Subband based uplink access for new radio (NR) shared spectrum (NR-SS) is disclosed. A base station performs a listen before talk (LBT) procedure on system allocated subbands of a shared communication channel. The base station determines a first set of candidate subbands that are signaled to a user equipment (UE). The UE performs an LBT procedure on the first set to identify a second set of candidate subbands including the successful LBT subbands of the first set. Aspects of the disclosure provide for managing and refining the subbands for transmissions. A first aspect provides the UE to determine a transmission behavior based on mismatch between the first and second sets. A second aspect provides the first and second sets in handshaking between the base station and UE for refining the eventual transmission set of subbands. A third aspect provides cross-band LBT reporting for further refining subband selection in later slots.