The gap between how well the best and worst performing energy suppliers are at dealing with customer complaints is the widest on record, according to Citizens Advice. The difference between the companies at the top and bottom of the table is at its widest since the table began five years ago.

Bottom of the table Extra Energy performed 80 times worse than the best performing supplier SSE, according to the charity’s energy complaints league table for the last quarter. Common problems that people reported to Citizens Advice about Extra Energy included late or inaccurate bills and difficulty getting through to its customer service team on the phone when they had an issue to resolve.

Suppliers’ scores are calculated based on the seriousness of the complaint against them and how long it took to resolve. Firms with lower complaints ratios are better at resolving complaints than those with high scores.

Citizens Advice’s latest table of the 21 largest energy firms in Great Britain, for April to June 2016, showed:

• Extra Energy remains at bottom of the table for second quarter in a row  - recording highest ever complaint ratio of 1791.2 per 100,000 customers, compared to 1,682.0 per 100,000 customers the previous quarter.

• SSE retained the top spot with improved performance – getting a complaints ratio of 22.5 per 100,000 customers, compared to 28.4 per 100,000 the previous quarter.

• Last quarter’s second best performer Flow Energy dropped to tenth place, with a fourfold increase in its complaints ratio compared to the previous three months.

• Npower’s complaints ratio drops by over a third – however its rank remains unchanged as a new supplier enters the table in a higher position.

• Newcomer GB Energy secured 9th place with a complaints ratio of 125.4 per 100,000 customers.

• Utilita more than halved its complaints ratio, while Ecotricity has doubled its complaints ratio compared to last quarter.

Gillian Guy, chief executive of Citizens Advice, said: “People shouldn’t face a gamble on getting good customer service. The latest league table shows some suppliers are getting much better at sorting out their customers’ problems, but it’s disappointing to see others getting worse at dealing with complaints.

“Patchy and unpredictable customer service affects people in many ways – from the financial stress of being hit with a late bill, to the time wasted trying to get hold of a supplier on the phone.

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