A referendum is a national vote on a question about a proposed change to the Constitution.

All Australian citizens aged 18 and over must vote.

It’s been quite a while since we held a referendum – the last was over 20 years ago in 1999.

Learn more about how they work…

Federal Parliament decides on the proposed change to the Constitution to put to voters. A proposed law outlining the changes to the Constitution must be passed by both houses of Parliament - or passed twice in either the House of Representatives or the Senate.

A referendum must then be held no sooner than two months and no later than six months after the bill has passed Parliament.

How a referendum proposal is decided

  • The Governor-General issues a writ (the formal instruction to run the referendum) which, like an election, must be held on a Saturday.
  • A referendum can be held at the same time as a federal election but can also be held as a stand-alone event.
  • There can be a single referendum question or several proposed changes to the Constitution for voters to consider at the same time.


While Chapter 8 of the Constitution provides key rules for the conduct of a Referendum, the Referendum (Machinery Provisions) Act 1984 outlines specific processes the Government must follow when holding a referendum.

How the vote is conducted

The proposed change to the Constitution must be approved by a ‘double majority’ – that is:

  • a national majority of voters (more than 50%) from all states and territories, and
  • a majority of voters (more than 50%) in a majority of states (at least four of the six states).

The result is binding. This means the Australian Government must act on what voters decide.


While the votes of people living in the Australian Capital Territory and Northern Territory count towards the national majority only, all vote totals will be communicated for information through the AEC’s tally room by state and territory, by electoral division and by polling place.

Is it all counted on the night?

No, this isn’t possible. The access provided to people to vote away from their home division or state/territory, internationally or by post means votes take time to travel back to the appropriate AEC counting centre. While the count itself is easier than a federal election (formal vs informal, yes vs no), there are still logistical considerations that mean a clear indication of a final result may take days or even weeks.

In addition, just like a federal election, every vote will be counted more than once to check that the initial count was correct (a process called fresh scrutiny) and all counting happens in front of party-appointed scrutineers.

Once the counting process is finished the AEC will return the writ (the formal instruction to run the referendum) to the Governor-General with a certificate from the Electoral Commissioner setting out the result of the vote for each state and territory and nationally.

If the referendum is approved by a double majority of Australian voters, this is the final step in approving the Bill setting out the changes to the Constitution that was passed by federal Parliament. This Bill will be presented to the Governor-General for assent. An Act to change the Constitution comes into operation on the day the approved Bill (Act) on which the approved Bill (Act) receives assent unless the Act itself says something different.

If the referendum is not passed by a double majority of Australian voters, the Bill previously passed by Parliament setting out the proposed changes to the Constitution is not approved and can’t be presented to the Governor-General for assent.

The AEC is the independent statutory authority responsible for running a referendum. We’ll communicate with voters about their requirement to participate, the purpose of referendums and voting options.

There is freedom of political communication and while the AEC will be active in ensuring accurate information is available about the referendum processes we operate, it’s not our role to comment on campaign communication about the referendum topic

The AEC's role