Australians have less than two weeks to register for the same-sex marriage postal vote.
Those who are not already registered on the electoral roll, or who need to update their details, have until August 24 to correctly enrol with the Australian Electoral Commission (AEC).
Everyone registered on the electoral roll by that date will have the ballot paper sent out to them by September 12.
They will have until November 7 to send them back, with the result announced on November 25.
The postal vote is not compulsory, and is non-binding for politicians. Parliament will have a chance to vote on the issue later this year, but there is no guarantee that will happen.
For citizens overseas, only those who have registered an overseas address will be able to vote. You can enrol to vote or update your details through the AEC website.