Guelph and Rockwood residents will be getting a one-time credit on their hydro bills.
Alectra Utilities Corporation is issuing this credit as an acknowledgement for overcharging their customers in all rate classes for a number of years.
The Ontario Energy Board issued a news release saying it has approved the assurance of voluntary compliance from Alectra.
It says Alectra will issue its customers in the Guelph Rate Zone a credit in an amount equivalent to four years of overcharges, totaling approximately $1.24 million.
The OEB says Alectra determined a small proportion of customers in the four other rate zones were affected by the same billing error and have corrected the issue.
Alectra issued its own statement saying each customer will be reimbursed $20.66 and has apologized for the error.
Customers will see the credit on their bills within 90 days.