More than 102,000 voting papers are on their way to Tauranga and Bay of Plenty residents as the nation pauses to consider five alternatives to the current flag.
Voting enrolments closed on Thursday and the voting papers started to arrive in mailboxes from Friday and the last papers will be received on November 27.
Nationwide more than 3 million New Zealanders will be eligible to vote in the first referendum on New Zealand flag as it gets under way.
As at October 31 there were 51,074 people registered to vote in the Tauranga electorate and another 51,451 on the Bay of Plenty electorate roll.
Enrolment papers received by the Electoral Commission after this date were still being processed, a commission spokesperson said.
Voters should get their voting papers by November 27.
"Look out for your voting paper in the mail over the next few days," chief electoral officer Robert Peden said.
"Your voting pack will include your voting paper, a return freepost envelope, full information on how to complete your paper, and information about the five flag options."
The big question being asked of voters is - If the New Zealand flag changes, which flag would you prefer?
Eligible voters are asked to rank the five alternative flag designs selected through the Flag Consideration Process from those suggested by the public.
"On your voting paper, you will be asked to rank the alternative flag options - 1, 2, 3, 4, 5 - in the order you prefer them," Mr Peden said.
"Write a 1 in the box of the flag option you prefer most. Put a 2 in the box of the option you prefer next, and so on. You can rank as many or as few flag options as you wish, but you shouldn't skip a number or use the same number more than once."
Mr Peden said if one flag option gets 50 per cent or more of all the first preference votes it would be selected on the first count.
"If no flag option gets 50 per cent or more of the first preference votes, the flag with the fewest number one votes is dropped and its votes go to the flag each voter ranked next.
Mr Peden said this process continued until one flag got 50 per cent or more of the valid votes.
Voting papers should be posted into a NZ Post mailbox by December 8 to ensure they arrived back at the Electoral Commission offices by the December 11 deadline.
In March 2016, there will be another referendum to choose between the most preferred option from the first referendum and the current New Zealand flag.