It had a combined score of 78% and was named a Which? recommended provider for the sixth year in a row, the only firm to receive the award.

Meanwhile, Scottish Power was at the bottom of the table, with the lowest average score of 51%.

It comes at a time when the energy market has seen big changes with prices soaring and many small suppliers going bust.

If the Energy Price Guarantee wasn’t currently in place, energy bills would have hit more than £4,000 by now. Yet with average bills at £2,500, and rising to £3,000 in April, many people are still struggling to pay.

The survey of 10,197 people took place in October. Energy providers were given two scores, one from customers and one from in-depth analysis by the consumer champion, and then a total overall score.

The average score customers gave to energy providers was 54%, a fall from 59% in 2022 and 64% in 2021.

A fifth of energy customers said they were moved to their current supplier when their last one failed, and 45% of those were customers of Shell Energy.

The best energy firms

Of the 15 providers included, Octopus, which took on 1.5 million Bulb customers in December, was the only firm to receive a five-star rating in any category. Customers awarded it five stars for usefulness of information about energy costs, while in every other category it received four stars.

Almost nine out of 10 (87%) Octopus customers also said they would recommend it to others.

Greg Jackson, CEO of Octopus Energy Group, said: “It’s never been more important for energy companies to look after customers.

“No company is perfect, but Which? make it clear that Octopus really is doing so much more than the old Big 6. But we’re not complacent – we’ll keep striving to improve and redouble our efforts to help people through the energy crisis.”

In second place was Utilita with a combined score of 67%. In the group’s assessment of supplier practices, it received 75% while customers gave it a score of 59%.

Third place went to Utility Warehouse, with a combined score of 65% – 64% from Which? and a 67% customer score.

Of the energy giants, EDF Energy came in seventh place, with an overall score of 62% and British Gas came in ninth, with an overall score of 60%. Challenger firms Bulb and OVO received overall scores of 63%.

The worst energy firms

Scottish Power was voted as the worst energy provider with an overall score of 51%. It received 53% in the Which? assessment of supplier practices, and a score of 49% from customers.

It received two out of five stars for the following categories: customer service, clarity of statements, usefulness of information about energy costs, and value for money.

Eon Next, which took on Npower’s customers in 2019, was in the second-worst spot with an overall score of 57%, followed by SSE Energy Services, So Energy and Shell Energy, all with a combined score of 58%.

For customer scores, SSE Energy Services scored the lowest followed by Shell Energy, with scores of 46% and 48% respectively.

SSE Energy Services only got one star for three of the aspects in Which?’s customer satisfaction survey, including the clarity of its communication about the energy market, and two stars for the remaining two. Over half (54%) of SSE Energy Services customers complained about an issue with their bill.

A ScottishPower spokesperson said: “While we’re pleased to see the survey recognising the improvements made in our customer service and payment accuracy scores, we’re disappointed that it fails to recognise the extensive support and advice we’ve provided to customers during the cost of living crisis, our best practice activities for vulnerable customers, as well as our award-winning customer app.”

A number of suppliers, including M&S Energy, Outfox the Market, Ecotricity, and Good Energy weren’t given an overall score because not enough customers responded to the questions about them. The provider E did not return the consumer group’s questionnaire so also did not get an overall score.

‘Some firms falling far short of meeting customer needs’

Rocio Concha, Which? director of policy and advocacy, said: “While customers are choosing to stay put due to a lack of deals in the energy market, our research has found that some firms are falling far short of meeting their customers’ needs during the cost-of-living crisis.

“Providers must make it as easy as possible for customers to get in touch and seek support when they need it – or customers will vote with their feet and switch away when this becomes an option.”