Banks would start tracking notes if they had some reason to, but they don't. Getting big companies to coordinate to do something new is extremely hard. Bank n

Banks would start tracking notes if they had some reason to, but they don't. Getting big companies to coordinate to do something new is extremely hard. Bank note serial numbers are used today, to estimate the average lifespan of a note (a 5 pound note has around a 6 month lifespan on average IIRC). And something like 95% of 20 pound notes have traces of cocaine on them.