Windsor police are warning people and retailers of counterfeit bills circulating through the area.

A number of U.S. counterfeit $20 bills have been passed around over the past few weeks. 

Police are advising people to check for more security features on the bill to makes sure it's real. 

They say this particular $20 counterfeits can be easily detected when compared to a regular note. 

How to tell it's fake

  • Watermark: Hold the bill up to the light and look through it. There should be a small watermark to the portrait. 
  • Colour-Shifting-Ink: Look at the number "20" in the lower, right corner of the bill. A real $20 bill changes colour from copper to green when you tilt it up and down. 
  • Security Thread: Hold the bill up to the light and look through it. You should be able to see a security thread embedded in the note that runs vertically up on side. 

If people come across a counterfeit bank note they are being asked to call police at 519-255-6700 ext 4330.