Why Is Establishing Paternity Important in Illinois?

 Posted on September 02, 2026 in Family Law

When a child is born to a married couple, both spouses are presumed to be the child's legal parents. However, when a child is born to an unmarried mother, or when the identity of the child's father may be in doubt, it might be necessary to establish the child's legal parentage. Establishing paternity is important for the child, but it also benefits the father and mother, too. For example, legal paternity can be required before a court decides parenting time, parental responsibilities, and child support.  

If you need to address issues related to your child's parentage, speaking with an experienced Lombard, IL family law attorney can guide you through your next steps and help you establish paternity. With over 100 years of combined experience, our lawyers at A. Traub & Associates can be trusted to handle sensitive parentage matters.

When Is Paternity Presumed?

In Illinois, paternity is automatically presumed in certain situations. If a child is born to parents who are married to each other, the law presumes that the husband is the legal father. This is true even if the couple later separates or divorces soon after the birth. The presumption can also apply if the child is born within 300 days after a marriage or civil union ends, after a legal separation, or even death.

Unmarried parents do not receive this automatic presumption. An unmarried father, for example, could be caught off guard to learn that he must establish legal parentage before seeking parenting time or parental responsibilities. For these reasons, unmarried parents should establish paternity as early as possible, ideally soon after the child is born.

How Is Paternity Established in Illinois?

Paternity is the legal establishment of the identity of a child’s father. Simply having a person’s name on a birth certificate does not necessarily indicate paternity. In fact, paternity can be established in a variety of ways, including:

• When both parents sign a Voluntary Acknowledgement of Parentage (VAP) form
• After an Administrative Parentage Order is entered by the Illinois Department of Healthcare and Family Services
• After a court order of paternity is issued by a judge 

At A. Traub & Associates, we represent fathers and mothers in paternity cases. We can help you identify the right path to establish legal parentage, keeping the best interests of your family at heart.

Should You Sign a VAP?

A VAP is a legal document that both parents can sign to establish paternity outside of court. Hospitals often offer this form shortly after birth. Parents can also sign it later at a local registrar of vital records or county clerk’s office.

Some parents hesitate before signing. A father may want to confirm the child is biologically his before putting his name on a legal document. A mother may worry about naming the wrong person or about how paternity will affect future custody decisions. These concerns are understandable, since signing a VAP carries real legal weight.

 Illinois law gives parents a short time to change their minds after signing a VAP. Either parent can cancel it within 60 days, or before a court case involving the child and that parent begins, whichever comes first (750 ILCS 46/307). After that, canceling a VAP becomes much harder.

Once the initial rescission period expires, a parent has up to two years from the date the VAP becomes effective to challenge it. Within that period, a parent would need to prove fraud, duress, or a material mistake of fact to invalidate the VAP.

What Is the Legal Significance of Paternity in 2026?

Establishing paternity affects the child, the mother, and the father. The child may feel a sense of identity and belonging simply by knowing who his or her father is. Mothers benefit because paternity determinations help to secure support from the father. Establishing paternity benefits the father, too. A man who is legally recognized as a child’s father is:

• Responsible for providing financial support for the child
• Can give the child access to benefits such as Social Security and health insurance
• Entitled to seek parenting time and decision-making responsibility over the child

Establishing paternity does not automatically give a father parenting time or decision-making responsibilities. Those issues are decided based on the child’s best interests. What a paternity order does is give the father the right to request parental responsibilities. In addition to the reasons above, legal paternity can help protect a child’s inheritance rights if the father dies. Similarly, a child benefits from having access to a family history of medical records.  

What Happens at a Paternity Hearing?

When parents cannot agree, or when a VAP is not signed, paternity can be established through a court hearing. Either parent, or in some cases the state, can file a petition asking the court to determine paternity.

During paternity proceedings, the court often orders genetic testing. A simple cheek swab can confirm biological parentage with a high degree of accuracy. Both parents and the child may be asked to complete this test.

If genetic testing supports paternity, the results can be used to establish the father as the child’s legal parent. Once parentage is established, the court can address related matters such as child support, parenting time, and parental responsibilities.

Contact a DuPage County, IL Parentage Lawyer

Even if a couple was never married, they still have important decisions to make if they separate and have a child together. Before the court can address parenting time or child support, paternity often needs to be established. If you are a father who is not yet legally recognized as your child’s parent, or a mother who needs to establish paternity, a parentage lawyer can help you understand what to do next.

At A. Traub & Associates, we understand the emotional effects on mothers, fathers, and children when addressing family law issues, and we work hard to ensure that children's best interests are protected. To schedule a confidential consultation, call our Lombard, IL family law attorneys today at 630-426-0196.