BREAKING IT DOWN: Exactly what you need to know about the postal vote.

What exactly is a postal vote?

This postal vote will be used to gauge public opinion regarding if same-sex couples should be able to marry in Australia. This vote is not compulsory and not binding. It will be run by the Australian Bureau of Statistics (ABS).

How do I know if I am registered to vote?

If you registered yourself in the Australian Electoral Commission’s (AEC) electoral roll for the last Federal or State election, and you have not changed your address since, then you are automatically registered. However, if your address is no longer the same, then you must change your details in the AEC.

As of March 2017, there is nearly 14% of those aged below 25 missing from the electoral roll and about 800,000 overall.

If you have just turned 18, and this is your first vote, then you must enrol to vote. If you are currently 17, but will be 18 by September 12, then you can still enrol.

How do I post a letter?

Many young people eligible to vote may have never even posted a letter before. Don’t fear though, all this information will be provided when you receive the ballot form.

What are the important dates that I need to know?

August 24 – you have until August 24 to register with the AEC or to change your address.

September 12 – the first letters will be received to those registered in the electoral commission.

November 7 – you have until this date to post the letters back. That gives you just over three weeks to complete the vote and put it in the mailbox.

November 15 – the result from the postal vote is expected to be announced.

What if I am overseas at the time of the postal vote?

You can still vote.

All you need to do is tell the Australian Electoral Commission that you will be overseas at the time and provide them with an address for them to send you the form. You can do that here.

Can I vote online?

No. There is no online component. It will all be done via the post.

According to SBS, Labor's Sam Dastyari said, "Why on earth are we not opening this up to the internet? Let's not kid ourselves. That is how [young Australians] participate in politics."

If the majority of Australians say 'yes', will same-sex marriage be immediately legalised?

No, this vote is not binding.

However, the government has committed to a private members bill if the majority of Australian's vote 'yes'.

Prime Minister Malcolm Turnbull  has said that his government "will not facilitate the introduction of a private member's bill on this matter unless the Australian people have given their support through a 'yes' vote through this national vote that we are now undertaking."

If the private members bill is proposed, MPs will then get a free vote on the bill.

What has the turnout been like for previous postal votes?

Compulsory voting is the norm for Australia so it is unusual that a voluntary postal vote occurs.

The last postal vote at the federal level was in 1997 and concerned whether or not Australia should become a republic.

Overall, 46.9% of Australians voted.

Out of those aged 18-25, one third participated; which was the lowest participation rate over all age groups. The participation rate increased with each age group. Nearly 60% of those aged over 55 took part.

LISTEN: A message for Malcolm Turnbull about the same-sex marriage plebiscite...

If you are unsure if you are enrolled or not, you can check here.

If you need to enrol, click here.