Customers of more than a dozen third-party electric suppliers will receive refund checks due to systematic rate notice errors dating back to 2016. The refund announcement was made June 21 by Attorney General William Tong's office. The errors were suspected as far back as 2015 when the attorney general's office and Office of Consumer Counsel urged the Public Utilities Regulatory Authority (PURA) to put in place measures to ensure the accuracy of electric suppliers' reported rates. "Then in 2018, former State Sen. Len Suzio filed a complaint with PURA after noticing his electric bills listed the wrong 'next cycle rate' for his electric supplier. In his case, his bills stated his next cycle rate at 7 cents per kWh, when in fact he was charged12.99 cents per kWh," a press release from Tong's office said, adding that such a billing error could have resulted in an overcharge of $45 per month, adding up to substantial amounts from 2016 through early 2019. Had the correct next cycle rate been listed, consumers could have used the information to change to a lower cost supplier or switch to the standard service offer of their respective electric utility -Eversource Energy or United Illuminating. Refund checks will be mailed through this summer. Third-party suppliers who must provide refunds include: Aequitas Energy, Inc.; Agera Energy, LLC; Ambit Northeast, LLC; Choice Energy, LLC; Constellation New Energy, Inc.; Direct Energy Services, LLC; Discount Power, Inc.; Energy Plus Holdings, LLC; Engie Retail, LLC d\/b\/a Think Energy; Hiko Energy, LLC; Liberty Power Holdings; Major Energy Electric Services, LLC;; North American Power and Gas, LLC; Reliant Energy Northeast; Perigee Energy, LLC; Spark Energy, LLC; Town Square Energy, LLC; and Verde Energy, LLC.