Data from comparison site uSwitch found the average household in credit with their energy supplier could stand to reclaim £117, while 7% could reclaim more than £200.

Its research found 66% of customers took some action to cut their winter energy bills, including turning down the thermostat, turning down individual radiators or setting the heating to come on for less time every day.

uSwitch said customers should check their gas and electricity meters, submit their readings and find out if they’re in credit.

Many suppliers automatically refund credit balances once a year, but this may be subject to a minimum amount and refund policies vary between providers. Under Ofgem rules, customers are entitled to any credit on request, as long as up-to-date meter readings have been provided.

uSwitch found that rather than reclaim their money, almost four in ten (38%) plan to keep their energy account in credit in a bid to cope with price rises, as many are already worrying about soaring energy bills, even though many price hikes from the major suppliers are yet to take effect.

Once the hikes hit customers, a third said they would struggle to pay increased bills, while 22% said an increase of £100 or more would force them into debt.

As well as those in credit with their supplier, 14% of consumers – more than 3.7 million households – are in debt with their provider following the winter.

Claire Osborne, uSwitch.com energy expert, said: “Consumers should submit an up-to-date meter reading now to find out if they’re owed cash from their energy supplier. 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.

“Under Ofgem rules, providers must repay any credit on request, so now is the time to read your meter, update your account and reclaim what you’re owed. Consumers who are building up credit to soften the blow of price hikes should instead consider reclaiming this money and switching to a cheaper deal. With an average credit refund of £117 and savings of over £350 by switching supplier, it could be a very effective way to control spiralling energy bills.

“With a range of suppliers raising prices over the past few months, any consumers who find themselves in debt should get in touch with their supplier right away to prevent the situation from getting any worse.”