Fuente: Wipo "digitalization" A method is disclosed for incrementally updating an existing digital map of a client device in a digital map update system. The digital map update system comprising a primary digital map update centre, a secondary digital map update centre and a plurality of remote client devices. The primary digital map update centre and the secondary digital map update centre are each able to provide a set of one or more incremental updates for communication to one or more of one of the plurality of remote client devices for use in incrementally updating existing digital maps of the client devices. The secondary digital map update centre provides data indicative of a set of one or more incremental digital map updates for communication to at least one of the plurality of remote client devices for use in incrementally updating an existing digital map of the device. The secondary digital map update centre additionally provides information relating to the set of one or more incremental digital map updates to the primary digital map update centre.