How to Detect Counterfeit Dollar Bills

by Petr Novák, ? This article’s information was last verified on this date. If you notice any errors, let us know in the comments. Thank you! :-) Updated 05/31/2023 Fun Facts, How It Works in America

If you pay with cash, you might notice that the cashier in the USA marks the bill with a pen. This often happens with larger denominations, as the cashier is verifying the bill’s authenticity. It’s estimated that approximately 0.01% of banknotes in circulation are counterfeit, equating to one in every 10,000 banknotes.

Pen for Detecting Counterfeit Banknotes

A unique iodine-based pen is used to identify counterfeit banknotes. This detection pen can authenticate dollars, euros, Swiss francs, and other currencies.
The paper used for these banknotes is made from cotton fiber and does not contain starch, which is typically present in regular office paper used for producing most counterfeit bills.

Detection pens contain iodine solution, which specifically reacts with starch. If the marking on the banknote turns yellow, it’s most likely authentic. If it stays black or blue, the banknote is counterfeit.

You can purchase a counterfeit detection pen on eBay by searching for “Counterfeit Banknote Pen”.