The 2023 census will be the first in Aotearoa New Zealand's history to collect data on gender, sexual identity and variations of sex characteristics (known as intersex status).

Other new questions include additional information on activity limitations/disability, reinstating a question on phone numbers and the number of night occupants in dwellings, Stats NZ said in a release.

Social and population insights general manager Jason Attewell said the census touches everyone and will provide a detailed picture of how people with diverse genders and sexual identities experience life in Aotearoa New Zealand.

Attewell said the data will also inform better decision-making and provision of services for the Rainbow community.

"We are already collecting sexual identity and gender in our other household surveys and that is going well. It is important that everyone is able to see themselves in – and take part in – the census."

Stats NZ said collecting information on gender and sexual identity in the census will allow more detailed geographic breakdowns of the data produced than may be possible for data collected in household surveys.

"This is exciting because for the first time we will have data about the intersex community and just how many people in Aotearoa New Zealand are part of this community," Attewell said.

Stats NZ said questions on sexual identity (for example, heterosexual, gay, or lesbian) and variations of sex characteristics will only be asked of people aged 15 years or older.

However, it was noted that if the data is not of sufficient quality, Stats NZ may not be able to release it.

Statistician and deputy chief executive for census and collections operations Simon Mason said the most important thing people can do to ensure they can release data for every question is to fill in all of their census form.

"The more answers we collect, the better the quality of the data and the more useful and usable it will be.

"We know we have a part to play too, by making the census accessible and easy for everyone to complete, and we're working hard to do this."