EDF Energy, one of the UK’s largest energy suppliers, is the worst performing amongst the Big Six and has retained its ‘zero-star rating’, according to research from Consumer Focus. The most recent quarterly energy complaints data shows a small overall decrease in complaints levels across the industry. Customers speaking out fell overall by an average of 4% between October and December 2011.

Audrey Gallacher, Director of Energy at Consumer Focus said: “EDF Energy has made some headway on addressing its problems but it is disappointing that the company remains firmly on the bottom of the league table again. Customers will rightly expect EDF Energy to take this further in hand, so it is welcome they have assured us that further progress has been made since December. The company has had ongoing problems for over half a year.”

EDF said they were “disappointed” with the findings but were looking at the positives with complaints falling 14% since the last quarter. In a statement the firm said: “It’s important to note, the table released by Consumer Focus today relates back to data for the last quarter of 2011. Since that period, we have successfully completed the migration of all our customers to our new upgraded customer service system. Service levels have been stabilised and we are confident customers will see a significant improvement in service levels this year.”

Complaints about four of the Big Six suppliers fell during the time frame, but all firms but one maintained their rating. Only npower moved up the ranks, regaining its three-star status after dropping to two stars in the previous quarter.

The results for October to December 2011 were:

SSE- 5*

British Gas- 4*

ScottishPower- 3*

E.ON- 3*

Npower- 3*

EDF- 0