But thousands of same-sex couples will find themselves already married under Australian law as soon as the Governor-General signs off on the legislation.

The bill currently before the Parliament erases the ban on recognition of same-sex marriages solemnised overseas, and will apply retrospectively.

The Equality Campaign estimates thousands of Australian couples have already tied the knot in countries such as Britain, Canada and the Netherlands, where same-sex marriage has been legal since 2001.

Almost 1000 Australian couples have taken advantage of New Zealand's decision to change its law in 2013 by marrying across the ditch.

Braidwood couple Kristy and Jo Moyle are among these.

The wedding and proposal took the form of a surprise trip to New Zealand.

Jo proposed on their first night in Auckland, the pair registered their intent to marry, to fulfill the required waiting period, before travelling around the country.

Yes! Braidwood residents celebrate results

While visiting the north island, they realised they had a deadline. They needed to find two witnesses, within 24 hours, in Aukland, which was four hours away.

At a restaurant at the time, Kristy and Jo asked the woman at the front of house if she knew anyone in Aukland who might be a willing witness, only to have her, the chef and another women step up to say they would take the next day off to drive to Aukland and witness the ceremony.

“We had a pretty administrative type ceremony, but it was really beautiful, because we made these three lifelong friends,” Kristy said.

Since the 2013 wedding the pair have had a daughter, Indigo. With the pressures a toddler puts on any relationship, the pair have been glad of the binding commitment of marriage.

“For me it represented a really important binding social contract, and actually affords you a sense of protection and stability and safeguards the work you do,” Kristy said.

While the two women can register their relationship in NSW, section 88EA of the Commonwealth Marriage Act declares same-sex unions solemnised overseas "must not be recognised as a marriage in Australia".

That ban will be lifted automatically when the law passes, explains Anna Brown, a director at the Human Rights Law Centre and a leader of the "yes" campaign.

"There'll be no need to register your overseas marriage or take any steps – the recognition will simply follow the law coming into effect," she says.

"Regardless of whether you were married in 2007 or you're planning to get married in 2018, your marriage will be recognised."

Senator Dean Smith's same-sex marriage bill also contains a provision that means couples who married on Australian soil at foreign consulates will have their marriages automatically recognised. The British consulate, for example, offers the popular service for dual nationals, taken up by about 450 couples so far.

Senator Smith's bill passed the Senate 43 to 12 this week, and next week has been reserved for debate on same-sex marriage in the lower house. Prime Minister Malcolm Turnbull on Friday reiterated he was "very confident" it will clear the final hurdle this week. "Both houses will sit until it is done," he said.

While they are delighted other same sex couples will have the right to get married on Australian soil, legal recognition will change little for Kristy and Jo.

“We are definitely very thrilled, but we haven’t really considered ourselves to be not married,” Krsity said.

“We have just continued to refer to one and another as wife, we mark our forms as ‘wife’, and we’ve never been challenged.”