EDF and Utilita have been named the worst energy suppliers for customer service in a quarterly ranking by Citizens Advice.
The consumer charity said customer service ratings across the industry were among the lowest ever, reporting that record numbers of households asked it for help with energy issues between January and March.
Research by the charity has found more than five million people in the UK are living in households in debt to their supplier.
Average customer ratings for firms had fallen by 10.5% compared to the same period in 2021, and had flatlined since the end of 2023.
The charity said customer service standards had still not returned to levels seen before the energy crisis, which caused many more people to need support from their suppliers with issues like debt and the force-fitting of prepayment meters.
Citizens Advice is calling for the introduction of a “Consumer Duty” – a new set of rules that would give Ofgem stronger powers to hold companies to account and help bring an end to “years of poor customer service”.
The latest ranking puts Ecotricity at the top of the table, followed by Outfox the Market, Ovo Energy and Utility Warehouse.
Also in the top 10, E (Gas and Electricity) ranked at number five, with E.ON, ScottishPower, Good Energy, Rebel Energy and Octopus Energy following behind.
In the lower third, Co-Operative Energy ranked at number 11 with a score of 2.52, followed by Boost Power and So Energy. British Gas ranked number 14 with a two-star score of 2.39.
EDF, one of the highest-scoring suppliers this time last year, has fallen to the very bottom after its average call waiting times jumped from just under a minute to more than five minutes in less than a year.
Utilita has improved since last quarter but remains one of the lowest-rated suppliers.
Citizens Advice said there had been an improvement in average call waiting times following new guidance from Ofgem in December.
However, companies were performing badly on their ability to resolve customer complaints, which had brought overall ratings down.
Citizens Advice chief executive Dame Clare Moriarty said: “When millions are struggling to afford the essentials, it’s completely unacceptable that energy companies are failing to give their customers proper support.
“Citizens Advice has long called for Ofgem to be given stronger powers to hold suppliers to account on customer service. That must include tackling the complaints backlog before next winter.
“News that bills are dropping slightly from July will be cold comfort for the record numbers seeking help from our advisers. The next government must introduce better targeted energy bill support for those struggling to keep the lights on or cook a hot meal.”
An EDF spokeswoman said: “We recognise our call answer times haven’t been up to the high standards we set ourselves and we’re committed to doing better, getting back to the market-leading service our customers expect.
“We’ve recruited and trained more people at our Sunderland, Brighton and Exeter offices and are nearing the end of a complex transfer of our residential customers to a new IT system, resulting in more customers getting in touch as we navigate this process.”
Utilita said: “We must not underestimate how savvy consumers are today. They will realise the Star Rating contradicts other market-wide supplier assessments – including those of Ofgem, Trustpilot and Which? – where Utilita performs consistently well.
“As such, we look forward to ongoing dialogue to close the gap between the perception the Citizens Advice Star Rating gives, and the reality other rankings provide.”