Few objects in everyday commerce attract as much quiet scrutiny as a one-hundred-dollar bill. It is the largest denomination in routine circulation in the United States, which makes it the prime target for counterfeiters and, at the same time, the note most likely to be checked twice by a cautious cashier. Whether you run a small retail shop, work a register, handle tips in cash, or simply want to protect yourself during a private sale, understanding what separates a genuine note from a fake one is a practical skill worth having.
Counterfeiting is not a rare curiosity confined to history books. The United States Secret Service, which was originally created in 1865 specifically to combat currency fraud, still investigates thousands of counterfeiting cases each year, and the $100 note consistently ranks among the most imitated denominations worldwide. This article breaks down the security features built into modern hundred-dollar bills, explains the red flags that show up most often in the field, and walks through what the law says and what you should actually do if one lands in your hand.
How to Identify a Counterfeit $100 Bill
The current design, often called the "Blue Ribbon" or 2013 series note, was introduced to make life considerably harder for anyone attempting to reproduce it. The Bureau of Engraving and Printing layered multiple features into the paper, the ink, and the printing process itself, so that a single glance or a single test is rarely enough to confirm authenticity. That layering is deliberate: it forces anyone verifying a note to check several independent characteristics rather than trusting one simple trick.
It is important to understand that counterfeit quality varies enormously. Some fakes are crude inkjet prints that fail the first touch test, while others are sophisticated enough to fool experienced bank tellers and even automated counting machines. The goal of a good verification routine is not to memorize one magic feature but to build a habit of checking three or four features together in a few seconds.
Security Features Built Into the Current Series
The most talked-about element is the blue 3D security ribbon woven into the paper, not printed on top of it. When you tilt the note back and forth, the bells and the numeral "100" inside the ribbon appear to move side to side and up and down. The ribbon also contains microprinting that becomes visible under magnification. Because the ribbon is woven into the substrate during manufacturing, replicating it convincingly is extremely difficult for anyone lacking industrial papermaking equipment.
Alongside the ribbon, several older but still effective features remain. The portrait of Benjamin Franklin is rendered in intaglio printing, giving it a subtly raised texture you can feel by running a fingernail across the collar or shoulder. A faint watermark of Franklin appears in the blank space to the right of the portrait and should be visible from both the front and the back when the note is held to light. A thin embedded security thread runs vertically to the left of the portrait and glows pink under ultraviolet light. The large copper-colored numeral "100" in the lower right corner shifts to green as you tilt the bill.
Common Red Flags and Field Tests
The counterfeit-detection pen, widely used at registers and flea markets, deserves a caveat. These iodine-based pens react to the starch found in ordinary wood-pulp paper, turning dark when starch is present. Genuine currency paper is a cotton-and-linen blend with no starch, so it stays pale. The problem is that counterfeiters have adapted by printing on starch-free paper or by bleaching genuine low-denomination notes and reprinting them as hundreds. In those cases the pen gives a false pass, which is why a pen should never be your only line of defense.
Several visual checks catch what the pen misses. Hold the bill up to a light source: the watermark should be embedded in the paper and should match the portrait, not be printed faintly on the surface. Look at the security thread position and confirm the microprinting along Franklin's collar reads "THE UNITED STATES OF AMERICA" crisply rather than dissolving into a blur. Check that the serial number uses the same ink and printing style as the rest of the note, and that the borders are sharp and evenly spaced. A washed note reprinted as a hundred often has a slightly off-white or grayish tone and a watermark that does not match the portrait at all.
The Legal and Economic Reality of Counterfeit Currency
Counterfeiting in the United States is a federal offense, not a minor infraction. Under 18 U.S.C. § 471, manufacturing, passing, or possessing counterfeit currency with fraudulent intent carries penalties of up to twenty years in prison and substantial fines. Related statutes cover the alteration of genuine notes, the possession of plates or digital files used to produce fakes, and the smuggling of counterfeit currency across borders. State laws often add their own penalties on top of the federal charges.
The economic cost is absorbed in a way many people do not expect. When a fake note is detected at a bank, it is seized and forwarded to the Secret Service, and the person or business that accepted it generally receives nothing in return. There is no insurance, no refund, and no reimbursement for the value of goods or change already handed over. A single convincing counterfeit hundred can wipe out the profit margin on an entire day of small transactions.
What Happens If You Accidentally Accept a Fake
The instinct to hand a suspicious bill back to the person who gave it to you is understandable but unwise. If you attempt to pass it onward, even unknowingly, you create a messy chain of custody and could expose yourself to scrutiny. The recommended approach is to keep the note, minimize how much you handle it, and place it in an envelope or protective sleeve so any fingerprints or other evidence remain intact. Try to note a physical description of the person and any vehicle details if it is safe to do so.
From there, contact your local police department and your regional Secret Service field office. The Secret Service publishes a Counterfeit Note Report that banks and businesses can submit, and your bank will typically confiscate the note and forward it to federal authorities when you bring it in. Some businesses train employees to follow a specific internal script and to notify a manager immediately rather than alerting the customer, which helps prevent confrontation while preserving the evidence.
Supernotes, Bleached Notes, and Evolving Threats
Among the most sophisticated fakes ever encountered are the so-called "supernotes," high-quality counterfeit hundreds that circulated for years before being widely identified. Investigators have linked their production to state-sponsored operations, and their print quality was good enough to defeat many standard detection methods and some older automated inspection equipment. Concerns about these notes were a direct motivation behind the dramatic redesign of the hundred-dollar bill.
A separate and more common threat is the bleached note. Counterfeiters take a genuine five-dollar bill, strip the ink with chemicals, and print a hundred-dollar design onto the authentic cotton-linen paper. Because the paper itself is real, the note passes the pen test and feels correct to the touch. The giveaway usually lies in the watermark and security thread, which remain those of the original five-dollar bill rather than matching the new denomination. Meanwhile, cheap digital printing continues to lower the barrier to entry for small-scale fraud, even as features like the 3D ribbon remain stubbornly difficult to reproduce.
Cash is not disappearing, and neither is the incentive to fake it, so the most useful thing you can do is build a two-second verification habit and pass it along to the people around you. Retailers who train staff on the ribbon, the watermark, and the security thread lose far less money than those who rely on a single pen, and individuals who know what to look for are far less likely to be left holding a worthless piece of paper. Learn the features on the notes you handle most often, keep a small ultraviolet light handy if you deal with large bills regularly, and take a moment to look before you tuck a hundred into your wallet.