A method of synchronizing ported number data within a telecommunications network in which a number portability administration center has received a request from a subscriber having a directory number (DN) to port is provided. The method comprises the steps of: a Number Portability data manager sending a subscription request to the NPDB to receive future notifications about subscriber ports to / from specific Location Routing Number(s); the NPDB honoring these subscriptions when a user ports their DN. If this is the initial LRN assigned to the DN, then the NPDB derives the LRN of the code holder. If the LRN from which the subscriber ported has a subscription, then the NPDB sends a notification message to the NP data manager with which the LRN is associated indicating that the DN ported out. If the LRN to which the subscriber ported has a subscription, then the NPDB sends a notification message to the NP data manager with which the LRN is associated indicating that the DN ported in. The method further comprises receiving a notification message for the LRN at a number portability data manager, wherein: if the notification message indicates that a DN has ported in, then the number portability data manager sends a request to an ENUM (telephone number mapping) server to turn the entry for that DN on; and if the notification message indicates that a DN has ported out, then the number portability data manager sends requests to the ENUM server and to a subscriber database to turn the entry for that DN off.