Police are asking shoppers to pay close attention to currency after a counterfeit bill turned up at Tim Hortons last week.

The five-dollar note was slightly smaller than an authentic bill, it was missing the metallic strip along the side, the colour was slightly different, and the serial code began with an obscenity.

Sgt. Laurie Jalbert of the Cranbrook/Kimberley RCMP said eight counterfeit bills have been reported in the area since September 2010. Those abnormalities are typical of a counterfeit, she added.

"The size gives it away - often they will be just a little bit shorter or just a slightly different size," said Sgt. Jalbert.

"One of the big things I note is there is a definite feel to currency. It is thicker than a lot of the counterfeit stuff I have seen," she said.

"We are looking for the holograms and the dots that are embedded inside the ink," said Jalbert. "There are all sorts of things you can look for, but those are the key ones."

The RCMP detachment has kits to help identify counterfeit bills, and banks have special equipment that can instantly tell the difference.

"The banks are the best place to take it and they can tell you in a heart beat if what you have is a counterfeit bill," said Jalbert.

If you can identify where the bill came from, the RCMP wants to know, especially if you were given it by an individual.

"If they know they got it from a store, chances are that store is not going to have any idea. Walmart is not going to know where that five-dollar bill came from," said Jalbert.

The RCMP sends counterfeit bills to its special counterfeiting section which, over time, can close the net on the fraudsters.

"When these guys print counterfeit bills, they don't put a different serial number on each one - they put a serial number on and it's the same one for every single one of them," said Jalbert. "So we can identify certain areas where five-dollar bills are being circulated. That may provide the basis for further investigation to break into a counterfeiting ring."

Jalbert mentioned a similar fraud that is becoming more common: counterfeit cheques.

"People think that money orders are infallible and really they're not," she said. "One of the frauds that is going on right now is where people are being told they can assist with sales out of their home and they are issued a cheque up front. That cheque is not real."