Police in Montrose have warned local businesses of a spike in cases of fake cash being used in the area.
The counterfeit notes have been used in a number of shops to purchase goods.
Officers in Angus said enquiries were at an early stage, but the notes involved predominantly seemed to be fake Bank Of England £20 notes and Ulster Bank £20 notes.
A Police Scotland spokesperson said: “We are currently dealing with a number of incidents in Montrose over the past couple of days where fake notes have been passed to buy goods in local shops.
Over a dozen cases
“We have been notified of over a dozen incidents so far, and there may be more that we have not yet been informed of.
“Higher-denomination English and Northern Irish notes are often used by fraudsters, as they are not commonly seen or used here and local businesses are often unfamiliar with them.
“If you are a local business and believe you may have been passed fake notes and haven’t notified us already, please call 101 and let us know.”
What do with fake bank notes
Police Scotland advised people to access the Bank of England website, which has training materials to help people spot fake cash.
The Bank of England said it cannot reimburse people for counterfeit notes.
It says: “Counterfeit banknotes are rare and also worthless.
“We cannot reimburse you for counterfeit banknotes. If you suspect that you have a counterfeit banknote, please take it to your nearest police station. The police should fill out an NCO-1 form and provide you with a receipt and incident number.
“The suspect notes will be sent to the National Crime Agency and if counterfeit to the Bank of England for further examination.
“If you have information about someone making, selling or using counterfeit banknotes, please contact the police or phone Crimestoppers anonymously on 0800 555 111.”