Energy suppliers have been accused of leaving households in the lurch and offering poor customer service, just as bills soar and the cost of living crisis bites.

Customer service amongst energy companies is at a five-year low, according to charity Citizens Advice, despite the average household now paying £1,971 a year for their gas and electricity. It warned service levels had dropped “across the board” and customers faced a “trend of declining standards”.

Its quarterly rating of suppliers found Utilita, which in 2020 was found to have overcharged almost 40,000 of its prepayment customers, was the lowest rated, with a score of 1.7 out of five between October and December last year.

Boost and Ecotricity followed closely behind, with ratings of 1.88 and 2.10 out of five respectively.

Longer call waiting times had exacerbated the energy crisis, said Citizens Advice. The average customer now waits for more than five minutes on the phone, compared to around four minutes at the end of 2020.

However, customers with the poorest performing suppliers faced a wait of 15 minutes. It comes as the price cap on energy bills rose by a record-breaking £693 last week, pushing the average household payment to £1,971 a year.

Millions of households have been contacted by their supplier to notify them of huge increases to their bills. Citizens Advice warned customers could be missing out on “vital” support if they were unable to contact their supplier.

Dame Clare Moriarty, of the charity, said: “With millions of people struggling to make ends meet as the cost of living soars, it’s more important than ever that people can turn to their energy company for support.

“The drop in customer service standards comes at the worst time possible. It’s Ofgem’s job to make sure companies are delivering a good service. But the current system isn’t working.”

Even the best performing suppliers scored lower than previous years, according to the analysis by Citizens Advice. The best supplier historically scored more than four out of five, but by the end of last year dropped to 3.85, held by M&S Energy and EDF Energy.

Octopus Energy and Affect Energy were the second highest ranking suppliers, both with a score of 3.75 out of five. 

A spokesman for the Utilita said the rating system “did not fully represent what customers need from an energy supplier today” and that reviews website Trustpilot ranked the firm as second best for customer satisfaction. The firm said: “It does not take into account the financial support we provided on almost 200,000 occasions during the reporting period, nor the millions of households that our award-winning energy high five campaign has helped to cut their energy usage.

Dale Vince, founder of Ecotricity, said the company had seen a “significant increase” in contact with customers during the energy crisis, leading to longer phone calls. He said: “We’re working hard to improve performance, and thankfully we’ve already taken great steps forward since these numbers were recorded last year.”

Boost did not respond to a request for comment.