An annual survey from consumer group Which? showed that the overall customer rating for energy companies has dropped to 41 per cent from 49 per cent last year.
Npower scored the lowest for the third year running, at just 31 per cent.
“We know we’ve let many of our customers down following recent issues with our new billing system but it’s still disappointing to see these results,” said Roger Hattam, Npower’s director of its domestic retail business. “Right now, our priority is to put right these issues.”
British Gas received the second lowest score at 39 per cent. SSE and Scottish Power both came in at 41 per cent, EDF Energy scored 44 per cent and E.On 45 per cent. Smaller suppliers fared better, with the top spot held jointly by Good Energy and Ecotricity at 82 per cent.
“Companies put a very high value on the relationships they have with their customers and they are working hard to improve the service they provide,” said Energy UK.
Regulator Ofgem said that the figures reaffirmed the need for the market reforms it had started to implement.
Labour’s shadow energy secretary Caroline Flint said the survey results were “a damning indictment of a broken energy market”.