Thanks to widespread 4G and 5G coverage, you can use your mobile data for various data-intensive online activities such as UHD streaming and gaming. But, with data caps, you may not be able to finish watching your favourite show or end up paying loads for using too much data.

Luckily there’s a solution! Unlimited data. We have created a detailed guide with the best unlimited data SIM-only deals to help you find the right plan if you are a regular internet user like us!

List of unlimited data SIM-only deals


What are unlimited data SIMs?

Unlimited data SIMs enable you to use the internet without worrying about data restrictions. With these SIMs, you don’t pay based on how much data you use. You only pay a fixed rate which covers you for all your internet use for a fixed amount of time, usually a month.

There are two main types of unlimited data SIM deals: pay-as-you-go and bill pay. With pay-as-you-go, there are no long-term contracts, so you can cancel or switch networks anytime without any extra fees. Unlimited data bill pay plans are typically cheaper, but you have to commit to that particular network for a certain amount of time.

Compared to mobile phone deals with limited data plans, unlimited data deals are generally more expensive. However, if you’re a heavy mobile internet user, using an unlimited data deal means you can avoid overage charges and save money.

How do unlimited data SIMs work?

Unlimited data SIMs work like any other SIM. Once you’ve signed up and paid, the network activates your SIM. You can then insert the activated SIM into your phone and switch your mobile data on for instant internet access.

No matter how much internet you use, there are no extra fees with truly unlimited data SIMs. However, certain unlimited data SIMs aren’t really unlimited and have a few restrictions. For example, some networks limit your speed, cap video quality, or prioritise higher-paying subscribers to prevent excessive use.

Some unlimited data SIMs have data limits. These limits are generally quite high so most users won’t ever reach these caps. With most UK unlimited data deals, you get at least 650GB a month.

But the very best UK unlimited data deals are truly unlimited with no data caps, speed limitations, or any other catches!

Benefits of unlimited data

Sign up for one of the best unlimited data SIM-only deals and enjoy the following benefits:

  • No way of running out of data
  • Significant savings for heavy data users
  • Unlimited internet on any device with a mobile WiFi hotspot
  • 4G coverage in 99% of the UK with most major networks
  • No surprisingly high bills at the end of the month
  • Easier budgeting with simplistic deals
  • No credit checks with the pay-as-you-go unlimited data plans
  • Limitless UHD streaming with no fees based on usage
  • A huge selection of short-term contract options to choose from

Which networks offer unlimited data SIMs?

When it comes to unlimited data SIMs in the UK there’s a lot to choose from. Let’s take a look at some of the best mobile network providers with limitless data deals.


Vodafone is a leading UK network provider. It has a range of unlimited data SIM-only deals with both 4G and 5G options on as little as a 30-day contract.

This network provider is a popular pick amongst frequent travellers, thanks to its unlimited roaming plans for 80+ countries!


O2 is the most popular UK mobile network with extensive 4G and 5G coverage. It offers excellent value for money on its unlimited SIM-only plans, especially on a 12-month contract.

Some O2 plans include extra perks such as free streaming subscriptions, phone upgrades, and even broadband boosts.


EE has excellent 4G and 5G coverage. It has SIM-only deals with unlimited UK calls and texts as well as data!

Unlike some other UK networks, EE’s truly unlimited data offer doesn’t have a speed cap. So, it’s perfect for UHD streaming, downloading, and reliable WiFi hotspotting!

Tesco Mobile

Tesco Mobile uses O2’s network in the UK to offer brilliant 4G and 5G coverage. Supported by Tesco, one of the largest supermarket chains in the UK, it offers affordable SIM-only deals including unlimited data.

With no EU roaming charges on its unlimited data plans until 2025, it’s a great choice for frequent travellers!

Pros and cons of SIM-only unlimited data deals

If you are thinking of getting an unlimited data SIM-only deal, then you should consider the following benefits and drawbacks of such deals:

How to find the best unlimited data deal

To find one of the best unlimited data SIM-only deals, consider the following:

  • Contract length. Pick a short contract if you want maximum flexibility or a longer term for the lowest prices. One-month, 12-month, and 24-month contracts are all possibilities (depending on the provider).
  • Unlimited social data. Consider a plan with unlimited social data, if you only need data for social media. Deals with unlimited data exclusively for social media often cost less than completely limitless data plans.
  • Freebies. Keep an eye out for rewards and incentives. Free streaming subscriptions, WiFi hotspots, bundle discounts, and broadband boosts are just some of the perks you might find.
  • Calls and texts. Take note of how many call minutes and texts you use each month. Some unlimited data plans include unlimited UK calls and texts. Others have a limited amount or none at all. Get a bundle that, at minimum, meets your current needs.
  • Roaming. Having an unlimited data plan doesn’t necessarily mean you get unlimited data overseas. Look for a deal with unlimited roaming too if you’re a frequent traveller.
  • Price. Make a list in order of importance with everything you want from your SIM-only plan. Find all the plans that match and compare the prices to find the best value offer. You might need to sacrifice some of your less important wants if nothing meets your budget.

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

Yes, you might temporarily lose service when you switch to a SIM-only deal with another network.

Once you successfully switch, your old network immediately cancels your account along with any services associated with it.

The network you’ve chosen to switch to won’t necessarily activate your SIM-only deal straight away. UK SIMs can take up to 24 hours to activate and that’s not including delivery if you’re not picking up the SIM in the store.

The time between your current network cancellation and your new network's activation is how long you lose service. However, you can completely avoid service downtime, if you don’t need the same number for your new deal. Just keep your old network account active and only cancel it once your new SIM-only deal is active.

How easy is it to switch networks?

It’s usually quite easy to switch networks if you have chosen one of your favorite unlimited data SIM-only deals.

Firstly, check you’re eligible for a switch. If you’re currently on bill pay, you might have to pay a cancellation fee. When switching to a SIM-only deal, you also need an unlocked phone to use with your new SIM.

To switch networks and keep your current number, you have to get your PAC number. The easiest way to acquire this is by texting “PAC” to 65075 or by calling your current network's customer service team. Then, just give the PAC number to the network you want to switch to.

If you don’t need to keep your number, it’s even easier. Open a new account with your desired network. Then reach out to your old network and cancel your account.

Alternatives to unlimited data SIM deals

If you’re not a heavy mobile internet user, you might not need to get an unlimited data deal. Here are some alternatives to unlimited data SIM-only deals:

  • Regular SIM-only deals: For users who are looking for affordable bundles that include a high number of minutes, texts, and data
  • Pay-as-you-go plans: Ideal if you don’t have a lot of data needs because you only pay for what you use
  • 5G SIM-only offers: For those looking for the best mobile internet speeds with reasonable data caps and fair prices