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16 February 2021

Best and worst UK mobile networks

Want to switch mobile phone provider but don't know where to start? Our latest satisfaction survey results will help you make the right choice.
Best mobile networks 439289
Hamse Yusuf

With people using their mobile phones more than ever, having a good mobile network with a reliable signal, good speeds and quality customer service has never been more important.

At Which?, we regularly survey customers of the biggest mobile phone networks and our detailed analysis of different aspects of a mobile networks service, including their customer service and the value for money allow us to tell you what networks to avoid and what networks to go for.

Compare mobile phone contract and Sim-only plans and find out how much you could save.

Which mobile phone network is the best?

In our latest satisfaction survey, we spoke with more than 4,000 customers of 13 of the biggest contract, Sim-only and pay-as-you-go (PAYG) providers, including EE, O2, Vodafone and Three

Four phone companies did so well that we've made them Which? Recommended Providers. The names may surprise you, but all five offer good deals and great service.

Our survey reveals:

  • Which mobile phone networks were rated as Which? Recommended Providers.
  • Quotes from real customers on their experiences.
  • A look at each network's UK coverage.
  • Each provider's deals and incentives.

Mobile phone provider satisfaction survey results

Which? members have full access to the information in the table below. Join Which? to unlock the table.

Provider WRP* Customer service Ease of contacting Network reliability Value for money Customer score
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Table notes: Results based on an online survey of 4,027 members of the public in February and March 2020. Customer score is based on satisfaction and likelihood to recommend. Customers also rated aspects of service; these are presented as star ratings. Sample sizes are in brackets; we need 40 to include a survey result. *Which? Recommended Providers (WRPs) needed to receive a customer score of 75% or more,offer prices lower or equal to market averages for a typical user, and are required to move bundled customers on to the equivalent airtime/Sim-only deal when they are out of contract, to ensure customers are not overpaying.

What makes a Which? Recommended Provider?

In order to be a Which? Recommended Provider (WRP), mobile networks have to offer more than just great service to customers.

This year, we changed how we calculate WRPs in our survey and now also take cost into account. Any providers with prices costlier than market averages cannot be WRPs, even if they have a great customer score.

Who are the biggest UK mobile networks?

In the UK, there are four major mobile providers, all of whom are household names when it comes to mobile networks.

  • EE – Born out of the merger between T-Mobile and Orange, and now owned by BT, this telecoms giant is the largest with around 32 million customers.
  • O2 – Just behind EE is O2, which is owned by Telefonica, a Spanish telecoms company and has around 24 million customers.
  • Vodafone – Despite dominating the telecoms market in other countries, Vodafone is third in the UK with around 17.5 million customers.
  • Three – Owned by a Hong Kong-based conglomerate, Three is the last of the big four networks with approximately 9.9 million customers in the UK.

These four networks, often called the ‘big four’, are the only ones which own slices of the UK mobile spectrum (which is the physical signal your phone receives) and, as such, other providers have to partner with one of these four mobile networks and use their signal to power their Sims, a practice known as ‘piggybacking’.

Who powers mobile networks such as GiffGaff and Tesco Mobile?

Because the big four mobile networks have a monopoly on the mobile spectrum, other networks have to partner with one of these networks to power their Sims. Providers such as these are called MVNOs (Mobile Virtual Network Operators) and examples of MVNOs include Asda Mobile and Plusnet Mobile. Our table below shows you which of the major mobile networks power some of the largest MVNO’s.

Asda Mobile review

Asda Mobile is a PAYG-bundle only provider, offering a variety of top-up bundles. This means you can’t get contracts or Sim-only deals, and you have to pay upfront to use its services. However, it’s one of the cheaper providers out there, with prices starting from just £5 and many customers appreciate the low-cost deals Asda Mobile offers.

Find out how customers rated its service in our Asda Mobile review.

BT Mobile review

After returning to the mobile market in 2015 after acquiring EE, BT Mobile is still finding its feet in the mobile market. BT Mobile offers both contract and Sim-only deals to its customers, with BT broadband customers receiving an extra £5 off a month.

Ofcom noted that BT Mobile had higher than average complaints in their most recent analysis of results.

Find out how customers rated its service in our BT Mobile review.

EE mobile review

Born out of the merger between T-Mobile and Orange, and now owned by BT, telecoms giant EE is now the largest mobile phone provider in the UK. It offers a range of contract, sim-only and PAYG deals, with prices starting at around £5 for PAYG packs and £14 for Sim-only deals.

EE customers also get free access to the BT Sport app for the first three months and Apple Music free for six months when you take out a pay-monthly deal, whether Sim-only or contract.

Find out how customers rated its service in our EE mobile review.

GiffGaff mobile review

GiffGaff has been around for almost 10 years now and has firmly established itself in the mobile network market as a low-cost, no-frills network.

GiffGaff mainly offer 30-day Sim-only plans called ‘goodybags’, which start at £5, and some of the lowest PAYG rates available.

Part of the reason costs are kept so low is that there is no customer service call centre and all non account-related issues have to be raised in the GiffGaff community, where other customers help answer your questions (there are also chat agents for specific account-related issues).

