A communication method and apparatus, where the method includes: a session management network element sending location area information; a mobility management network element receiving the location area information from the session management network element; obtaining location information of a terminal; determining, based on the location area information and the location information, that the terminal is located outside a service area indicated by the location area information; and in response to the determination, sending, to the session management network element, a message for triggering update of a session management information.