The commission printed one million training materials.
The 2023 population and housing census earlier scheduled for March 29 was shifted to May 3-7 by Mr Buhari.
The 2006 census pegged Nigeria’s population at 140 million.
A staff of the Commission and Comptroller of Chanchaga LGA, Niger State, Sanusi Maigida, had earlier claimed that the NPC server was hacked.
The federal commissioner in charge of Ebonyi, Darlington Okereke, stated this at a news conference on the training of the participants on Wednesday in Abakaliki.
NPC has reaffirmed its commitment to conducting a credible and reliable population and housing census in 2023.
A Bank Report projected that the number of poor Nigerians has increased by 14.7 per cent over the last four years and could hit 95.1 by year end.
An NPC commissioner said 7,718 enumeration areas have been selected for the trial census ahead of 2023.
