(Charleston, IL) -- Charleston businesses and consumers are being urged to pay close attention to their paper money as counterfeit bills have been circulating in the area. Police say the fakes are mainly tens and twenties and they’ve been passed at several businesses. If you are on the receiving end of one of these phony bills, keep it and call police. Ten-dollar bills will have a security thread that reads “USA TEN,” which glows orange under a black light. Twenty-dollar bills have “USA TWENTY” written on the security thread, which glows green under a black light. Check for paper quality, colored threads, watermarks and color-shifting ink.