Officers said the post offices were targeted with a 'ringing the change' scam at locations in Culbokie, Strathpeffer and Drumnadrochit.
Police are urging small businesses and cashiers to be vigilant after three post offices in the Highlands were defrauded out of hundreds of pounds.
Officers said the post offices were targeted with a “ringing the change” scam at locations in Culbokie, Strathpeffer and Drumnadrochit between Monday and Thursday.
In each incident, a man approached the cashier and asked for larger denomination notes for his smaller notes.
When he gets the cash, he cancels the transaction but only hands back some of the money.
The cashier only realises when the man has left the store.
There was a fourth post office targeted in Cromarty but the man did not get away with any cash, officers said.
The man involved in the Culbokie incident is described as white, 40 to 45-years-of-age, 5 ft 8 in height, stocky build and facial hair.
He was wearing a beige coat, denim jeans, and a cap. It is believed he had what is described as an Eastern European accent.
In Cromarty, the man is described as white, late 30s-early 40s, 5 ft 2 in height, medium build, with short brown receding hair.
He was wearing a black padded jacket and dark trousers.
Inspector Daniel Jack, North Highland Area Command, said: “We are urging businesses to be extra cautious if you are asked to change large sums of money by a member of the public.
“We’d advise calling a colleague or supervisor over to double-check amounts.
“At this point we cannot confirm if the incidents are linked but, on each occasion, it is a lone man who is involved.
“If you have any information about these incidents, are someone who had this happen to or had an attempt at at their store but who has not yet advised police, then please call.
“Information can be passed to officers at Dingwall Police Station via 101 quoting reference number 1926 of Wednesday, March 5, 2025 or call Crimestoppers anonymously on 0800 555 111.”