What Is Paternity Fraud?

 Posted on March 03, 2026 in Divorce / Family Law

Finding out that you may not be the biological father of a child you have been raising is devastating. It affects your sense of identity, your relationship with the child, and, obviously, your relationship to the mother. If this has happened to you, you’re not alone. Illinois law does give you options. Our Geneva paternity lawyer will break down paternity fraud for you and explain what steps you can take.

What Does "Paternity Fraud" Mean?

"Paternity fraud" refers to situations in which a man is falsely identified as the biological father of a child. This can happen either through a deliberate lie or a false assumption. The end result is that the man takes on legal and financial responsibility for that child, as well as the emotional responsibility of being a parent.

Paternity fraud can happen in a few different ways:

• A mother names a man as the father on a birth certificate, knowing he may not be the biological father
• A man signs a Voluntary Acknowledgment of Paternity (VAP) without knowing he might not be the biological father
• A court establishes paternity based on information that later turns out to be wrong

Once paternity is legally established, the man named as the father is typically responsible for child support until the court ends paternity, even if DNA evidence later shows he is not the biological father. That is what makes paternity fraud such a serious legal issue.

How Is Paternity Established in Illinois Law?

In Illinois, paternity can be established in several ways under the Illinois Parentage Act of 2015 (750 ILCS 46). If a couple is married when a child is born, the husband is automatically presumed to be the father. For unmarried parents, paternity is usually established by signing a specific form (VAP) at the hospital or through a court order.

These processes rely on the information available at the time. If that information is wrong, or if someone is not honest, a man can end up legally bound to a child he did not father.

What Is a Voluntary Acknowledgment of Paternity?

A Voluntary Acknowledgment of Paternity (VAP) is a legal document that both parents sign, usually at the hospital after a child is born. Signing it has serious legal consequences. Under Illinois law, a VAP must be challenged within two years of when the father knew, or should have known, that he was mistakenly or fraudulently declared the father.

After that window closes, challenging it becomes much harder. This is why acting quickly matters if there are any doubts about paternity.

Can You Challenge Paternity in Illinois After It Has Been Established?

You can challenge paternity, but it is difficult. Courts try hard to avoid action that will be bad for any children involved and will not end paternity just any time. That said, Illinois courts can reopen paternity cases under certain circumstances, including:

• Newly discovered DNA evidence that was not available before
• Proof that fraud, duress, or "a material mistake of fact" led to the original paternity finding
• Cases where the legal presumption of paternity was never properly challenged

Under 750 ILCS 46/608, a court can change a paternity judgment if the challenge is filed within the right time frame. However, courts will think about the child's established relationship with the man, the child's age, and other factors before deciding to end paternity. There is no guarantee that a DNA result alone will undo a legal paternity finding.

If you are paying child support based on a paternity order you now believe is wrong, you should speak with a family law attorney before stopping payments. Stopping payments on your own can result in serious legal consequences.

Call a Kane County Family Law Lawyer Today

Paternity fraud cases are painful and legally complex. The decisions you make early in the process can affect the outcome significantly, so it is important to get sound legal guidance as soon as possible.

If you have questions about paternity or a related family law matter in 2026, contact our Geneva family law attorney with Loire Krajniak Law, LLC at 630-448-2406 for a free consultation.