A method of updating a cash register system (10) including a cash register program (1) configured to interact with at least one cash register peripheral (4) under the control of a control module (5). The method includes a step of inspection, at the control module (5), of the interactions between the cash register program (1) and the at least one cash register peripheral (4); a step of processing at least one inspected interaction, the processing step being selected from within the group including the reformulation of an interaction, the modification of an interaction, the copying of an interaction, the extraction of data from an interaction, the reorientation of an interaction.