A comprehensive real estate lockbox system (10) which provides a variety of operational features. Some of these features include the ability to : record all accesses to all lockboxes (12); transfer all or part of such records from the lockboxes (12) to a supervising real estate agency or board; organize and review such records; facilitate operation of lockboxes (12) that are mounted in awkward or poorly lit locations; limit lockbox accesses to preselected agents, agencies or boards; reprogram lockboxes in the field; monitor redundantly the status of the lockbox battery (32); record diagnostic information on each operation of a lockbox (12) or key (14); render keys inoperative on predetermined dates; disable unauthorized keys; grant agents from remote real estate boards permission to open certain lockboxes, and; grant different keys different privileges.