A control plane function node may be used in a Fifth Generation (5G) Non-Standalone (NSA) architecture having Radio Access Network (RAN) level interworking between a Long-Term Evolution (LTE) RAN and a 5G New Radio (NR). The node obtains usage report data which are based on traffic of a user equipment (UE) via primary and secondary Radio Access Technologies (RATs). The node also obtains secondary RAT usage report data which are based on traffic of the UE via the secondary RAT. The node constructs a message which indicates a request for charging based on the usage report data and the secondary RAT usage report data. In constructing the message, the node populates, in association with a corresponding rating group and usage data of the UE, an identifier of a flow or bearer associated with secondary RAT usage, together with the secondary RAT usage report data.