Illinois Paternity Laws: How is paternity established or contested?

Understanding Illinois Paternity Laws

In Illinois, as in many other states, establishing paternity is a crucial step in defining the legal relationship between a father and his child. This relationship has significant implications for child custody, support, and inheritance rights. Paternity can be established or contested through various legal means, which are governed by the Illinois Parentage Act of 2015.

Establishing Paternity in Illinois

Paternity can be established in Illinois either voluntarily or through court action. Voluntary Acknowledgement of Paternity (VAP) is the simplest method. This is a form both parents sign, typically at the hospital when the child is born, attesting to the man’s paternity. Once signed, the VAP has the force of a legal judgment and allows the father's name to be added to the birth certificate.

In cases where paternity is uncertain or disputed, either party can request a DNA test to establish biological fatherhood. If the alleged father refuses to submit to testing, a court may order him to do so. In instances where paternity is confirmed, the court will issue an order of paternity that establishes legal fatherhood.

Contesting Paternity in Illinois

If an individual wishes to contest paternity, they must file a petition with the court. There are several grounds upon which paternity can be contested: fraud, duress at signing a VAP, or mistake of fact. If successful, contesting paternity can lead to rescinding an existing VAP or challenging the presumption that a husband is the legal father of his wife's child.

It is important to note that there are strict time limits for contesting paternity. Generally, a VAP can be rescinded within 60 days of its execution unless an administrative or judicial order related to the child has been entered. Additionally, for those who wish to challenge a presumption of paternity outside of this window, they may only do so within two years after they knew or should have known of circumstances that might indicate they are not the father.

Historical Context and Examples

The evolution of paternity laws reflects changing societal norms and advancements in technology. For instance, before modern DNA testing became available, courts relied on less accurate methods and presumptions based on marital status or behavior. In one landmark Illinois case from the early 1900s, People ex rel. Hermes v. Winkel, the court held that paternity could be established based on testimony regarding exclusive access and opportunity for conception.

Today, scientific testing provides clear evidence that courts can rely on to determine paternity. Nonetheless, legal challenges still arise in complex situations such as when children are conceived through assisted reproductive technologies or when a man discovers years later that he may not be the biological father of a child he has been supporting.


Illinois law provides clear guidelines for establishing and contesting paternity but navigating these laws can still be complex. It is advisable for individuals dealing with paternity issues to consult with an attorney who specializes in family law to ensure their rights and obligations are properly addressed.