Abstract: A system and method is provided for using an application operating on a smartphone and a network-connected host to book a reservation for a rental unit having a plurality of smart locking devices and to control the devices during said user's stay, where different devices are associated with different network-connected services. In one embodiment, the host is configured to identify the devices, identify corresponding services, acquire access code requirements for the same, generate a compliant access code, and provide the access code to the user and the smart service/device, along with reservation information. Not only will this allow the smart service and/or device to prepare for the user's visit (programming the smart device so that the access code works during the user's stay), but it will provide the user with a single access code that works on all smart locking devices during the user's stay.