Explainer: Did you know not enrolling to vote is against the law?

"There is a penalty but it's not just a matter of being unenrolled," said Karl Le Quesne, chief electoral officer for the Electoral Commission.

"It's an offence if a person knowingly or wilfully fails to apply to enrol - in other words really digs in their heels and refuses to enrol."

The Electoral Commission would much rather you just enrol, please.

"We're not aware of anyone being prosecuted for refusing to enrol," Le Quesne said.

"The Electoral Commission does not have the power to fine or prosecute anyone. We would need to refer a matter to police. It would be up to the police to decide whether any action is taken."

The courts also aren't likely to make a big deal of not being enrolled to vote.

"Enforcement of this measure requires a police prosecution in the District Court and I do not know of this ever occurring," said University of Otago law professor Andrew Geddis.

"I suspect the police have somewhat more urgent matters to attend to."

It has been compulsory to enrol in general electorates since 1924, and in the Māori electorates since 1956.

"The idea behind compulsory enrolment is that it is reasonable, in the interests of facilitating a healthy democracy, for the law to require those eligible to enrol," Geddis said.

"Making enrolment compulsory helps ensure the electoral roll is accurate and complete, which enables electoral officials to administer elections and to prevent and detect electoral manipulation."

Consider the law more of a friendly reminder, perhaps.

"The law effectively works more as a prompt to civic duty rather than a stick with which to beat people who fail to comply," Geddis said.

Actually, no.

"Enrolment is compulsory, but voting is not," Le Quesne said.

"Compulsory voting would then change voting from being a right, which people may or may not exercise, to a civic duty," Geddis said.

Across the ditch, it is mandatory to vote in Australia, where turnout typically runs about 90 percent for the last several federal elections. By comparison, 77.51 percent of those enrolled voted in our 2023 general election, according to the Electoral Commission.

An Independent Electoral Review conducted by the previous government was released in 2023, and recommended keeping compulsory enrolment on the books. It also looked at the lack of enforcement of that rule.

"There are good reasons for not strictly enforcing compulsory enrolment, including that strict enforcement may negatively impact people's experience of the electoral system," the report found.

That panel also looked at whether compulsory voting should be introduced as in Australia, but said it ultimately considered "that requiring people to vote may be a step too far, as it constrains freedom of choice."

As of this election, you can no longer enrol to vote all the way up to Election Day.

You must be registered no later than midnight, Sunday 25 October.

• Read more: Explainer: Why you need to enrol to vote by 25 October.

However, it's even better to enrol by this coming Sunday, 4 October, which is Writ Day, as if you enrol after that date and before 25 October, your vote will be considered a "special vote".

Special votes are by anyone who isn't on the printed electoral roll, lives overseas or votes outside their elecorate or away from a polling place because they can't get to one.

There were concerns in last year's Auckland local body elections about thousands of special votes being disqualified due to incorrect or missing declaration details, or outdated enrolment details.

How to enrol to vote:

• Online: Visit the Electoral Commission website and put in your details.
• Phone: Call 0800 36 76 56 to get an enrolment form sent to you in the mail.
• Text: Text your name and address to 3676 to get a form sent to you in the mail. Calls and texts are free.

As of Tuesday morning, the overall enrolment rate was 91 percent, but for young people aged 18 to 24 it was just under 61 percent.

Again, nobody is likely going to get hauled off by the law over it, but enrolling to vote actually is the law if you're over 18.

"We'd like it to be a lot higher," Le Quesne told Morning Report.

The electoral roll isn't just a list of who's enrolled to vote. It's also an important data resource.

"Beyond allowing people to vote at national and local elections, the electoral roll is very useful to Government for a range of reasons," Geddis said.

"It is used for jury selection, political campaigning purposes, and health and social science research."

The electoral roll contains your full name and home address and can be viewed at public libraries or Electoral Commission offices, and is also available for purchase.

"We do not release your date of birth, phone numbers or email address to the public," the commission says on its website.

But some of the information given to the roll can be released to other groups.

"The law requires us to give lists of people who are enrolled to vote on the published electoral rolls to certain people and organisations when they ask for them," Le Quesne said.

"These lists may have your personal information on them. This includes information that's not publicly available on the electoral rolls, such as date of birth or the age range you're in and whether you're of Māori descent."

However, there's also an unpublished roll you can request to be put on, which keeps all details private.

Information can be given to local councils for their elections, the Ministry of Justice for jury lists, Stats NZ and other organisations for research.

Political parties, candidates and MPs can also ask for lists of people who are enrolled for campaign uses - but the commission does not give out phone numbers or email addresses to them.