Here are some tips on how to detect it. Look for differences between the two, rather than similarities. When held up to the light, the letters USA and the denomination of the bill are noticeable. This thread, added to bills printed after 1990, is a quick reference to verify legitimacy. Examine the general look and feel of the bill.
Genuine currency is printed using the intaglio method, giving the bill a three-dimensional look.
Counterfeit bills tend to look flat. Intaglio printing gives bills an embossed, rigid texture, while counterfeit bills are generally much smoother. Although employees cannot go through this entire list of tips during each sale, making them aware of the possibility of counterfeiting might be enough to save your business from becoming a victim. Paper stock - Look for red and blue fibers embedded in the paper. Look for significant detail in crosshatch latticework.