Biggest mobile providers outshone by smaller rivals, Which? reveals 

The UK’s biggest mobile providers have fallen short on value for money and are being outperformed by smaller rivals who piggyback on their networks, according to Which?’s annual customer satisfaction survey.  

During the pandemic, more people than ever have turned to their phones and technology as a way to keep in touch with family and friends.

The Big Four mobile providers – O2, EE, Vodafone and Three – serve nearly nine in 10 UK customers.

However, in Which?’s annual customer satisfaction survey, smaller providers that use the Big Four’s networks managed to outdo them across the board – including on value for money, customer service and network reliability.

O2 scored the highest of the Big Four providers and earned joint fifth place out of 15 providers, alongside Utility Warehouse.

It received a high rating for ease of contact, but its customers considered it below average for value for money. Only a quarter (23%) rated it as being ‘excellent’ in this area.

However, GiffGaff, Tesco Mobile and Sky Mobile, which all piggyback on O2’s network, triumphed over their larger rival in Which? rankings. GiffGaff came in first place and earned strong ratings in several categories with 91 per cent of customers saying they’d recommend it to a friend.

Tesco Mobile came in joint second place with Sky Mobile and SMARTY. Both Sky Mobile and Tesco Mobile scored higher than O2 on value for money – an area all of the Big Four providers fell short on in our survey.

EE and Vodafone came in the bottom half of the rankings. Both EE and Vodafone performed poorly on value for money. This is perhaps unsurprising given that 7 per cent of their customers received incorrect or unexpectedly high bills – the highest across all the providers.

Three earned the lowest score of the Big Four providers. Value for money and network reliability were key weak points for Three.

Three customers were the most likely to experience network outages lasting more than one whole day (8%) and one in ten (10%) experienced unexpected or unreasonable price hikes.

One Three customer responding to Which?’s survey said that a universal change in tariff had made it more expensive for them to use the provider despite having a substantial balance to use up.

Like O2, Three was beaten by a smaller operator using its network. SMARTY is owned by Three and is a new entrant to Which?’s survey at joint second place.

The highest-scoring mobile providers are eligible for Which? Recommended Provider (WRP) status, which also requires providers to offer reasonably priced contract deals, including Sim-only.

Ofcom now requires all providers to notify customers when their telecoms contracts come to an end. Which? encourages consumers to compare the deals available when their contract comes to end – even if they’re planning to stay with their current provider – to ensure they aren’t overpaying.

Rocio Concha, Director of Policy and Advocacy at Which?, said:

“Our research found that the biggest mobile providers are being outshone by their smaller rivals.

“A provider should not only give you good network reliability but also value for money and customer support when you need it.

“If customers are out of contract but happy with the service they’re receiving, they should try negotiating a new deal but if all else fails it might be time to switch.”


Notes to editors

Which? surveyed 4,050 UK adults with a mobile phone between 29th January and 15th February 2021. Fieldwork was carried out online by Savanta and data includes nationally representative sample plus a provider boost.

Read more about Which?’s mobile switching service:

About Which?

Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation we’re not for profit and all for making consumers more powerful.

The information in this press release is for editorial use by journalists and media outlets only. Any business seeking to reproduce information in this release should contact the Which? Endorsement Scheme team at

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