A UE and a method for handling UE onboarding are provided. The method includes receiving a first indication, a second indication, and a third indication from a cell via a SIB1, the cell operated by one or more SNPNs; reporting, by an AS layer of the UE, the first indication, the second indication, and the third indication to a NAS layer of the UE; receiving, by the AS layer of the UE, an indication for UE onboarding from the NAS layer of the UE; and transmitting a first RRC message to the cell, the first RRC message including an onboarding request associated with the indication for UE onboarding.