Uplink reporting and logical channel prioritization in multiflow operation is described. In some embodiments, uplink reporting for multiflow operation utilizes bearer level splitting where the UE associates bearers or logical channel groups (LCGs) with cells for uplink reporting. In some embodiments, uplink reporting for multiflow operation utilizes packet level splitting where the UE groups buffers for all LCGs into a common pool for uplink reporting. In packet level splitting embodiments, the UE may perform uplink reporting based on the total amount of data available for transmission in the common buffer pool or by applying scaling coefficients associated with the serving cells. Some embodiments manage mapping of logical channel payloads to uplink grants for multiflow operation.