Objective Document the use of ultraviolet watermark in counterfeit joint New York City/New York State cigarette tax stamps to assess the scale at which distributors of illegal cigarettes adapt to measures protecting the integrity of the system of tobacco tax collection.

Methods In 2016, we collected 2357 empty discarded cigarette packs along a stratified random sample of block groups in New York City (n=114) and analysed 449 joint New York City/New York State tax stamps using long wave ultraviolet irradiation, light microscopy and taggant testers developed by the tax stamp manufacturer, Meyercord Revenue, to determine whether the tax stamps were counterfeit and how they differed from their genuine equivalent.

Findings 23% (n=102) of the joint NYC/NYS tax stamps examined were counterfeit. Subsequent investigation revealed that almost two-thirds (n=58) of the counterfeit sample bore ultraviolet watermark that closely resembled genuine tax stamps in terms of fluorescence, watermark colour and wording. However, microscopic findings revealed that counterfeit tax stamps mismatched the genuine ultraviolet watermark in regards to font style and word orientation.

Conclusion Counterfeiters are using ultraviolet watermarks which makes it difficult to differentiate counterfeit joint New York City/New York State tax stamps from their genuine equivalent when UV irradiation is used as the sole screening tool. Innovations in counterfeiting technology may be the result of fluorescent ink being available for purchase in the mainstream market. Independent monitoring of trends in the illicit market for tobacco products is advised to keep apace of counterfeiting methods.