An optional PBX interface for a property management system (PMS), which is an application software system intended for the hospitality industry, which includes hotels and motels, dormitories, cruise ships, hospitals, and extended care facilities such as nursing homes and retirement homes. PMI allows the coordination of front office and back office management features with PBX communications functions. For example, a housekeeper can use the telephone in the guest room to indicate room status, such as "clean and ready for occupancy." Front desk personnel can disable a guest telephone when a room is vacant, or if the guest's credit card has been rejected. Charges for calls through the PBX can be associated with the guest account and a single, all-inclusive bill can be rendered.