The quickest way to check is to feel the paper. Real US bills have a slight texture from the printing process.
US bills $10 and higher have color-shifting ink. The lower-right denomination should change from copper to green. When tilted, its pattern moves left and right, up and down.
Hold the bill up to the light. For any current $5 bill and higher, look for:
1. The watermark of the same face as the portrait side of the bill.
2. The security thread, in a different place on each denomination. It will also glow under UV light and the thread of each denomination glows a different color.
New $100 bills also have a 3D security ribbon.
To keep counterfeiters on their toes, the US Treasury continues to develop new security features.
Who knows what tricks they’ll come up with next?
