an unlimited data SIM plan, decide whether you’d prefer a flexible rolling contract or are happy committing to a longer-term deal.
At Uswitch, we compare a range of unlimited SIM-only plans as well as phone contracts, offering different contract lengths to match your needs:
- One-month contract – These pay as you go SIM only plans offer maximum flexibility, letting you switch providers after just a month. If you’re happy with your provider, your contract rolls on. However, this flexibility often comes at a slightly higher cost.
- 12-month contract – While less flexible than a rolling monthly plan, a one-year contract typically offers better value, rewarding you with lower prices in exchange for a longer commitment.
- 24-month contract—Often part of a phone plan but available for SIM only deals, these contracts provide the best savings but the least flexibility. If you leave early, you could pay a cancellation fee if a better deal appears during your term.
What are the benefits of unlimited data deals?
The main benefit of an unlimited data deal is that it never runs out of mobile data. So, even if you’re miles away from a Wi-Fi connection, you won’t have to worry about using a lots of data to stream a show or run an online playlist all day. It’s the best way to ensure you always have data when needed.
If you regularly exceed 20GB, an unlimited plan could be worth it. Some providers offer data calculators to help estimate your needs based on your browsing and streaming habits.
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 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
A pay as you go (PAYG) SIM card is ideal if you don’t want to sign up for a long-term contract, or you’re not keen on going through a credit check.
No credit check SIMs
No credit history? No problem, get a great value SIM only plan with no credit check and no contract.
30-day SIM deals
A 30-day or one-month SIM only deal works the same as a 12-month and 24-month SIM only deal – you’re just tied to the contract for a considerably shorter period.
5G SIM deals
5G is the next generation of smartphone technology. Now well into its rollout, there are a huge range of exciting 5G smartphones already available.
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.
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.
To receive your PAC code, text PAC to 65075. Then, give this to your new network, which will 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.
Written by Archie Burkinshaw, Content Editor
FAQs
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.
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.
Can I get unlimited 5G data?
Yes, most networks now include 5G as standard with their SIM only deals, including on unlimited data plans.
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.
If I have unlimited data, do I need Wi-Fi?
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.
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.
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.