Transgender Australians can now mark X on their passports in a move by govenrment officials to avoid discrimination.

Transgender people can now choose X over M or F. Laws have previously stated that gender reassignment surgery would have to have taken place before they could officially be recognised; they would have to be 'post-op'.

This ruling also covers the 4% of the population that are of indeterminate gender, or 'intersex'.

"This amendment makes life easier and significantly reduces the administrative burden for sex and gender diverse people who want a passport that reflects their gender and physical appearance," said Foreign Minister Kevin Rudd, in a statement reported by the Associated Press.

Australian senator, Louise Pratt told a radio show "There have been very many cases of people being detained at airports by immigration in foreign countries simply because their passports don't reflect what they look like. It's very distressing, highly inconvenient and frankly sometimes dangerous."

The senator's partner was born female and now chooses to be known as a man.