A communications system is arranged to provide a service to user equipment in accordance with mobility management information. The system comprises a session protocol server (S-CSCF) operable to control the state of a communications session for at least one user equipment in accordance with user profile data, a subscriber information database (HSS) for providing the user profile data for the session protocol server (S-CSCF), and a mobility server. The mobility server comprises a mobility manager operable to receive mobile dependent evaluation reports providing an indication of a current state for communicating with the user equipment and to form the mobility management information based on the evaluation reports. The mobility server includes an application programmer's interface operable to communicate call control signalling data between the mobility manager and the session protocol server (S-CSCF). The mobility manager is operable to notify the application program providing the service to the user equipment of the mobility management information in response to a subscription for the information from the application program, the subscription being provided via the session protocol server (S-CSCF) using the call control signalling data. By integrating the mobility server within the system, mobility management information provided by the mobility server can be integrated with other services provided by the system. As such, mobile users deploying application programs within the system, which subscribe to the mobility server, can benefit from added value provided by established system components and re-using established interfaces.