Two of the Big Six firms have been found to be the best in managing customers’ complaints.
EDF and SSE have a ratio of less than 50 complaints per 100,000 customers, according to Citizens Advice’s list which analysed 19 suppliers in the country.
They are followed by British Gas with an average of 65.3 complaints per 100,000 customers.
On the other hand, small suppliers Extra Energy and Co-operative Energy are the worst performing companies with a ratio of more than 1,000 complaints per 100,000 customers.
Citizens Advice added the average complaints ratio for all companies is down with 275 registered per 100,000 customers
Althoug npower and ScottishPower have delivered improved performances, they continue to be the worst ranking Big Six suppliers, it added.
Gillian Guy, Chief Executive of Citizens Advice said: “This latest league table tells two different stories – some suppliers have again proven they’re effective at dealing with customer complaints while others lag far behind. Consumers already pay over the odds for their energy bills and it’s unacceptable that some are still being let down by poor customer service.
“On the face of it, it is good the overall number of complaints are steadily decreasing. For those suppliers who still have a long way to go, there is an opportunity to learn from the feedback they are getting from their customers. Complaints not only give suppliers the chance to put problems right, they also provide valuable insight which can be used to improve services.”
According to the CMA report from last week, householders pay £1.7 billion more a year than they would in a competitive market.