Find out how customers rated its service in our GiffGaff mobile review.

iD Mobile review

Carphone Warehouse-owned iD Mobile is powered by the Three network and is another low-cost mobile provider, currently boasting one of the cheapest Sim-only deals in the UK at just £4 per month.

All Sim plans are on a rolling 30-day contract. This means that there are no 12-month packages available, which is a bonus for those who don’t want to commit to one mobile network provider for a long time.

iD Mobile customers can also get a contract phone with some of the latest iPhones and Samsung Galaxys available due to iD Mobile’s partnership with Carphone Warehouse.

Find out how iD Mobile customers rated its service in our iD Mobile review.

O2 mobile review

Another of the big four companies, O2 offer a large range of deals and can give customers the latest smartphones available on the market.

Refresh deals split the cost of the smartphone and airtime, meaning that you never overpay for your contract once it has finished. Also, O2's Refresh allows you to control every aspect of the deal, including length, data allowance and upfront cost.

The Priority app also allows O2 customers exclusive access to special deals, freebies and concert tickets before anyone else.

Find out how customers rated its service in our O2 mobile review.

Plusnet Mobile review

Despite being traditionally known as a broadband provider, BT’s ownership of Plusnet means that Plusnet is also able to offer mobile services to its customers.

Although not a major player in the mobile network market, Plusnet still offer inexpensive Sim-only deals, which last 30 days and are flexible, meaning you can change your package easily, depending on your needs.

If you’re a Plusnet broadband customer, you’re able to get a data boost of up to two times, depending on the package you choose.

Find out how customers rated its service in our Plusnet mobile review.

Sky Mobile review

Telecoms giant Sky went live with its mobile offering in 2017, using the O2 network to power its service. Unusually, data is charged separately from calls and texts, with prices starting from £6 for 1GB of data. Sky Mobile only offers unlimited calls and texts free for all customers.

Sky TV customers can get the best deals here, with unlimited streaming available if you have a Sky TV package.

Find out how customers rated its service in our Sky Mobile review.

Tesco Mobile review

Although Tesco is best known for being the biggest supermarket chain in the UK, Tesco Mobile has grown its base to more than five million customers and has become a real contender in the mobile network market, offering some good deals to customers.

Offering the lot in terms of contract phones, Sim-only and PAYG plans, Tesco Mobile’s plans are fairly inexpensive with Sim-only packages starting at £7.50 per month.

Tesco Mobile customers can also collect Clubcard points with its packages and use them in store or redeem them for vouchers to spend on special rewards.

Find out how customers rated its service in our Tesco Mobile review.

Three (3) mobile review

The smallest of the big four mobile networks, Three is known for offering data heavy deals for low prices.

Prices for Sim-only plans start at around £11 and come with Go Roam, which allows you to call and text the UK as well as use up to 15GB of your allowance in more than 70 countries, including Australia and the US, depending on the package you select.

Three is also unique in having ‘Go Binge’, which allows you to infinitely use data on a selected range of apps on selected packages. The apps eligible for Go Binge are:

  • Snapchat
  • Netflix
  • TVPlayer
  • Apple Music
  • Deezer
  • SoundCloud

To use Go Binge, you must have a mobile Sim plan that is more than 12GB, which currently costs £14 per month and isn’t on the cheap side.

Find out how customers rated its service in our Three mobile review.

Utility Warehouse mobile review

Utility Warehouse Mobile is a Sim-only provider who styles itself as the ‘biggest mobile provider you have never heard of’ not having any shops or engaging in any direct marketing. Utility Warehouse Mobile offer five Sim-only packages, which start at £10 for 1GB of data.

Utility Warehouse Mobile also offers mobile handsets on a two-year contract from as low as £1 per month, although this is a charge for the handset only and does not include a Sim plan. Utility Warehouse offer discounts to those customers who take out multiple utilities (broadband and energy, for example), also offering extra data as an added incentive to bundle your services.

Find out how customers rated its service in our Utility Warehouse mobile review.

Virgin Mobile review

As the world's first mobile virtual network operator (MVNO), Virgin Mobile have been offering mobile services for almost 20 years and uses EE network to power its mobile service.

Now under the Virgin Media umbrella, Virgin Mobile attempts to compete with the big players by offering the latest contract smartphones and Sim-only deals. Virgin Mobile customers also have the ability to use WhatsApp, Facebook Messenger and Twitter in the UK, and not use up any of their allowance, although voice and video calls through WhatsApp and Facebook Messenger are excluded

Find out how customers rated its service in our Virgin Mobile review.

Vodafone mobile review

Another of the four mobile giants, Vodafone has been offering its services for more than 30 years in the UK and has its own network in which to do so.

Vodafone customers can access a host of different deals with prices for Sim-only starting at around £11 on a 24-month contract. Vodafone also has Pay-as-you-go bundles starting from £10 for 3GB data, 250 minutes and unlimited texts.

Vodafone also boasts more than 75 destinations where you can roam free of charge, including the Australia, Canada and the US, more than any other UK network. Although, this is only available on the more expensive tariffs.

Find out how customers rated its service in our Vodafone mobile review.

Recommendations you can trust

Which? is independent – we work for you, the consumer, so you can be sure that our recommendations are only influenced by our test and survey results. We don't take advertising and we buy all the products that we test ourselves.