Three finishes bottom of the pile in Which?’s best and worst mobile phone provider survey

The consumer champion’s latest research is based on a survey of 3,739 customers in January 2024. Customer score was based on satisfaction and likelihood to recommend and people also rated aspects of service such as value for money and network speeds. 

Which?’s research suggests consumers could be better off choosing one of the smaller mobile providers that piggyback on the infrastructure of a parent network as they performed exceptionally well and a lot of these companies also shun the unpredictable inflation-linked price hikes which the Big Four have been using for years.

Three scored 60 per cent and plummeted to the bottom of the table, dropping from a 66 per cent rating last year. The smallest of the Big Four networks, it received only two stars in all categories.

Nearly half (46%) of Three customers reported having a problem in the past 12 months. This compares poorly to top-performing networks such as iD Mobile and Tesco, where only 11 per and 12 per cent of customers had issues.

Vodafone scored 68 per cent. It received just two stars for the incentives and rewards it offers but was rated four stars for network reliability. 

A possible upcoming merger between Vodafone and Three is likely to reduce competitive pressure in the market and could lead to higher prices and lower quality for consumers - at least in the short term. The Competition and Markets Authority’s investigation into the merger must thoroughly assess the implications to determine whether it will be harmful to consumers.

O2, which scored 68 per cent, is the only network to still use the outdated and arguably inaccurate inflation metric RPI, plus 3.9%, to work out its yearly price increases. This year RPI is 0.9% higher than CPI (last year it was 2.9% higher) and has meant O2 customers experiencing 8.8% hikes this year. O2 has noted that some customers, who took out their contracts prior to March 2021, pay increases which are RPI-only without the 3.9% added on.

O2’s incentives and rewards as well as its technical support rating dipped to two stars, but all other scores remained at three stars.

EE scored 69 per cent. The UK network with the most customers returned a solid but unspectacular result. A mixture of two-star and three-star ratings showed that customers were not hugely impressed – its main highlight being a four-star rating for network  reliability. 

At the top end of the table, a running theme was providers offering excellent value for money. All but one of Which?’s Recommended or Great Value providers got five stars for this metric. 

Tesco Mobile received the highest customer score of 83 per cent but was not a Which? Recommended Provider because customers that are not signed up to one of its Clubcard-connected plans face inflation-based mid-contract price increases.

Smarty scored 82 per cent. Almost two thirds of Smarty customers rated it as excellent value for money. Smarty is owned by Three – rated as the worst provider in the survey – and uses its mobile network. 

GiffGaff scored 80 per cent, and is a strong option to consider, while Voxi, 77 per cent, iD Mobile, 77 per cent, and Lebara, 76 per cent, all performed well.   

The Big Four mobile providers all performed poorly for value for money, which could be partly linked to their use of unpredictable mid-contract price hikes. EE has already recently put a stop to these hikes for new and re-contracting customers rather than waiting for Ofcom to force the company to. There is no excuse for other providers not to ditch this harmful approach.  

Ofcom needs to stick to its proposed timeline for implementing a ban on unpredictable mid-contract price rises, and ensure there are no delays, to prevent more consumers being stung with these unpredictable increases.

Which?’s latest research shows that if people are unhappy with their current provider, there are some really good options out there for saving money and getting better customer service. 

Natalie Hitchins, Which? Head of Home Products and Services, said:

“Our latest annual mobile provider survey has seen smaller firms triumphing over the Big Four and being commended for their excellent value for money. 

“Consumers unhappy with their current provider should consider switching, which is easy to do, and can save them money and improve their customer experience.

“When it comes to the unpredictable mid-contract price hikes used by a lot of the major telecoms firms, the writing is on the wall and they should put an end to this practice immediately rather than kicking the can down the road and allowing more customers to face unfair and unpredictable price increases.”

Notes to editors 

• Which? Compare: Consumers can compare mobile deals and switch to a new deal by visiting: mobilephones.which.co.uk
• Which?’s results are based on a survey of 3,739 customers in January 2024. Customer score is based on satisfaction and likelihood to recommend. Customers also rated aspects of service; these are presented as star ratings. 

Which? advice on saving money on mobile phone deals

• Sim-only deals often work out cheaper than contracts where you pay off the cost of the phone over a number of years as you risk overpaying for a Sim as part of the deal and being hit by multiple price increases across the duration. If it is too much to pay for a new phone up front, some providers offer interest-free handset repayments, or you could take out a 0% credit card. Then you can shop around for cheap Sim-only deals. 
• Think about how much data you need. Nearly half of respondents in Which?’s survey have a Sim with 20GB of data or more, yet only 13 per cent of customers say they use more than that. Another benefit to rolling monthly Sim-only deals is that you can swap and shop around on a monthly basis if your needs change – with prices starting from as little as £5. Data roaming costs abroad are also worth considering. 
• Check if the provider does unpredictable mid-contract price hikes. Until Ofcom confirms and implements its ban on unpredictable mid-contract price hikes, consumers can still end up signing long contracts which still allow this practice so it's worth checking if the provider still does this. None of Which?’s Recommended Providers indulge in this practice.  

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.

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