How to Check for Fake Bills and What to Do Next

The presence of counterfeit currency affects individuals and the broader economy. Understanding how to identify fake bills is important for safeguarding personal finances and maintaining trust in the monetary system. Knowledge of specific security features helps individuals protect themselves from accepting fraudulent money. This awareness contributes to the effort against counterfeiting, which undermines the value and stability of legitimate currency.

Methods for Identifying Counterfeit Bills

Authenticating United States currency involves examining several security features, starting with the feel of the paper itself. Genuine U.S. dollar bills are produced from a blend of 75% cotton and 25% linen, giving them a unique, slightly rough texture. This tactile quality is difficult for counterfeiters to replicate, as fake bills often feel smoother, thinner, or waxy due to being printed on regular paper. Authentic currency also features raised printing, particularly noticeable on the portrait and around the seals, which can be felt by running a fingernail lightly over the surface.

Holding a bill up to light reveals embedded security features. A watermark, a faint image matching the portrait on the bill (or numerals on the $5 note), should be visible to the right of the portrait on denominations $5 and higher. A security thread is embedded vertically within the paper, not printed on it, on denominations $5 and higher. This thread is positioned differently for each denomination and will glow a specific color under ultraviolet (UV) light, such as blue for a $5 bill or pink for a $100 bill.

Tilting the bill can reveal dynamic visual features. Color-shifting ink is present on the numeral in the lower right corner of denominations $10 and higher, changing color from copper to green when the bill is tilted. On the redesigned $100 note, the “Bell in the Inkwell” also exhibits this color-shifting property. Newer denominations incorporate a 3-D security ribbon woven into the paper, featuring images of bells and the numeral “100” that appear to move when the bill is tilted.

Microprinting is another security feature found in various locations on denominations $5 and higher. This tiny, intricate text may appear around the portrait or within the security thread. It should be sharp and legible under magnification, not blurry or smudged. Genuine U.S. currency paper also contains tiny red and blue fibers randomly embedded throughout the material, which are part of the paper itself rather than printed on its surface.

Counterfeit detection pens are often used as a quick check, but they have limitations. These pens contain an iodine-based solution that reacts with starch, which is present in most regular wood-based papers but not in genuine U.S. currency paper. A dark brown or black mark indicates the presence of starch, suggesting a counterfeit bill, while a pale yellow or clear mark indicates genuine currency.

However, these pens cannot detect sophisticated counterfeits printed on starch-free paper. They also cannot detect bills made by bleaching lower-denomination genuine bills and reprinting them with higher values, as the original paper remains authentic. Relying solely on a counterfeit detection pen is not a comprehensive method for authentication. Comparing a suspicious bill to a known genuine bill of the same denomination and series can help highlight differences in security features.

What to Do if You Suspect a Counterfeit Bill

If you receive a bill that you suspect is counterfeit, handle it carefully to preserve potential evidence. Do not return the suspicious bill to the person who passed it to you. Limit handling the bill as much as possible, perhaps by placing it in an envelope or plastic bag. This minimizes the disturbance of fingerprints or other evidence that law enforcement may be able to collect.

Attempt to recall and note any identifying details about the person who presented the bill. This includes their physical description, actions, and any vehicle information, including license plate numbers. Make a mental note of the time, date, and location where the transaction occurred. This information can be crucial for authorities investigating the source of the counterfeit currency.

Immediately contact your local police department or the nearest United States Secret Service field office to report the suspected counterfeit. Surrender the bill only to a police officer or a Secret Service agent. Be prepared to provide all the details you observed about the individual and the circumstances surrounding the receipt of the bill. If the bill is confirmed to be counterfeit, you will not be reimbursed for its face value by the authorities or financial institutions, as counterfeit money has no legal value.