NICTA CEO Charles Punaha has announced this in Port Moresby.
He said the deactivation process will commence this Wednesday in all provincial centres, with a final list to be announced later in the week.
He also announced the extensions to rural areas in the country so that telco providers may be able to continue registrations in remote areas.
Telco providers say the deactivation process will not affect people from rural areas travelling into main provincial centres as they are able to monitor SIMs used in a locality.
Telco providers have yet to fully register their client base with both Digicel PNG and Telikom only having registered just over 54 percent, while bmobile-vodafone has registered around 75 percent.
They will each be issuing separate statements on the status of their registration process.
Punaha has urged those in the main centres who have not registered to do so before close of business today.