The details of an apparatus and method of uplink data during cell update in universal mobile telecommunications system user equipment are disclosed herein. According to one aspect of the present application, there is provided a user equipment to send uplink data to a UTRAN during a CELL UPDATE. The apparatus has an uplink data saving RRC with an uplink data store to save the uplink data while the CELL UPDATE procedure is ongoing, and a state machine having a Cell FACH state and/or a Cell DCH state. The uplink data saving RRC sends the saved uplink data to the UTRAN via an UPLINK DIRECT TRANSFER when the CELL UPDATE procedure has completed and the state machine enters either Cell FACH or Cell DCH state. According to another aspect of the present application, there is provided a method of sending uplink data to a UTRAN during a CELL UPDATE procedure. The method includes the steps of saving the uplink data while the CELL UPDATE procedure is ongoing and sending the saved uplink data to the UTRAN via an UPLINK DIRECT TRANSFER when the CELL UPDATE procedure is completed and the user equipment is in one of CELL FACH and CELL DCH state.