Abstract: A method and system for automatically updating subscriber service accounts to accommodate a numbering plan change, such as an NPA split, is provided. Subscriber service account information, such as account information pertaining to speed dialing, is automatically updated by a subscriber account update process, which runs periodically on an administrative computer system connected to an ISN via a wide area network. The subscriber account update process accesses NPA split tables to determine pending NPA splits. For each pending NPA split, the update process determines impacted ANIs that have existing service accounts. Then, for each such impacted ANI, the update process creates a new service account, which is indexed by the new ANI, to which the impacted ANI is being converted. The new service account includes account information previously stored in the existing account. The existing account is updated to refer to the new account.