Three unlimited data SIMs

By Claire Nottage | February 22nd, 2024

Three is one of the four mobile networks in the UK and was the first to offer unlimited data deals. Available on one month, 12-month and 24-month contracts, Three’s unlimited data plans are some of the cheapest such deals on the market.

Three Mobile logo

With so many mobile providers now offering unlimited data deals, you may be wondering which to choose and whether one of Three’s good value deals would be a good bet. We’ve taken a look at the details to help you decide.

Key features

Here's a quick summary of the key features when considering Three unlimited SIMs.

Prices from £25 per month
Available speeds 4G, 5G
Monthly data usage Unlimited
Roaming data usage 12GB
Contract lengths 1 month, 12 months, 24 months
Coverage 99% of UK population
Personal hotspot Yes (unlimited)

Compare Three SIM deals Visit Three

Our review

A SIM with unlimited data affords you a huge amount of online freedom. Quite simply, you will never run out of data, so you can stream and download as much as you like, wherever you are, without worrying about hitting your limit. You also won’t have to pay for a data bolt-on when you run out, or be penalised for going over your allowance. Unlimited data deals are no longer outlandishly expensive either, costing around £25 per month on average.

You can also use your mobile data as back-up if ever your home broadband service goes down, by creating a personal hotspot to get other devices online too. Three allows unlimited tethering with its unlimited data plans – ideal for keeping the kids entertained in the car or for working on a laptop on the move. Plus, as Three’s unlimited data deals are truly unlimited, you won’t have to face any kind of throttling or traffic management at any time of day.


Map of the UK

Three states that it offers 99% coverage with its 3G and 4G signals. Just bear in mind that this percentage refers to population, not geography, so even with 99% coverage, there will be blackspots around the country, but equally this does apply to all other networks as well. Three has also now established its 5G signal in almost 500 UK towns and cities. You should be able to receive a 4G signal with Three but 5G is not yet widely available, as it is concentrated more in towns and cities than rural areas.

To find out what Three signal is like in your area, you can visit Three’s coverage checker.

Check Three coverage


Three does not put any kind of speed limits on its unlimited data offerings, which means, if you can get 5G in your area, you should be able to benefit from some extremely fast download speeds indeed. Some providers advertise unlimited data deals but throttle the speed to a painfully slow 2Mbps, or even slower..

Three holds the honour of having the fastest 5G download speed of all the networks, averaging 204.3Mbps in the most recent tests carried out by Opensignal. This is considerably faster than the second fastest speed of 129.2Mbps, held by EE.

When it comes to 4G speed, Three averages 25.2Mbps, coming second place to EE, which averages 44Mbps, but ahead of both Vodafone and O2.


Three offers its customers the ability to use their UK data, calls and texts in up to 71 countries around the world. Customers travelling to the EU will have to pay £2 per day and customers travelling beyond the EU will be charged £5 per day.

Three imposes a fair usage limit of just 12GB per month when it comes to using your data abroad, and also sets a charge limit of £45 per month for customers travelling around the world. Three expects its customers to only use data abroad for short periods such as holidays or business trips. If you spend more than two complete months in a 12-month period abroad, Three will suspend your account for international use.

Since data usage abroad is severely limited, tethering abroad is not really viable, even though Three does still permit it. With only 12GB to play with, any attempt to tether your laptop to your phone would use all your data up in no time.

Extras and features

As well as its rewards app Three+, customers can enjoy a range of features and benefits when they sign up to a Three unlimited data deal.

  • Three+ – Three’s customer rewards app offers discounts on various lifestyle treats and products from restaurants and cafes, clothing, beauty, newspapers and magazines, fitness, and entertainment.
  • Unlimited Personal Hotspot – Whereas some providers limit the amount of data you can use for tethering, Three does not, so you can use your mobile data to keep your laptop online as much as you like
  • Unlimited texts – Some mobile providers claim to include unlimited texts, when in fact there is a limit of 5000 a month. Three places no limits on the amount of texts you can send at all.
  • Control your spending – Although Three’s unlimited plan comes with unlimited minutes, there are some numbers that are not included (such as 084, 087, and 0500). You can choose to block these numbers to avoid ending up with a larger bill than you planned.
  • Keep your phone number – If you want to move to Three from another network, you can bring your current number with you. Just text PAC to 67075 and give the code to Three when you order your SIM deal.

Compare Three SIM deals Visit Three


All the other UK networks (Vodafone, O2 and EE) now offer unlimited data deals, as well as a number of MVNOs (Mobile Virtual Network Operators), such as giffgaff, Smarty, Asda, ID Mobile and Virgin Mobile.

Cheapest alternatives

When it comes to price, you will struggle to find a cheaper unlimited data deal than those offered by Three, with the possible exception of ID Mobile, which also uses the Three network and does not throttle your speed.

If you aren’t too worried about getting fast 5G, and are happy with an unlimited 4G deal, then Asda Mobile offers some very cheap unlimited data deals. Running on the Vodafone network, Asda Mobile throttles 5G usage to 2Mbps, but offers truly unlimited 4G data.

Best alternatives with perks

Inevitably, the best unlimited mobile deals with extras come with a bigger price tag. O2 offers free Apple Music, free Amazon Music, free DIsney+ amongst its freebies for customers purchasing an unlimited data deal, but it costs almost double the price of the cheapest unlimited deals on the market.

Vodafone prices its unlimited data deals according to speed, meaning you will pay more for an unlimited deal with full speed 5G than you will for a speed limit of 10Mbps or 2Mbps. It offers its VeryMe rewards scheme that comes with free cinema tickets to Vue cinemas, free Costa coffee and discounts on local restaurants. Vodafone also offers its Xtras with select plans, which include free battery replacements, free picture messaging and free roaming.

EE offers customers its Smart Benefits, including free subscriptions to Netflix, Apple Music, BT Sport and Xbox Games Pass. The amount of Smart Benefits you are entitled to will depend on the unlimited data deal you choose.

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