Police have warned shoppers and business owners that fake bank notes may be in use around the Bourne area.
Officers have received several reports that forged £20 notes are being circulated in and around the town.
The forged notes carry the serial number AE54919120.
Officers have called on people to be on the look out for the counterfeit cash and to report any they may come across.
Call police on 101 to report fake notes.