Finding out with Family Law: Parentage Tests

Parentage tests determining the parent of the child may be needed for Family Law Lawyer matters such as child support payments, custody, access, inheritance and adoption. But with these matters, more matters arise including questions about processes and legal requirements.

Parentage Proof

The law states that a person is the presumed biological father of the child if:

  • the man was married to the child’s mother at the time she became pregnant;
  • the man is named as the father on the birth certificate;
  • the man signs a statutory declaration saying he is the father of the child;
  • the man and the mother were in a de facto relationship at the time she became pregnant; or
  • there is a court order saying the man is the father of the child.
  • These factors are considered as "proof of parentage" in applications such as child support or child maintenance.

If either the man or the woman believes the man is or is not the father of the child, even in cases in presumed proof of parentage, it is possible to have DNA testing to make sure. This report can be used to form the basis of a court order.

Parentage Tests

Also known as paternity tests, this is DNA testing to establish whether there is a family (genetic) relationship, or lack of relationship, between individuals. Samples of bodily fluids are taken (mouth swabs are increasingly replacing blood samples, though both are reported to be effective) from the mother, assumed father and the child.


Both mother and nominated biological father can agree to a parentage test, and apply to the Family Court for DNA testing to be ordered. Court forms, such as an application for a declaration of parentage and an affidavit, are required. The court can order the laboratory to provide samples for testing. Testings must be conducted by organisations accredited under the Family Law Act who will issue a report admissible in the Family Law Court. The report may assist in issues such as custody, access and child support.

A court can order a parentage test but cannot physically force someone. However refusal to take a court-ordered test can be taken into account in the court’s decision and a person can still be ‘declared’ as the father.

It is always recommended to seek legal advice prior to any court action and procedures.


It does not cost anything to apply to the Family Court for DNA testing to be ordered.

Parentage Certainty

If the nominated father’s DNA does not match the child’s DNA, he cannot be the biological father and is excluded with 100% certainty.

If the nominated father’s DNA does match the child’s DNA, he is a possible father. The Family Law Court requires the report to determine a relative chance of parentage of at least 99.5%.

Maternity for Certainty

For a DNA test to be legally admissible, the mother’s sample must be submitted.

Parentage Test Participation

The mother, child and assumed father should all be tested. If a sample cannot be obtained from the mother, the testing can still be performed though the results will be less conclusive compared to when both parents are tested. Testing with just one parent is performed only in special circumstances.

Permitting Parentage Testing

An agreement from each participant or legal guardian must be obtained in order to do the test. The Family Law Act requires consent must be obtained from the child’s mother or legal guardian if the child is less than 18 years of age. It is advisable to seek legal advice before consenting or participating in a parentage test.


The Family Law Act requires:

  • all parties involved in the testing to give their consent;
  • tests are conducted by laboratories holding an accreditation;
  • samples must be collected in a controlled environment by a medical professional;
  • a "line of custody" must be maintained for the samples; completion of Family Law Court forms and affidavit, signed by all parties and the medical professional witnessed by a Justice of the Peace on the day of sample collection;
  • mandatory photo identification for all participants; and
  • results of the test must be returned to the medical profession who will pass on to those on the affidavit.
  • Photo identification is required in the event of a dispute about the test result. The photograph may be viewed to verify the identity of the person who gave the sample. (This may be at the discretion of laboratory staff unless accompanied by a court order).
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