A method and apparatus is disclosed for dynamically switching an operating address book upon registering a migrating radio with a visited network. Prior to migrating, the radio uses a first address book in a home network to identify calling radios in the home network, wherein the first address book includes information associated with radios in the home network. Upon roaming to a visited network, the radio registers with the visited network and the radio retrieves an additional network specific address book for the visited network. The radio automatically switches to the additional network specific address book, upon registering with the visited network. Subsequent calls received by the radio are thereafter identified according to information stored in the additional network specific address book.