There are two ways to detect counterfeit money: 1) by looking at the physical characteristics of the bill, and 2) by scanning the bill through a special lamp designed to detect fake currency.

How To Detect Counterfeit Money Through Physical Inspection

Counterfeiters may be able to copy one or two security features but definitely not all eight of them. If you know how to check these eight features, you should be able to quickly spot a fake bill.

Color Shifting Ink

All denominations of $5 and above that were released since 1996 have this security feature. Under UV light, an authentic bill will glow in its correct color.

  • $5 – glows blue

  • $10 – glows orange

  • $20 – glows green

  • $50 – glows yellow

  • $100 – glows pink

Raised Printing

An authentic U.S. reserve note should not be smooth. Raised printing can be detected by running your fingernail down the collar/jacket. You should feel an unsmooth texture from the ridges.

Blurry Lines

Authentic bills are extremely detailed, with super fine lines created by die-cut printing plates. Printers that are often used by counterfeiters often lack this sophistication, making it impossible to duplicate the quality of micro-printing.

Red and Blue Threads

An authentic bill will have tiny red and blue threads woven within the fabric. Counterfeiters try to mimic this by printing similar red and blue patterns on the surface of the bill.


The watermark is usually a hologram of the face on the bill. It is located in an unprinted space to the right of the portrait and can be seen from both sides of the bill.

  • The watermark will be visible when you hold the bill up to the light

  • The watermark is not printed on the bill but embedded in the paper

  • The watermark face should match the face on the bill


Security Thread

The security thread is a vertical strip that runs from top to bottom, featuring a micro-printed text spelling out the denomination. For example: on the $5 bill, "USA FIVE" is written on the security thread.

Security Ribbon On New $100 Bills

The Department of Treasury has added an extra security feature on the new $100 bill. Down the right middle is a visible 3D security ribbon in blue color.

Serial Numbers and Printing Series

Make sure the serial number matches the series and year the bill was printed. The first letter of the serial number corresponds to a specific year.

How to Spot Fake Money through Counterfeit Detection Tools

Counterfeit money detectors come in a wide range of styles and prices. Here are some of the most common types, listed from the cheapest and most unreliable to the most accurate and expensive.

Counterfeit Pens

For around $5, you can purchase a counterfeit money pen. Fake bills are made of wood-based paper. The iodine solution on the pen will react with the starch on the paper and leave a dark mark. Authentic bills are made of fiber-based paper so there won't be any marks.

With the arrival of digital printing, counterfeiters have found a way to treat fake bills so they can pass the pen test.

Ultraviolet Lamps

This type of lamp shines ultraviolet light on the bill to verify its UV marks. These images are made of dye that is only visible under UV light.

Watermark Lamps

Watermark lamps are specially designed with light that is capable of displaying watermarks that are invisible to the naked eye.

Magnetic Ink Scanners

These counterfeit money detectors identify the magnetic ink and metal threads located on different areas of a banknote.

Multi-Test Scanners

State-of-the-art counterfeit money detectors are the best way to eliminate fraudulent bills. These machines are fitted with advanced imaging software that can detect multiple security features – including the exact dimensions of a banknote – with 100% accuracy. Any fake bill will automatically be rejected.

Protect your business from financial loss by purchasing a counterfeit money detector and teaching your employees how to check for fake currency. Here at Self Defense Superstore, we have what you need. Browse our products today!