Consumers stand to reclaim £1.3bn from utility suppliers for overpaying on energy bills, new figures suggest.
More than 11m households could recover average credit of around £117 for energy they paid for but did not use over the winter, according to research from price comparison service uSwitch.
Seven per cent are set to get over £200 back from their utility.
"Today’s research shows the importance of providing regular meter readings. Otherwise energy bills can quickly become inaccurate, tipping people into credit or debt on their accounts," said Claire Osborne, uSwitch energy expert.
"Under Ofgem rules, providers must repay any credit on request."
Britain's energy bills have doubled in the past decade to around £1,200 a year, according to Reuters.
The government promised "muscular" action on unnecessary price hikes, but a new Conservative plan to offer a cap on prices has come under fire from energy bosses and consumer groups for being ineffective.