Abstract: A cash handling machine comprising: a cash handling mechanism for receiving physical articles including cash, sensing equipment for sensing the articles, processing equipment processors, and memory storing code arranged to run on the processing equipment. The code comprises multiple neural networks arranged in a series ordered from first to last, each trained to classify which of a respective set of classes the articles belong to based on the sensed data. The set of classes of each respective neural network comprises a different respective subset of one or more respective recognized classes classifying a respective one or more types of cash recognised by the respective neural network, and further comprising an unrecognized class into which all other articles other than the respective recognized types are classified. For each article, the code starts with the first neural network in the series, using each network in turn to try to recognize the article.