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Best and worst energy companies

Which? energy survey results

By Sarah Ingrams

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Which? energy survey results

Frustrated with your energy firm? Find out what thousands of energy customers think of their suppliers. Use our research to choose the best energy company for you.

Electricity and gas are essential services, but that doesn’t mean you should put up with poor service or high prices.

Our annual UK energy satisfaction survey covers 30 suppliers in Great Britain six in Northern Ireland, and captures the experiences of 8,000 energy customers who tell us what they really think of the service they receive. This gives you a unique guide to finding the very best energy companies you can rely on and avoiding those you can't.

As well as rating the 'Big Six' energy suppliers - British Gas, EDF Energy, Eon, Npower, SSE and Scottish Power - we also investigate smaller companies. This includes Bulb Energy, Co-operative Energy, First Utility, Octopus Energy, Ovo Energy and Utility Warehouse.

Just one energy company earned our prestigious Which? Recommended Provider Award: Octopus Energy. Read on to see how other energy suppliers – including yours – fared. Or find out what it takes for a company to be awarded a Which? Recommended Provider for energy.

If you live in Northern Ireland, find out which are the best and worst Northern Ireland electricity and gas firms, according to their customers.

Just want to save money on your energy bills? It's quick and easy to switch energy supplier with Which? Switch, our impartial free switching site. Compare gas and electricity prices now.

Best and worst energy companies

We asked 7,429 GB energy customers to rate their energy suppliers’ customer service (both online and over the phone), how they deal with complaints, their value for money, the accuracy and clarity of bills, and whether they feel the company helps them to understand and reduce their energy use.

See the full results of our survey in the table, below. Click on each company to find out more about it. Expand the table to see the full results, including whether companies passed our pricing assessment using the link at the end.

Energy companies rated
  Company Bill accuracy Customer service (phone) Customer service (online) Complaints handling Helping you understand and reduce energy use Value for money Customer score

Octopus Energy


Robin Hood Energy

- 78%

So Energy

- 78%


- - 76%

Tonik Energy

- 76%

Ovo Energy


Utility Warehouse


Bristol Energy

- 72%

Bulb Energy






Boost Energy



- - - - 70%

Flow Energy

- 68%

Green Network Energy

- 68%

Co-operative Energy


First Utility


Green Star Energy


Avro Energy

- 64%

Sainsbury's Energy


Together Energy

- 60%



EDF Energy




iSupply Energy

- - - 57%

British Gas




Scottish Power


Spark Energy




Click here for the full survey results table

Table notes
The customer score combines customers’ overall satisfaction with their likelihood to recommend, and is not directly linked to the star ratings.
Overall average customer score: 61%. This is weighted for the market share of each energy company.
(-) indicates too few responses to give a rating.
In bold – customer scores over 70%, above average procedures and practices score and combined 2018 call waiting and complaint score.
Sample sizes: Octopus Energy (168),  Robin Hood Energy (68), So Energy (98), Ebico (45), Tonik Energy (74), Ovo Energy (433), Utility Warehouse (154), Bristol Energy (57), Bulb Energy (168), Ecotricity (75), Utilita (110), Boost Energy (65), Engie (40), Flow Energy (66), Green Network Energy (89), Co-operative Energy (135), First Utility (132), Green Star Energy (72), Avro Energy (69), Sainsbury's Energy (135), Together Energy (68), SSE (929), EDF Energy (404), Eon (5122), iSupply Energy (45), British Gas (1,002), Npower (728), Scottish Power (882), Spark Energy (79), Solarplicity (84). Economy Energy and Extra Energy have stopped trading since our survey so their results aren't included above. Economy Energy was in 29th position with a customer score or 53%. Extra Energy was in =26 position with a 56% customer score. Survey: September 2018.

Looking for our Northern Ireland results? Go to Northern Ireland electricity and gas firms.

Interpreting the Which? energy survey results

Energy companies are ordered above based on their customer score. The full survey table (click the link below the table to reveal this) also shows how the companies scored on our other criteria, including customer service, value for money and bills. Plus you can find out more about each company by heading to its individual review page. There you’ll find out how fast it responds to customers online or on the phone, along with how it compares for resolving complaints and in our procedures and practices assessment.


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Our procedures and practices assess compares companies' practices for:

  • Billing
  • Complaints
  • Customer service
  • Product management

So if great online customer service is important to you, look for a company with a full five stars; the more stars, the better.

Who's top of the Which? energy survey?

Octopus Energy tops the table this year, followed closely by Robin Hood Energy, So Energy, Ebico and Tonik Enery.

Octopus Energy is also this year’s only Which? Recommended Provider (WRP) for energy.

Robin Hood Energy missed out on WRP status because it scored below average on our performance assessment, which takes into account customer waiting times and complaints. So Energy missed out as it scored below average in our procedures and practices assessment. Ebico and Tonik Energy scored below average on both of these assessments. Find out  more about them on our Which? Recommended Provider page.

Price is the most important consideration for you when choosing a new energy supplier, according to our survey, so it’s no surprise that the highest-scoring energy companies are considered good value for money by their customers.

Price isn’t everything though – and being rated good value for money by customers doesn’t mean an energy supplier is the cheapest on the market. Renewable energy firm Ecotricity (in joint eighth position) has one of the priciest tariffs on the market. But its customers rate it good value for money, showing that it keeps them satisfied.

In fact, our survey shows the importance of customer service. Nearly half (49%) of lowest-ranked energy firm Solarplicity’s customers rated its customer service poor or very poor. Plus a third (34%) said they’d had a problem with its customer service in the last two years.

The Big Six

The biggest six energy suppliers are in the lower half of the table. Npower and Scottish Power are joint-lowest scoring among them, though not the lowest-scoring suppliers overall. This is the first time that Npower has not been the lowest-ranked company in our survey.

SSE is the highest-rated of the Big Six this year, in 22nd position. Its customer score is just four percentage points different to Npower and Scottish Power’s however, showing that customers find that there’s little to choose between them.

See our Big Six energy companies guide for full details about each firm.

Who's bottom of the Which? energy survey?

Small firm Solarplicity is the worst energy supplier in our 2019 survey, according to its customers.

Spark Energy and joint-placed Npower and Scottish Power complete the bottom three positions. Spark Energy was also in the bottom three last year. Since then it has gone bust and been bought by Ovo Energy. So we’ll be keeping an eye out to see if customers’ opinions improve.

How quickly do energy companies respond to customers?

Although you can contact most energy companies by email, live chat and social media, the majority of us still choose to pick up the phone to speak with our energy company.

We conduct snapshot undercover investigations to reveal how long customers have to wait for their phone calls to be answered by a human being. We also contacted energy suppliers via live chat (if they offered it) or email or online form (if they didn’t offer live chat) to find out how long it takes to get a response that isn’t an automated acknowledgement.

In our latest investigation in September and October 2018, we contacted energy suppliers a total of 822 times. We made 460 phone calls to 38 energy companies, sent 422 emails, online form requests and live chat messages.

Which energy companies are quickest?

Answering the phone quickly is not impossible. Affect Energy managed to answer calls to its customers services in just 10 seconds on average, making it the fastest energy supplier to put us through to a human. 

Overall there were six firms that put us through to a human in under a minute this year.

To see the full results of our 2018 investigation, read our story on energy company customer waiting times 2018, which includes how promptly companies responded to live chat and whether it’s worth emailing if you need a speedy response.

We can help you save money on your energy bills. Use our independent free switching site, Which? Switch, to find the cheapest energy deal.