Since December, no less than 30,000 Banknote Watch posters have been sent out to Police Crime Reduction Officers for distribution in every High Street. The message to retailers on those posters?
"A stained note is probably a stolen note".

There are now heightened concerns that stained notes may not be detected by sorting and changing machines. As a result, the Banknote Watch scheme organisers have encouraged the formation of a partnership between chemists supplying cash-degrading substances and the banknote-validator engineers.

Cash degrading systems are used widely wherever cash is stored or carried – rendering it unusable in the event of a robbery. The aim is to achieve a means of automatically detecting the stained notes so that they can be used for gathering criminal intelligence, to prevent them from being re-issued and put a stop to any money laundering via change machines. The Banknote Watch Working Group reports to the BSIA's Cash and Property Marking Section as well as the Transport Section, the Bank of England, the British Bankers' Association and the Association for Payment Clearing Services.