Britain's smallest energy suppliers have come up top in a poll of the best firms for overall customer satisfaction and service.

Octopus, which supplies more than 400,000 homes, was given a 'good' to 'excellent' rating for value for money by nine in 10 customers who gave it an 80% score for customer service.

It compared to SSE - the highest scorer of the 'big six' - which received four-star ratings but only a 58% satisfaction score for customer service.

Consumer group Which? surveyed 8,000 people across the UK about their provider - based on value for money, customer service and accurate billing.

Despite the collapse of firms such as Spark Energy and Economy Energy in recent months, it found small firms dominated the rankings outstripping the entire big six market.

Top 5 firms for customer service

  1. Octopus Energy
  2. Robin Hood Energy
  3. So Energy
  4. Ebico
  5. Tonik Energy

Octopus Energy was followed by Robin Hood Energy and So Energy in joint second place, and Ebico and Tonik Energy in joint fourth position.

However, small supplier, Solarplicity, rated for the first time in the Which? survey, was the worst energy firm according to its customers, with an overall customer score of just 44% (compared with Octopus’ 80%).

Best customer service

Source: Which?

It was the only provider to receive one-star ratings, including for customer service, both online and on the phone. Additionally, three quarters of its customers said that it is poor or very poor at dealing with complaints.

Elsewhere, the Big Six energy suppliers - British Gas, EDF Energy, Eon, Npower, Scottish Power and SSE all fell to the bottom third of the table, with not one receiving an overall customer score higher than 58%, 22 percentage points lower than Octopus.

Worst 5 firms for customer service

  1. Solarplicity
  2. Spark Energy
  3. Scottish Power
  4. Npower
  5. British Gas

SSE was the highest-ranked of them - and the only one to receive four-star ratings for its customer service online and on the phone. Npower and Scottish Power were joint lowest of the Big Six and were the only two to receive two-star ratings for their handling of complaints.

Overall, Which? found less than one in five (18%) Big Six customers are very satisfied with their supplier, compared to a third (33%) of customers with medium and small suppliers.

Three small firms included in the Which? survey - Spark Energy, Extra Energy and Economy Energy - have ceased trading since the survey was conducted.

Worst customer service

Source: Which?

All performed poorly in the consumer champion’s survey. Spark Energy is second from last, in 29th position. Extra Energy would have been in joint 26th position alongside British Gas, while Economy Energy would have been in 29th position.

Alex Neill at Which? said: "Our survey shows the importance of value for money and good customer service - energy suppliers delivering both to their customers tend to be thriving, while the Big Six and other poorly-ranked firms are paying the price for not giving customers what they want.

Video Loading

"All energy companies should be working to give their customers competitive prices and excellent customer service. If you’re not getting a good deal, you should look to switch, as you could potentially save over a hundred pounds and get a much improved service."

Rachel Reeves MP, chair of the Business, Energy and Industrial Strategy Committee, said: "The Which? survey highlights once again that the Big Six are miserably failing their customers. 

She added: "Customers should continue to shop around because they cannot rely on energy suppliers giving consumers a good deal or delivering the quality customer service which they deserve."

The figures come at the start of "Big Energy Saving Week" - an initiative run by Citizens Advice and the Department for Business, Energy and Industrial Strategy.

Today's figures follow a record high in the number of people switching and ditching their energy supplier in search of better deals elsewhere.

Energy UK said more than 1.7 million households have switched to small and medium sized energy providers - shunning the "Big Six".

One in five customers switched their energy provider in 2018 - an increase of 6% on the previous year.

For help on how to find a cheaper deal, see our guide on how to switch your energy supplier.

If you're wondering if it's cheaper to leave the heating on all day over winter, see what the experts say, here.