One of the first legal same-sex weddings in Australia will happen next Thursday, after a lesbian couple in Melbourne successfully obtained a waiver from the one-month waiting period because their wedding was already paid for and family were travelling from the UK to be there.

With same-sex marriage finally enshrined in law, the first gay weddings were expected to happen from January 9 next year.

That was because all couples planning to wed — gay or straight — have to give one month's notice.

But 30-year-old Stephanie Dyball will now legally marry her 32-year-old partner Megan Stapleton next Thursday in regional Victoria.

The couple successfully applied for a waiver of the one-month waiting period because their celebrant told them if they provided the evidence to the Births Deaths and Marriages Office they may be given the right to legally marry earlier.

There are now two waivers in Victoria and one in New South Wales, and the NSW wedding could happen before the first Victorian wedding.

Ms Stapleton said the couple waited for years to be able to get legally married but decided to book the wedding months ago because they were sick of waiting for the law to change.

"We got engaged in 2012 — so quite a while ago," she said.

"We waited and waited and we got a bit tired of waiting and thought, we're not going to wait around any more for them to change the law, let's just have a wedding.

"We started planning towards the end of last year because family were coming from overseas and interstate and we wanted to give them plenty of notice."

Ms Dyball said they took evidence that they had booked everything a year ago to the Births, Deaths and Marriages Office.

"We took the evidence that my family had booked their flight from overseas back in about January-February, and we filled out all the forms and then they did say 'you know don't get your hopes up' so … to be honest our hopes weren't too high. But we were quite thrilled when they put it through," she said.

The ABC has confirmed at least two other couples have also been granted waivers — one in Victoria, one in New South Wales.

'It's still sinking in'

Megan Stapleton has been engaged to her partner Stephanie for five years. ( ABC RN: Jeremy Story Carter )

Ms Dyball and Ms Stapleton met in Beijing in 2011 and first became friends before their romantic relationship developed.

Ms Dyball is from the UK originally and the couple timed their wedding for December in order to lure their cricket-mad uncle to come during the Ashes series.

Ms Stapleton said even though they were already looking forward to their white wedding, they felt differently now that they knew the wedding would be legal.

"It's still sinking in I think," she said.

"Everything's happened so quickly. We just thought it wouldn't happen this fast even once the law was passed. We just didn't want to think about it being possible for us because we didn't want to be disappointed.

"The day was always going to be special regardless, you know it's the two of us and we're just really excited to be able to say those words that mean something in front of our family and friends."

Stephanie Dyball (pictured) met her partner Megan Stapleton in China in 2011. ( ABC RN: Teresa Tan )

Their celebrant, Jason Tuazon-McCheyne, is a same-sex marriage activist who has just had his legal Canadian marriage to his husband legally recognised.

Mr Tuazon-McCheyne said he believed it would be the first same-sex marriage in Australia because waivers were not easy to get.

He said after officiating hundreds of heterosexual weddings and 50 gay weddings that were not legally recognised, he was honoured to be the celebrant at one of Australia's first legal same-sex weddings.

"I think I've conducted over 50 weddings in the last 10 years because people don't want to wait for the law to change," he said.

"I knew that there was a provision called 'shortening of time' for the lodgement on the Notice of Intent to Marry form … sometimes they'll allow a shortening so I rang the girls and I said: 'I think you have grounds for it because you've booked your wedding in May; You've paid your deposits, you've got family coming from far away.

"It's really exciting. After having conducted over 1,000 weddings and 54 of gay couples … being a gay man myself and waking up on Saturday morning and having my Canadian marriage recognised was just amazing.

"It's really special. I feel really grateful as a gay man to be able to officiate a gay women's wedding and it's not a stunt. It's been planned for ages. It's just going to be a beautiful time and you'll have all the legitimacy and legal rights and obligations as anyone else and it's wonderful."

Jason Tuazon-McCheyne is Megan and Stephanie's celebrant. ( ABC RN: Jeremy Story Carter )

'The provision is there for anyone to apply for'

Mr McCheyne said the provision was there for anyone to apply for, but was not easy to get.

A spokesperson from the Attorney-General's Department said the circumstances for authorising a shortening of time were set out in detail in Schedule 1B of the Marriage Regulations 1963.

"This is the responsibility of 'prescribed authorities', which include court and state and territory officials, including officers in each state and territory births, deaths and marriages registry," the spokesman said.

The Attorney-General's department lists examples why a waiver of the one-month wait may be offered including that "arrangements and non-refundable payments of a considerable sum have been made for the proposed wedding, or for any celebration associated with the intended marriage, and the date for the wedding or celebration cannot be changed".

Other examples for a waiver include that "a party to the intended marriage realises that a close relative or friend of the party is in Australia but the relative or friend has a non-redeemable ticket for departure from Australia within less than a month, and the party wishes the relative or friend to be present at the wedding".

Contact details for registries are available via the Australian Government website. A full list of prescribed authorities is available on the website of the Attorney-General's department.