You may have a cottage you don't get to in the winter or live outside of Toronto and received electricity bills for thousands of dollars.
Ontario's ombudsman says it's a common problem and he's going to look into it.
Andre Marin's investigation will centre on billing and customer service at Hydro One, two things the Ombudsman's office has been receiving over a thousand complaints on over the past few years.
Most people say their bills are wrong.
Marin says he's received complaints about people getting huge catch-up bills, a tally Hydro One threw together after customers had either estimated or no bills for a long period of time.
"In the past few years, we have seen more and more complaints from Hydro One users about bills that seem to have no bearing in reality - and about the lack of answers they get when they ask why," according to Marin.
There have also been people complaining of waiting forever but not getting proper information from customer service.
Marin is expected to wrap-up his investigation in nine months.