The UK’s electricity and gas regulator has launched an investigation into Ovo Energy over information the company gave some customers.
Ofgem is questioning Ovo’s estimates about the amount of energy its customers used during winter 2016-17, as well as the accuracy of the annual figures.
The investigation will examine whether Ovo Energy breached licence conditions.
An Ofgem spokesman said: “Incorrect consumption figures can lead to customers receiving inaccurate bills, annual statements and other important information. This in turn can lead to customers being unable to properly manage their accounts and deciding to switch based on incorrect information.
“The opening of this investigation does not imply that we have made any findings about non-compliance by Ovo Energy.”