Conway Corporation, the city-owned utility service, sent letters to all customers Wednesday advising that an error in electricity billing resulted in residential and small commercial accounts being underbilled since June.

The letter explained that Conway Corp. had inadvertently charged the lower winter rate since June and that customers would be asked to repay the difference at a rate calculated to make up the difference over the next three months. The extra payment will be added onto customer bills by Conway Corp.

Conway Corp. CEO Richard Arnold said Wednesday that the error was caused when an employee "just forgot to change the rate."

For the average customer, Arnold said, the difference will come to about $50. If customers wish to make the payment all at once, he said, it can be arranged, also saying that "we do recognize that the economy’s tough, so if there are extenuating circumstances that mean a customer needs more time to make the payments, we’ll look at that." 

Arnold added that the latest consumer price survey conducted by Entergy Arkansas shows Conway Corp. electric service to be the fourth-cheapest in the state, behind Jonesboro, Mississippi County and West Memphis utility services.