A battle to include sexual orientation and gender questions in the next census will go to the Human Rights Commission.
Newcastle parent April Long says they felt excluded when answering the 2021 survey with their partner Kelly given there was no question about sexual orientation.
The 65-question census also asked a difficult question about the rainbow family's baby Kaison.
"Kaison has two mums - I'm Mumma and Kelly is Mummy - but the form asked where Kaison's mother and father were born," Long said on Friday.
"Our initial reaction was shock. We were unable to complete it accurately. It didn't capture us. It made us feel invisible and it didn't count us."
Long, a chief executive for a non-profit addiction program provider, said they filed a complaint on Thursday with the Australian Human Rights Commission (AHRC) alleging the failure to properly count LGBTIQ+ people in the census amounted to unlawful discrimination.
Equality Australia, which joined as a co-complainant, said Long's experience was replicated thousands of times with other LGBTIQ+ people and their families on census night.
"The fact is we still don't know how many LGBTIQ+ families there are in Australia, nor where they are located," Equality Australia legal director Ghassan Kassisieh said in a statement.
The complaint alleges the Australian Bureau of Statistics (ABS) and the assistant treasurer - who was then Liberal MP Michael Sukkar - engaged in deliberate conduct that meant the statistics bureau "could not follow its own guidance" on the collection of data on sexual orientation, gender identity and sex characteristics.
Current assistant treasurer Stephen Jones has been contacted for comment.
The ABS said it was committed to ensuring everyone could participate in the census and help deliver high-quality data for communities, and noted the government of the day determined census topics.
It was "disappointed" to hear of Long's concern and would work with them and Equality Australia.
"The ABS will provide full support to the AHRC in relation to any complaint and seek a resolution with concerned parties," the bureau said in a statement.
The bureau will consult with LGBTIQ+ communities and other stakeholders to understand data needs and potential topics and test any proposed changes for the 2026 census.
