Unlimited data SIM deals

It’s not hard to get the best value out of your smartphone. Most of us work them pretty hard – social media, watching TV, downloading music and online shopping.

But getting good value out of your mobile phone contract can be another matter. How much data do you need? And is unlimited data really a good thing?

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What is an unlimited data SIM deal?

An unlimited data deal allows you to use the internet on your mobile (or tablet) without having to worry about exceeding your data limit – and, in turn, avoiding hefty extra charges. It also means you don’t need to worry about finding somewhere with Wi-Fi to stay online anymore.

Unlimited data SIM deals include:

  • unlimited 4G or 5G data
  • unlimited minutes
  • unlimited texts.

Simply pop the SIM into your mobile or tablet, then download, text and call as much as you like. Unlimited data deals are available on pay monthly SIM only plans and pay as you go services.

Which networks do unlimited data deals?

The following networks currently offer unlimited data deals:

  • Three – Three specialise in unlimited data plans, with rolling monthly and 12-month contracts available.
  • SMARTY – offers a rolling monthly contract with unlimited data for endless browsing with added flexibility.
  • Vodafone – one of the ‘big four’ networks, Vodafone offer unlimited data on rolling monthly, 12-month, and 24-month plans.
  • ID Mobile – unlimited data available on a 12-month contract or rolling monthly plan.
  • GiffGaff – specialise in rolling monthly deals, with unlimited data plans available.
  • Voxi – exclusively offers rolling monthly contracts, with unlimited data available.
  • O2 – another of the ‘big four’ UK networks, O2 currently offer both 12-month and 18-month unlimited data plans
  • Virgin mobile – exclusive to existing customers only, Virgin mobile offers 12-month unlimited data plans.

Pros and cons of unlimited data SIMs


There are some very obvious advantages of having an unlimited data SIM:

  • You can stream, download and browse as much as you like
  • You don’t need to worry about running out of data or when your allowance resets
  • No extra charges for using data


You should be aware of any terms and conditions your provider may have in place, such as:

  • Fair usage policies
  • Tethering caps or allowance
  • Roaming data charges
  • Speed caps

Your contract should clearly stipulate if your provider has a fair usage policy and what it is. If you have any doubts about how much data you should be using, then contact your provider.

How much does unlimited data cost?

How much unlimited data SIM plans cost can vary depending on the type of deal you’re on. This is partly because the introduction of 5G has split the market, as early adopters have made the move over, while many of us are still on the slower 4G service. What probably won’t surprise you, is that 5G deals tend to be more expensive than their 4G equivalents, but that’s not always the case.

You should also check the length of the contract on offer. Rolling monthly contracts can be more expensive than their 12 and 24-month equivalents, because they offer greater flexibility. While not always the case, you can be rewarded with a cheaper deal, by locking yourself in for a longer contract. That’s something you need to decide.

Do I actually need unlimited data?

Whether you actually need unlimited data depends on your average monthly usage. Check out your data usage stats, which can be found in your phone’s settings. If you only use around 3GB over the course of a month, then paying for unlimited data perhaps isn’t worthwhile. However, if your limit is around 20GB and you find yourself exceeding this every month, then an unlimited data deal might be worth it.

To give you an idea of typical usage, the average UK customer uses about 2GB of data a month – this equates to:

Activity 2GB Equals
Internet browsing 6,000 pages
Music streaming 320 songs
Email sending 20,000 emails
WhatsApp messaging 2.5m messages
Photos uploading 8,000 photos
YouTube viewing 620 mins/10.3 hrs

What’s the best alternative to an unlimited data SIM?

If you use lots of data but don’t want a SIM only deal, a good alternative would be a handset contract that includes unlimited data too. There’s plenty of deals around, including handset deals on big names such as Apple iPhone and Samsung.

If you’re more interested in unlimited calls and texts than data, many networks also offer a higher data allowance with unlimited minutes and texts on their phone contracts. So, if you want a new phone as part of the deal and are happy with 64GB of data a month, this might work out better for you.

How to compare unlimited data plans

Whatever your data needs and budget, let us do the searching for you. Simply use our comparison service and find a deal in minutes.

To find a deal that’s right for you, simply click below and choose a mobile phone plan or SIM only plan. We’ve included a handy filter so that you can narrow down your search. Simply choose ‘unlimited data’ and you’ll get a list of all SIM deals offering unlimited data.

