At least 15 different regional energy providers have admitted to overcharging their Ontario customers for more than four years because they improperly calculated how many days there are in a year, according to published materials from the Ontario Energy Board.

From mid-August 2022 to mid-February 2023, the OEB published 15 Assurance of Voluntary Compliance (AVC) reports describing the problem, with the providers agreeing to credit $10.3 million to customers and pay an additional $118,750 in administrative monetary penalties.

The problems were discovered in 2021, when an energy distributor identified that it was incorrectly calculating the daily equivalent of the fixed monthly charges to its customers. The OEB sets a fixed monthly charge, which is a component of the amount each provider can bill customers. This particular distributor’s billing system converted the monthly amount into a daily amount by simply dividing by 30, instead of properly multiplying by 12 and then dividing by 365. This daily charge was then applied over the 365 (or 366) days in the calendar year, instead of the 360 days that the calculation was based upon. This resulted in an overcharge by five days each year on the fixed monthly charge allowed.

The OEB notified all licensed electricity distributors of the issue, and advised them to review their billing systems. A few did so in early 2022, but between mid-August 2022 and mid-February 2023, 15 providers admitted to the miscalculation. Some published reports indicated the overcharging for some providers may have dated back many more years but under the AVC, no providers have given credits to users for durations longer than four years.

All vendors are required to provide an explanation to customers in a form approved by the OEB, with the refund provided within 90 days of the AVC.