Duke Energy customers will receive $1.7 million in refunds.
The utility giant is crediting 165,000 customers the funds because of over billing. Company officials admitted to the overcharging of customers in August.
Duke officials called the extra charges "unintended consequence" of changes to its meter reading system.
The charges stemmed from a one-time billing cycle adjustment that added 12 days of service to customer's monthly bills - adding as much as an extra $100 to bills.
The company has about 267,000 customers in Pinellas County.
Duke is changing its meter-reading routes to make them more efficient.
The project started in May 2013 and is expected to continue through December.