An item drop box sensor system for detecting items deposited within a drop box may be configured to detect movement of an item deposit tray and to detect items deposited within the drop box. The drop box sensor system may comprise one or more tray movement sensors for detecting movement of the deposit tray, one or more item detection sensors configured to detect items passing into the drop box via the deposit tray, and an onboard controller for selectively activating the various sensors to conserve power and for transmitting data indicative of the status of the drop box to a central server configured for scheduling item pickups for various geographically spaced drop boxes.