While in an inactive state, a user equipment (UE) device transmits a message to a base station. The message indicates the UE device's intent to perform transmission and/or reception of user data with the network during the inactive state. The message may include a portion of the user data and/or a buffer status report. The UE device receives a response message that induces a state transition in the UE device. Different state transitions (e.g., to idle, inactive, legacy inactive, connected) may be induced by different types of response message (e.g., release, release with suspend configuration, resume, setup). One particular type of response message causes the UE to stay in the inactive state and enables subsequent user data transmission/reception in the inactive state. The response message may implicitly (or explicitly) indicate that forwarding of the user data to a core network was successful.