Abstract: A showing management system for programmatically matching a specific electronic lockbox with a specific Listing ID, whereby lockbox access data from an electronic lockbox are matched with showing appointment records maintained in the showing management system to complete the lockbox access records when the Listing ID for a particular showing appointment is missing from the lockbox access record. The disclosed methods and algorithms are also applied to programmatically verify a manual assignment of a lockbox, to a real property, utilizing a showing management system.