I have seen counterfeit detection pens used to mark suspect notes. How well do they work?
Counterfeit detection pens are not always accurate and may give you false results. Rather than using these pens, consumers and cash handlers should check the note’s security features to guarantee its authenticity. Three new features were incorporated into notes in the 1990s and have been enhanced for the Series 2004 notes: security thread, color-shifting ink, and the watermark. Features vary depending on denomination. To learn more about the security features please visit the Bureau of Engraving and Printing’s web site.
