The Australian Family Law Act prescribes that parents of children have parental responsibility, which is defined to mean all the duties, powers, responsibilities and authorities which, by law, parents have in relation to children.

Despite the widespread reference to "parents" in the Family Law Act, there is no definition of this term. Instead, various sections describe presumptions of parentage which are situations where a person is deemed a parent in the eyes of the law.

The presumptions of parentage prescribed by the Family Law Act include the following:-

1. If a child is born to a woman while she is married, the child is presumed to be a child of the woman and her husband.

2. If a child is a born to a woman and at any time during the period between 44 weeks and than 20 weeks prior to the child's birth, and the woman lived with the man to whom she was not married, the child is presumed to be a child of the man.

3. If a person's name is entered on a register of birth or parentage information kept under the law of the commonwealth or of a state, territory or a prescribed overseas jurisdiction.

4. If a Court makes a finding that a person is a parent of a child.

5. If under the law of a commonwealth or a state, territory or prescribed overseas jurisdiction a man has signed an instrument and acknowledging that he is the father of a child and the instrument has not been annulled or set aside, then he is presumed to be the father of the child.

6. Where a child is born to a woman as a result of the carrying out of an artificial conception procedure while the woman was married to, or a de facto partner of, another person, and the woman and the other intended parent consented to the carrying out of the procedure then the child is a child of the woman, and the other intended parent.

In some cases the issue of parentage can be significant, for instance if a man is seeking parenting orders in relation to a child, or if there is an issue of child support. In such a case, evidence of parentage would be necessary. In most cases this evidence will come with the Birth Certificate of the child. Where a person is not named on the birth certificate of a child, there may not be evidence of any other the presumptions of parentage applying.

In some cases where parentage of a child is in dispute, the Court can order DNA testing to occur. This will only apply in cases where a child has been conceived by way of sexual intercourse. The results of the DNA testing will be fairly conclusive as to the parentage.

In the case of a child being conceived by way of an artificial conception procedure, there may be an issue as to whether the other party either consented to the procedure, or whether that person was in a de facto relationship with the birth mother at the time of conception.