Parentage sounds like a question with an obvious answer until you look at how many families it does not fit. Donor conception, co-parenting arrangements between friends, same-sex couples, and step-parents who have done the raising for a decade.

The Family Law Act uses the word parent without exhaustively defining it. In 2019 the High Court had to decide what it means.

What the case does and does not settle

It does not decide that donors generally are parents. The Court said in terms that it was unnecessary to decide whether a man who does no more than provide semen for an artificial conception procedure is a parent, and it did not decide it. That question is still open.

What Masson turned on was the whole factual relationship: the understanding at conception, the birth certificate, and years of actual parenting. It also held that the New South Wales presumption that a biological father in that situation is not the father did not apply in the federal jurisdiction, because Part VII of the Family Law Act already provides comprehensively for who is a parent.

It also does not mean the label decides the outcome. Being a parent gives you standing and changes the frame, but the orders a court makes still come down to the child's best interests.

If you are planning this now

  • Write down what everyone intends, before conception. A written agreement is not binding on a court about a child, but it is powerful evidence of what was understood.
  • Be deliberate about the birth certificate. It carried real weight in Masson.
  • Understand that conduct after the birth matters as much as the plan. Involvement builds the case; absence undoes it.
  • Get advice in your state as well. Victoria has its own parentage presumptions in the Status of Children Act 1974, and they do not always line up with the federal position.

The practical message from Masson is that courts look at the family that actually exists rather than the one that fits the form. If you are building something outside the standard shape, put the intentions in writing at the start. It costs an hour of advice then and a great deal later.