A system and method that allows mobile device applications to receive changes in registration status from application services that are accessed via an Internet Protocol Multimedia Subsystem (IMS). Applications on a mobile device subscribe to receive notifications of changes in registration status for requested services. When a change to the registration status of a service occurs, a notification message is transmitted to the application on the mobile device. Notifications of changes in status are thereby received by each application on a per-application-service basis. In some embodiments, when a request to register with an application service fails, the corresponding notification message includes a reason for the failure. In some embodiments, notification messages are originated by a registration manager that operates in the IMS and transmitted to an IMS client operating on a mobile device. In some embodiments, notification messages are originated by each application service and transmitted directly to subscribed applications.