No matter how many security enhancements are made to Canadian banknotes, counterfeiters always seem to find a way to keep their bills circulating.

One Toronto-area resident learned that lesson the hard way 鈥� and now he鈥檚 warning others about his experience so they won鈥檛 suffer the losses he did.

Michael Boddy of Richmond Hill, Ont., says he unknowingly accepted 63 fake $20 bills from somebody who had agreed to buy a high-end iPhone he was selling.

It was dark out, he told CTV Toronto, but the bills looked and felt the way he would expect real $20s to feel 鈥� so he left without realizing anything was amiss.

It was only once Boddy returned to his home and examined the notes more closely that he started to suspect he鈥檇 been duped.

鈥淸I] started looking at it a little bit more and thinking 鈥楾his just doesn鈥檛 seem right,鈥欌�� he said.

The bills鈥� material didn鈥檛 have quite the same feel as the polymer of official currency. Some of the raised ink was missing. And many of the notes contained duplicate serial numbers.

鈥淏e careful selling your stuff, because there are crooks trying to get your stuff for free,鈥� Boddy said.

According to RCMP statistics, the number of counterfeit bills being passed in Canada has been rising since 2015, when the number of fake bills detected was at a long-term low.

Fake $20 bills circulating in British Columbia鈥檚 Fraser Valley last spring. Around the same time, police in London, Ont., received of fake $100 bills making their way around that city.

The Bank of Canada includes new security measures on each new series of banknotes it creates.

The central bank provides on how to detect counterfeit bills.

In general, for most newer-series banknotes, it recommends checking for difficult-to-counterfeit features such as a hologram in the otherwise transparent window of the bill, raised ink in places including the phrase 鈥淏ank of Canada,鈥� and a transparent outline around the maple leaf on the face side of the bill.

The have raised ink on the portrait, large number 10 and the word 鈥淐anada,鈥� as well as a picture of an eagle feather which changes colour from gold to green based on the angle it is being viewed at.

There were approximately 8,000 counterfeit notes detected in each of the first three quarters of 2018, with $100 and $20 denominations being the most common.