Māori voters will get to choose whether to be on the general or Māori roll from next month when the Māori Electoral Option opens.
Voters of Māori descent will have from April 3 to August 2 to decide which roll to be on for the next two general elections.
The option, which is held after each Census, is important because it, along with 2018 Census data, determines the number of Māori electorates and their boundaries.
The number of Māori electorates has remained at seven for the past six general elections. There were six electorates in the 1999 election, five at the 1996 election and four in 1993.
Stats NZ estimates that for another electorate to be added, around 27,000 Māori would have to change from the general to Māori roll, or 64,000 Māori enrolling for the first time would have to go on the Māori roll, or a mix of both.
First-time voters of Māori descent, as well as Māori already enrolled to vote, can decide which roll to be on.