Bank cashiers are trained to detect suspicious banknotes. They use their eyes and hands to look for signs of counterfeiting, such as printing smudges or blurriness, inconsistent serial numbers, uneven edges, and other irregularities.

Yes, banks in 2026 use a multi-layered approach to verify the authenticity of currency. Tellers are trained to perform manual checks using the "Feel, Look, Tilt" method, feeling for raised intaglio printing and looking for security threads or watermarks that are only visible when held to the light. However, the heavy lifting is done by high-speed currency sorting machines and UV scanners. These devices check for specific magnetic ink signatures, ultraviolet fluorescence, and micro-printing that are nearly impossible for counterfeiters to replicate perfectly. If a bank detects a fake bill, they are legally required to confiscate it—you do not get a "refund" for a counterfeit note. They then report the incident to the Secret Service (in the US) or the Central Bank (internationally) to track the source. Banks also monitor ATM deposits using similar internal sensors to flag suspicious bills immediately.