Local authorities are urging businesses in the region to use caution when accepting cash after a counterfeit bill was found to be in circulation in Manning. The Manning Chamber of Commerce says the phony $20 bill was located earlier this week following similar reports of counterfeit $10 bills being passed in Carroll. Detecting forged currency can be difficult, but there are ways for businesses to protect themselves. Authentic currency will feel slightly rough to the touch, and newer bills of denominations $10 and higher have color-shifting ink in the bottom right corner. All bills, except for $1 notes, have watermarks that appear when light is shined through them. Counterfeit detector pens can also be used to check the legitimacy of questionable bills.