Banknote circulation is becoming increasingly automated, with sensors playing an important role in the cash cycle. From small tabletop devices to complex industrial note inspection solutions, sensors deliver the data for banknote counting, authentication and fitness sorting. Their performance and reliability are vital for the detection of counterfeits and unfit notes, and they are key to maintaining a consistent fitness level of the banknotes in circulation. The result is a high level of trust in banknotes and the cash cycle. Inadequate sensors could create havoc.This presentation looks at the role of sensors in the cash cycle: What are installed sensors capable of today, and what are their limitations? What impact do sensors have on the selection of machine readable features, note design & specification, to ensure efficient and trustworthy note circulation?