Police are warning people to be on the lookout for counterfeit money (file photo).

Palmerston North is awash in counterfeit money.

Since Monday, people have tried to use at least eight fake $50 notes at supermarkets, pubs and service stations.

"We are asking the community to ensure they pay extra attention to any larger denomination notes they come into contact with," Constable Mark Reid said.

"People who work in jobs where they handle cash are also asked to take extra care."

He said if people suspected they were being given counterfeit money they should politely refuse to accept it.

"Please report to the police that someone potentially attempted to pass a counterfeit note.

"If you are in possession of a suspect banknote, store the banknote safely and handle it as little as possible."

He said stores should note all relevant details such as the date, time and place of receipt, car registration number of who handed it over and, if they had, CCTV.

"Please hand any suspect banknote to police as soon as possible and provide any details around how you came into possession of it."

Anyone with information can contact their local police or anonymously call Crimestoppers on 0800 555 111.