This application provides a reflective QoS flow characteristic-based communications method and apparatus. In the method, an access-network network element sends first information to a core-network network element, where the first information is used to indicate whether a data packet has a reflective QoS flow characteristic; and the access-network network element determines, based on the first information, whether there is a need to send a QoS flow identifier to a terminal. In this way, signaling overheads are reduced.