The Herald reports the online system can only handle 200,000 an hour so there may be some delays today.
The census data will be used for all sorts of decisions in the future, such as population funding. One use of it also wil be in deciding electorate boundaries.
The law basically states there will be 16 South Island electorates. Their average population is used to calculate the number of North Island electorate and Maori electorates. There are currently 16, 47 and 7 respectively.
We won’t know until the census is done, and the Maori option is done, but there could be up to three new North Island electorates and one new Maori electorate. If so, that would mean 74 electorate MPs after the next election and 46 (down from a target of 50) List MPs.