One in five households is wrongly billed by energy suppliers

Around one fifth of households have been billed incorrectly (Getty Images)

It’s time to check your energy bill – you could be one of the 20 per cent of households who’s been hit with the wrong charges in the past two years.

The cock-up could you leave you owing hundreds of pounds. The number of households that have suddenly ended up owing money to their energy supplier after a discrepancy between an estimated bill and a "real" bill, has soared to more than 10 million, reckons uSwitch in a report published today.

While the average amount owed is now £146, 14 per cent of people have unexpectedly ended up owing between £200 and £400, while seven per cent have suddenly discovered they owe more than £400, despite diligently paying their bill.

Ann Robinson, director of consumer policy at uSwitch, said: “The fact that consumers cannot rely on the accuracy of their bills is unacceptable as blunders can leave them out of pocket. There is a toxic link between estimated bills, inaccuracy and debt, which has to be broken.”

The figures are published just days after Ofgem revealed that the Big Six energy firms owe customers more than £400m that they’ve kept after customers have switched supplier or moved house.

The damning report from the comparison site also shames energy firms by revealing that companies are now taking almost twice as long to resolve their customers’ billing issues, with it taking an average of two months to sort things out.

“Estimated bills should come with a health warning and with a very simple message and advice about them,” said Ms Robinson. “If a bill is estimated then the customer should be encouraged to get in touch with a correct reading so that an updated and accurate bill can be sent.”

Energy UK, which represents the big gas and electricity companies said: “We know we still have work to do. But customers can help by making sure suppliers have regular meter readings.”