"It’s 2021, people – we’ve got to move with the times. The UK and New Zealand have questions in their censuses, but still Australia does not."
Australians will only be asked one question on sex and given three options: male, female or non-binary.
For the first time, both the online and paper Census will allow Australians to choose the option of non-binary without having to request separate instructions and a different form, which was the case in 2016.
During a process that began in 2018, the ABS considered including new questions in the Census for the first time since 2006.
Two new topics were added to the 65-question Census form: one on long-term health conditions and another on service with the Australian Defence Force.
Courtney Act said it has been encouraging seeing the growing recognition of diverse sexual and gender identities in the last five years since the last Census in 2016, particularly with the legalisation of same-sex marriage in Australia in 2017.
Courtney Act joins push to demand LGBTIQ+ census representation
She said the lack of Census questions on sexuality and gender is "archaic" and does not reflect community support and understanding of diverse identities.
"The thing about sexuality and gender is that it is not a monolith - and it is not unique to just this little bubble.
"Queer people manifest in religious communities, in people with disabilities, people of diverse genders. There are First Nations LGBTIQ+ people. All of these facets of Australian society are contained in the LGBTIQ+ community.
"For us to have that information allows us to know who we are better as a nation and allows us to allocate resources to bring about change for more marginalised people."
The CEO of Equality Australia, Anna Brown, is preparing to fill in her Census form on Tuesday night with millions of Australians.
But there will be important data that is not captured.
"My partner won't be in the same residence as me. It means my relationship won't be visible," she told SBS News.
"It feels like a form of erasure of our community. And it is quite important information about who I am.
"Just as I tell the government how much I earn, whether I have a religious affiliation or a chronic health condition; I think I should be able to tell the government about my sexual orientation."
Only same-sex couples living in the same household will have information on their sexuality collected - excluding those who are single or not living in the same household. There will be no data recorded for transgender or intersex Australians.
Ms Brown said it is disappointing that Assistant Treasurer Michael Sukkar did not accept calls for new questions on gender and sexuality.
"At the moment, we're relying on really inadequate data on the needs of the LGBTIQ+ community. It means that when it comes to planning things like aged care, homelessness services and other community services, we don't have this full picture of the diversity of our community."
'Elevated' health risks
Nicky Bath, CEO of LGBTIQ+ Health Australia, said LGBTIQ+ youth, in particular, are missing out on resources due to the lack of data collection.
“LGBTIQ+ young people aged 16 to 27 are five times more likely to have attempted suicide than the general population. Transgender people aged 14 to 25 are a shocking 15 times more likely. There is evidence of elevated rates of drug and alcohol use, higher rates of HIV and STIs, and a significantly higher cancer burden.
“The immense challenge is we just don’t know in which parts of Australia our communities live, and a whole range of other important data to understand the contributing factors to our poorer health."
The Australian Bureau of Statistics (ABS) said they have learnt from 2016 when the survey went online for the first time, leading to a website outage due to the demand.
The federal government said it is expecting around 75 per cent of Australians will complete their forms online for this year's Census. In 2016, 63 per cent of Australians completed their Census forms online.
A petition launched by the alliance has collected 22,000 signatures.
Community groups backing the call include ACON, AFAO, Amnesty International Australia, Intersex Human Rights Australia (IHRA), Sydney Gay & Lesbian Mardi Gras, Thorne Harbour Health and Transgender Victoria.
As part of the process that began in 2018, the ABS said questions on gender and sexuality were included in the final list of eight topics that was shortlisted from the original 450.
The body then provided recommendations on the shortlist to the government, which decided on the final selection of new questions.
"We understand new data would be beneficial to collect. However, there is limited availability to add new questions to the Census," an ABS spokesperson told SBS News. "The ABS must balance the need for data with the burden—in terms of time and effort—we place on the community to fill in the Census."
In early 2023, the review process for Census topics will begin for the 2026 Census.