Embodiments are directed to an inventory system that comprises sensors coupled with an inventory holder and a management module to automatically determine a location of an interaction with an inventory bin of the inventory holder by an inventory item without requiring hand-scanners. The system may determine the location of the interaction with which to associate to a particular bin of the inventory holder based on signal information provided by one or more proximity sensors coupled with the inventory bins of the inventory holder. The system may update information to associate the inventory item with the location of the particular bin in the inventory holder in response to determining the location of the interaction using the signal information.