Which tool is commonly used by bank tellers to detect counterfeit money?

The use of UV light and counterfeit detection pens is essential for bank tellers when it comes to identifying counterfeit money. UV lights can illuminate specific features on legitimate banknotes that are not visible under standard lighting conditions, such as watermarks and security threads. These features often glow in a certain way under ultraviolet light, making it easier for tellers to distinguish genuine notes from counterfeit ones.

Counterfeit detection pens are another practical tool. They contain an iodine solution that reacts with the starch in the paper. Genuine bills are made from a specific type of cotton-linen blend that does not contain starch, so when the pen is applied to real currency, it will not change color. However, if the pen leaves a dark mark, it indicates that the paper is likely counterfeit since counterfeiters typically use regular paper, which does contain starch.

Together, these tools significantly enhance the tellers' ability to ensure that the bills they handle are authentic, safeguarding both the bank's interests and the customer's trust in their services. The reliance on these specific tools underscores their pivotal role in maintaining currency integrity within financial transactions.