Worried that your household bills are more than expected? Then check your gas and electricity bills as a new report reveals that 9 million households (one in three) regularly get sent an incorrect energy bill.

uSwitch report that customer bills only match energy usage 26% of the time. The average consumer is in debt to their energy supplier by just over £135. More than 1 in 10 consumers owe their energy supplier between £201 – £500. But it could be your supplier that are in debt to you, as 40% of customers were owed money from their last bill.

These findings are being blamed on outdated meter technology, and uSwitch believes that these discrepancies will continue until smart meters are widely introduced throughout the UK. The advice to households is to keep an eye on their meter readings more regularly. “Relying on estimates is never a good idea as you could end up in debt or struggling with an unexpected bill” says Ann Robinson, Director of Consumer Policy at uSwitch.

Energy bills were not the only ones which were deemed the most inaccurate, others include tax bills from HM Revenue & Customs, council tax bills, water bills and communications providers bills for broadband/landline/digital TV.