Read more: Head of Stats NZ has told MPs that one in seven Kiwis did not properly complete the Census
This comes after MacPherson had been threatened with contempt of Parliament if she did not deliver the Census information to MPs by yesterday.
According to Stats NZ's interim calculations, roughly 10 per cent of New Zealanders didn't properly fill out their Census forms – constituting what would be the lowest participation of the past five surveys.
MacPherson said 460,000 people did not complete the Census and roughly 240,000 people only partially completed it.
This Census was the first to be completed online and it has taken longer than in previous years for the information to be reported back to the public.
The National Party's state services spokesman, Dr Nick Smith, said the fact so many people did not fill in the Census was problematic when it comes to Budget allocations.
"This leaves a huge data hole that will create problems for years in allocating tens of billions of dollars in funding for central state services like health and education, as well as affecting electorate numbers and boundaries for Election 2020."
Smith said the problems with Census 2018 were so bad consideration should be given to deferring the electoral boundary changes for 2020 and bringing forward the next Census to 2021.