The candidates are split on their views about Māori seats. Dimery, Douglas, Hoff-Nielsen (Ngāpuhi) and Toner are in favour with Archer, Christie and Bell against.
Powdrell (Tainui) would not be drawn on whether or not he was in favour of the option.
Postal voting documents will be mailed to eligible voters from January 26 with voting closing on February 17. Nominations closed on Tuesday.
"All resident electors and non-resident ratepayer electors of the Whangārei urban constituency whose names are on the latest electoral roll are eligible to vote," Ofsoske said.
There are 29,300 people eligible to vote in the constituency.
The successful candidate will join sitting NRC Whangārei urban councillor Jack Craw.
Bell, Christie, Tana Hoff-Nielsen and Toner live in the Whangārei urban constituency. (Douglas lives in Whangārei but not in the constituency where the byelection's taking place).
A number of the candidates have previously been Northland local government councillors.
Powdrell wouldn't be drawn on Māori seats, saying this was because he wasn't in favour of the first past the post voting system under which they existed. His preference was for a single transferable voting system.