This article critically examines current practices, processes and laws regarding parentage details on birth certificates in Australia. The discussion reveals tensions between the use of birth certificates as a record of legal parentage and their use as a record of biological heritage. These tensions are exacerbated by the increasing numbers of children whose legal parents are not also their biological parents because they were conceived through assisted reproductive technologies. It is concluded that the current procedures regarding parentage details on birth certificates do not adequately support the child's right to have their legal parents named on their birth certificate. There is inadequate explanation of who is entitled to be named as a parent on the birth register. Australian policy regarding artificial conception procedures and international law emphasise a child's right to information about biological heritage. Current laws do not support the use of birth certificates as a means of providing an accurate record of biological heritage. Nor do current laws or practices support emerging family forms, where more than two people are involved in a child's conception and birth and wish to have their involvement reflected on the birth register. Reform in law and procedure is desirable, at the very least through improved explanation to new parents about who is a legal parent and who should be named as a parent on the child's birth certificate.