A method, an apparatus, and a computer program product to support sub-PRB allocation on the Physical Uplink Shared Channel in a wireless communications system, a new resource allocation method is described, where available physical resource blocks (PRBs) in each subframe or narrowband are reorganized into a number of sub-PRBs, which would apply to user equipment in both in CE Mode A and CE Mode B while also supporting sub-PRB allocation in Msg3 as part of early data transmission during random access, so that a user equipment, which is previously configured for using physical uplink shared channel sub-PRB resources, upon receiving an indication, will then use or determine whether to use a sub-PRB resource allocation based on the received indication.