Gender and relationship recognition
The Marriage Act 1961 (Cth) defines marriage as “the union of a man and a woman to the exclusion of all others”. Previously, Australian courts adopted the UK attitude that gender is determined at birth and cannot be altered (see Corbett v Corbett  2 All ER 33). However, the Corbett ruling was overturned in Australia in the appeal case of Re Kevin  FamCA 94, where the court found that transsexual individuals are legally allowed to marry according to their new gender.
However, a consequence of the Re Kevin decision is that courts determine gender (for the purpose of marriage law) at the date of marriage. Also, a person must be unmarried to change the sex on their birth certificate. This means that transgender individuals who enter into a heterosexual marriage and later transition into the opposite gender are not allowed to amend their birth certificate to reflect their new gender. To amend their birth certificate, they must divorce their partner. However, they will not be able to remarry their spouse because same-sex marriage is not legal in Australia.
A Bill was introduced in the Victorian Parliament in 2016 to remove the requirement that a person be unmarried in order to alter their sex on their birth certificate. The Bill was rejected on 7 December 2016.
“Gender dysphoria” is a condition where a person’s sense of their own gender contradicts their biological sex. Hormonal treatment for gender dysphoria in young people involves two steps:
1 Stage one treatment: puberty blocking medication (fully reversible);
2 Stage two treatment: cross-sex hormone treatment (partly irreversible).
In Australia, at the time of writing (30 June 2017), court approval is not needed to access stage one treatment; parental consent is sufficient (see Re Jamie  FamCAFC 110).
However, accessing stage two treatment is less straightforward. The courts classify stage two treatment as a form of special medical procedure that can only be performed on children with court approval. There are two avenues that can be followed to access stage two treatment:
1 In Re Jamie, the court decided that stage two treatment is a non-therapeutic treatment (and therefore is beyond the scope of parental consent). This follows the High Court precedent of the case of Re Marion (Secretary, Department of Health and Community Services) v JWB & SMB (1992) 175 CLR 218, where the court decided that non-therapeutic treatment (e.g. sterilization) requires a court order, and falls outside the ordinary scope of parental power to consent to medical treatment.
So parents may seek a court order that authorises their child to be given stage two treatment. In doing so, the court must be persuaded that the treatment is in the child’s best interest. Generally, a court order authorising stage two treatment is only given after the court has heard expert medical and psychological advice (see Re Shane  FamCA 864).
2 The child and their family may seek a court order declaring that the child is “Gilick competent”. A court will deem a child to be Gilick competent if it believes that the child is sufficiently intelligent and mature to fully understand what is involved in stage two treatment. If a court decides that a child is Gilick competent, the child has authority to authorise stage two gender dysphoria treatment, as was the case in Re Spencer  FamCA 310.