CHEYENNE, Wyo. (AP) — A review by Cheyenne Light, Fuel and Power of its 41,000 accounts found billing mistakes in 4,455 of them.

Most mistakes involved overcharging rural residents in Laramie County when the utility incorrectly charged them with a 2 percent franchise fee.

Cheyenne Light pays franchise fees to the city of Cheyenne for use and access of city alleys and streets to run utility lines.

Mark Stege, of Cheyenne Light, says any overbilling charges will be paid back with interest.

The Wyoming Tribune Eagle reports that representatives from Cheyenne Light told the state's Public Service Commission on Monday about the mistakes and how it will fix them.

Stege says Cheyenne Light doesn't have dollar amounts for the mistakes yet and doesn't know why the billing errors occurred.