Disclosed herein are methods and apparatus for a key system module which enables a presentable key system on devices provisioned with softphone and embedded voice applications. A method includes provisioning a key system module for operation with the softphone to enable the key system, establishing, by the softphone application using a service provider Internet Protocol (IP) telephony server, a non-shared line association with the key system, establishing, by the softphone application using the service provider IP telephony server, associations with key lines in the key system, receiving, from the service provider IP telephony server, key line statuses, generating, by the key system module, a key line user interface based on at least the statuses of the key lines, and presenting, by the softphone application and the key system module on a device associated with the softphone client, the key line user interface with the key lines in the key system.