After months of debate Australia will find out if same-sex marriage gets a Yes or No tomorrow, following a controversial postal survey on the issue.

Voters had until November 7 to get their ballot to the Australian Bureau of Statistics office with early indications showing that as many as 12.6 million Australians voted in the survey.

The ABS has been busily tallying the results with the final outcome and here is all you need to know about the big reveal and what happens next.

When will the result be announced?

After long campaigns on both sides, Australian Bureau of Statistics’ David Kalisch will reveal the answer to the $123 million question at 7am (AWST) on Wednesday in Canberra.

Following the announcement official statistics will be released to include a count of Yes, No and response not clear (informal vote)

There will also be a breakdown nationally and by Federal Electorate and state/territory. There will also be participation rates by age and gender for each.

According to the ABS however, with the vote being anonymous there will not be a breakdown of response for age and/or gender.

Where can I watch the result?

The results will be posted on the ABS website here and will be live streamed by most television networks from 7am.

A number of events have also been organised across the country to watch the results roll in, with the Yes campaign scheduling an event in Northbridge.

The Equality Campaign has invited people to head to the free event at Northbridge Piazza to watch the result on the big screen from 6.30am.

What happens if it’s Yes?

The survey is advisory and not binding. In other words, politicians can still ultimately vote against the outcome. The government can still vote "no" if Australia votes "yes".

However if the vote is yes, it appears the Senate or the House of Representatives will debate one of two proposed bills on same-sex marriage.

The first, which has yet to be tabled to the Senate, by Liberal WA Senator Dean Smith, and a second from conservative MPs who have proposed bill which would allow businesses to refuse to provide services to gay weddings.

The Yes campaign has raised major concerns about a second bill to legalise gay marriage that was made public by Liberal senator James Paterson on the weekend.

It has been widely criticised with the nation’s peak legal advisory body warning it would wind back anti-discrimination laws.

What happens if it’s a No?

If the survey produces a no vote, the government has pledged to block any legislation for same-sex marriage, and that is not likely to change unless Labor comes into power.

Labor has promised to legalise same-sex marriage in its first 100 days in government, in the event of a No result, if it were to be elected.