The present disclosure provides a method (500) in a Network Function (NF) node for subscription to notification of data change in a Unified Data Management (UDM) node. The method (500) includes: transmitting (510) to the UDM node a request for retrieval of a user subscription data or a request for registration with the UDM node, the request for retrieval or the request for registration including a callback Uniform Resource Identifier (URI) for use by the UDM node to notify the NF node of the data change; and receiving (520) from the UDM node a response to the request for retrieval or the request for registration.