How Can You Tell If a $100 Bill Is Real?
Every day, thousands of $100 bills exchange hands around the world. Whether you’re running a cash-based business, working in finance, or just receive cash occasionally, knowing how to identify counterfeit money is an essential skill. Of all U.S. currency denominations, the $100 bill is the most commonly counterfeited outside the United States. As counterfeiters grow more advanced, it’s more important than ever to know what to look for. The good news? The U.S. Department of the Treasury includes multiple security features to help you confidently verify the authenticity of your money.
In this blog post, we’ll show you how to tell if a $100 bill is real by examining the bill’s security features, physical properties, and some simple yet effective techniques for detection. Let’s dive in.
Why the $100 Bill Is a Frequent Target for Counterfeiters
The $100 note is among the highest-value denominations in circulation. It’s commonly used in international transactions and is often held as a store of value rather than a means of everyday transaction. Because of its high value and widespread use, counterfeiters target $100 bills in hopes of scoring big returns. That’s why it’s crucial to become familiar with the authentic features designed to protect you from fraud.
Key Security Features to Look For
The current design of the $100 bill, sometimes referred to as the “new series” or “blue stripe” version, was released in 2013. It includes multiple complex elements that are difficult to reproduce, even with sophisticated technology.
1. 3D Security Ribbon
One of the most distinctive features of the new $100 bill is the blue 3D security ribbon that runs vertically on the front of the note. This ribbon is woven—not printed—into the paper. When you tilt the bill back and forth, you’ll see the images of bells change to 100s and move in an opposite direction of your movement. The 3D motion effect is very difficult to counterfeit and one of the easiest features to check visually and tactilely.
2. Bell in the Inkwell
Next, look for the color-shifting bell inside the copper-colored inkwell to the right of the portrait. Tilt the bill, and you’ll notice that the bell changes from copper to green. This gives the illusion that the bell is appearing and disappearing. It’s subtle but highly effective—and not something that counterfeiters can easily duplicate with basic printing.
3. Security Thread
Hold the bill up to light, and you should find a security thread running vertically to the left of Benjamin Franklin’s portrait. This embedded thread glows pink under ultraviolet (UV) light and is clearly visible when held up against a light source. You should also see the letters “USA” and the number “100” repeated along the thread.
4. Watermark
Another telltale sign of authenticity is the faint image of Benjamin Franklin visible on the right side of the note when it’s held up to the light. This watermark should be apparent from both sides of the bill and perfectly aligned with the printed portrait.
5. Color-Shifting Ink
In addition to the bell-in-inkwell feature, the lower right corner of the front of the note displays the number “100” printed in color-shifting ink. Tilt the bill, and you’ll see the color shift from copper to green, providing another easy way to check validity.
6. Raised Printing
Authentic U.S. currency is printed using an intaglio printing process, which gives the surface of the bill a unique texture. Run your fingernail across Franklin’s shoulder or the large “100” numbers, and you should feel the ink slightly raised from the paper. Counterfeit bills tend to feel flat or waxy since most are printed using digital or laser printers.
7. Microprinting
Closely examine the $100 bill with a magnifying glass, and you’ll find small, detailed text in several locations. Examples include:
- “The United States of America” around the quill of the inkwell
- “USA 100” inside the golden quill on the front of the note
- “USA” repeated in the background between Franklin’s shoulder and the security thread
Microprinting is extremely difficult to replicate with standard printers, which often blur or distort the tiny font.
Physical Properties of the Paper
Beyond the visual features, authentic U.S. currency is printed on a proprietary blend of cotton and linen paper. It does not contain normal wood-based paper fibers, which makes it feel distinctly different from common paper. The paper also includes red and blue security fibers embedded throughout, visible under magnification.
If the bill feels softer, thinner, or unusually stiff, it might be a fake. Trust your instincts—your fingers can be just as reliable as your eyes when identifying suspicious notes.
Simple Techniques to Verify Authenticity
In addition to knowing the security features, there are some easy methods you can apply to test a $100 bill’s legitimacy:
1. The Light Test
Hold the bill up to a light source. You should be able to see:
- The embedded security thread with glowing properties
- The faint watermark of Franklin’s portrait
- Consistent spacing and alignment between the elements
2. Feel the Paper
No regular paper mimics the texture of real currency. Rub the note between your fingers and feel for the raised ink and unique stiffness of the cotton/linen blend.
3. UV Light Test
If you have access to an ultraviolet light, place the note under it. Genuine $100 bills will reveal a pink or red glow from the embedded security thread. Older $100 bills, pre-2013 series, glow a specific color (more commonly red or orange), but not in the same position or with the same intensity. Counterfeits often fail this test entirely.
4. Use a Counterfeit Detection Pen
Many retailers use counterfeit detection pens, which contain iodine and react to starches in regular paper. If the mark turns dark, the note is likely a fake. If it remains light yellow, the bill may be real. However, be cautious—advanced counterfeiters may treat their bills or use starch-free paper, so this test should not be used in isolation.
What to Do If You Suspect a Counterfeit
If you come across a suspicious $100 bill, here’s what you should do:
- Do not return the note to the person who gave it to you.
- Note the person’s description and any details of the transaction.
- Contact your local authorities or the U.S. Secret Service field office.
- Handle the note as little as possible and place it in a protective envelope.
Intentionally passing counterfeit money, even if you received it unknowingly, is illegal. Always report suspicious activity promptly.
Bottom Line: Trust Your Senses and Stay Informed
With all the impressive design features in place, authenticating a $100 bill has become easier—provided you know what to look for. Use light, motion, feel, and magnification to quickly assess a note’s legitimacy. If you remain vigilant and informed, you minimize your risk of falling victim to counterfeit currency.
At the end of the day, it’s about combining knowledge with simple observation skills. By keeping an eye (and a hand) on these details, you’ll become more confident in distinguishing real currency from fake, protecting your finances and reputation with every transaction.