Here are some things to look out for when comparing phone and SIM deals. Using our comparison tool, you’ll be able to filter and sort SIM deals by:

  • Price – obviously you want the cheapest SIM deal, but that’s not all that matters
  • Text and call minutes – while you’re looking for unlimited data, make sure that you’ve got enough texts and call minutes too
  • Contract length – decide whether you want a more flexible, rolling monthly plan, or whether you’re happy to lock yourself in to a longer-term contract
  • Freebies and gifts – some deals will throw in a free gift like headphones, a games console or a voucher
  • Network – the big four networks (EE, O2, 3 and Vodafone) have almost nationwide coverage, but some smaller networks may not, so it’s worth checking.

Frequently asked questions

Can I use my unlimited data abroad?

Some providers offer data use abroad as part of their unlimited contract deals. For example, Three offers unlimited data deals including ‘Go Roam’ at no extra cost with its Advanced plans.

Other providers may restrict the limit when you go abroad, so always check the plan details before you sign up if you want unlimited data abroad.

What contracts are available for an unlimited data SIM?

If you’re looking for a good SIM deal for unlimited data, this can depend on the type of contract you’re looking for. We compare a range of SIM only unlimited plans, with a selection of contract lengths to suit your needs:

  • One-month contract – these offer the most flexibility, as they allow you to end your deal and swap to another after just a month. If you’re happy where you are, the contract simply rolls on, which means you can almost move whenever you’d like.
  • 12-month contract – while less flexible than a rolling monthly plan, these year-long contracts often reward you with a cheaper deal, for locking yourself in for longer.
  • 24-month contract – these are usually offered as part of a phone plan, but you can get these for a SIM-only deal too. Again, you can be rewarded for locking yourself in for a longer term, with a cheaper price, but you lose out on that flexibility. If a better deal comes along in a month or even a year, you won’t be able to switch without paying up.

Can I get unlimited 5G data?

Yes, 5G unlimited data plans are available, but only with some networks. The ‘big four’ (EE, O2, Three and Vodafone each offer 5G, but other smaller networks may not. This means you have fewer networks to choose from, so compare providers to find one that offers what you need.

Which company has the cheapest unlimited data plan?

The SIM market is very competitive, which means it’s easy to find a cheap deal. Although offers are always changing, SMARTY and Three tend to offer consistently cheap unlimited data deals.

Am I limited to how much data I can hotspot if I have unlimited data?

Some networks will let you hotspot as much data, on as many devices as you’d like. But, some networks will have limits, so you should check the terms and conditions of your contract, or ask your network provider.

Can you get unlimited pay-as-you-go deals?

If you don’t want to be tied to a long contract and you’re happy with your current phone, a pay-as-you-go SIM is also a good alternative.

Does my phone have to be unlocked?

If you get an unlimited SIM plan with another provider, your phone will need to be unlocked for it to accept the SIM. If you’re not sure if your phone is unlocked, ask a friend or family member if they’re on another network. If they are, try their SIM in your phone. If it works okay, it means your phone is unlocked.

If it doesn’t work, your phone could still be locked to your old network. You’ll need to contact your old provider and ask if your phone can be unlocked for other networks. Depending on the network, you may be charged a fee.

Can I keep my old number?

To keep the same number, you’ll need to contact your old network provider and request a 9-digit number PAC (Porting Authority Code). They should send the code within two working days. You won’t be able to use your old number if it’s disconnected, so make sure you get the code and change over before you cancel your old contract.

What SIM card size will I need?

The size of SIM card you’ll need will depend on your handset. There are three types of SIM:

  • standard (15x25mm)
  • micro (12x15mm)
  • nano (8.8x12.3mm)

Usually, older phones (over five years) old will have a standard SIM. Newer phones are more likely to need a micro or nano SIM.

Do I need unlimited calls and texts as well?

Popular messaging services, such as WhatsApp and Skype, let you text, phone or videocall for free using Wi-Fi or 4G. However, there will always be times when internet access is not possible, in which case, you’ll need to phone or text the traditional way.

Having unlimited minutes and texts may not be necessary for you, but most unlimited data plans will include them anyway.

Will I need a credit check to get an unlimited SIM plan?

This depends, as some of them do need a credit check, while others don’t. If you’re on a traditional 12 or 24-month contract, these will normally involve a credit check. If you’re on one of the more flexible plans, like pay as you go, or rolling monthly plans, these can offer a pre-paid service which avoids a credit check being run on you. If in doubt, it’s always best to check with the network before signing up for a plan.

Author image Holly Cox

What our expert says...

"An unlimited data deal gives you the additional benefit of being able to use your phone as a Wi-Fi hotspot. To find the right deal for you, shop around and compare unlimited deals with plans that have a large data allowance."

- Holly Cox, Digital expert

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Correct as of December, 2022.