Abstract: A multi-mode mobile terminal having a subscriber identity is provided which uses knowledge of communications network supported service levels to navigate to a communication mode allowing the greatest possible service availability when the subscriber identity in at least one of the network modes is invalid. The mobile terminal may not only provide the ability to switch communication service from a current mode to an alternative mode to process emergency calls but may also restrict user operations on a communications network based on the services available without a valid subscriber identity. Operations of the mobile terminal invention may be supported by service level information on various communication service providers contained in memory within the mobile terminal or be obtained by the mobile terminal from the networks.