(ABC 6 News) – Zumbrota Police warn businesses to keep an eye out for counterfeit bills.

The department posted pictures of fake $100 bills used in the city.

The department says the fake hundreds were made using washed up 10 and $20 bills, meaning the counterfeit detection methods wouldn’t work on the false bills.

The department recommends looking for watermarks on the bills. The watermark of $100 bill should be an image of Benjamin Franklin.

Real $100 bills have a blue tint whereas $10 bills have an orange tint