Do I Need to Establish Paternity in Texas?

 Posted on October 06, 2026 in Fathers' Rights

Paternity is the legal relationship between a father and his child. In Texas, being a child’s biological father doesn’t automatically make someone the legal father. This can create complications regarding legal matters. Lack of paternity prevents a father from getting legally sanctioned parenting time, covering his child on his insurance, or passing an inheritance on to that child.

If you’re an unmarried parent in 2026, a San Antonio, TX paternity attorney can explain why establishing paternity can benefit you and your child.

When Is Paternity Automatically Established in Texas?

Texas presumes a man is the father of a child in several situations (Texas Family Code Section 160.204). The most common is that he was married to the mother when the child was born. A presumption also applies if the child was born within 300 days after the marriage ended or the father died. It also applies if he lived in the same home as the child for the first two years and told others the child was his.

A presumed father doesn’t need to file anything to be considered the legal father.

Why Would an Unmarried Parent Need to Establish Paternity in Texas?

When parents aren’t married, paternity may need to be formally established unless the man already qualifies as a presumed father under Texas law. Under Texas Family Code Section 160.201, a paternal relationship can be established through a presumption of a man’s paternity as outlined above, a signed acknowledgment of paternity, a court order, or an adoption. The law also covers assisted reproduction.

Establishing paternity affects both parents and the child in various ways, including:

• A father can ask the court for conservatorship and possession (the Texas terms for custody and visitation).
• A mother can ask the court to order child support.
• The child may be able to inherit from the father and receive benefits through him, such as Social Security or health insurance.
• The child may gain access to the father’s family medical history.

Without legal paternity, a father may have no say in decisions about schooling or medical care. A mother may also have no way to enforce the father’s financial support of the child.

How Do You Establish Paternity in Texas?

Unmarried parents who agree on who the father is can sign a document called an Acknowledgment of Paternity. Many parents sign it at the hospital after the birth. Parents can also sign it later at a certified entity, such as a local birth registrar or a Child Support Division office. The form is filed with the Texas Vital Statistics Unit. Once filed, it generally has the same effect as a court order.

A signer can take back, or rescind, the acknowledgment before the earlier of 60 days after it becomes effective or the date of certain court proceedings involving the child. After that, a signer may challenge the acknowledgment based on fraud, duress, or a material mistake of fact. That challenge must be brought before a court order affecting the child, such as a child support order, has been issued.

If the parents don’t agree on parentage, or there’s doubt about who the father is, either parent can file a suit to establish parentage. The court can order genetic testing to prove who the father is. After that, paternity can be established as a court order. The Texas Attorney General’s Child Support Division can also help establish paternity, often as part of a child support case.

In a court case, the judge can also set conservatorship, possession, and child support at the same time, which can save parents from returning to court for each issue separately.

Is There a Deadline to Establish Paternity in Texas?

The deadline to establish paternity depends on whether the child already has a presumed father. If no man is presumed, acknowledged, or adjudicated as the father, a case can be filed at any time. This includes after the child becomes an adult.

When the child has a presumed father, a case challenging his paternity must be filed by the child’s fourth birthday. An exception can apply when the presumed father and the mother didn’t live together or have sexual relations around the time of conception. Another exception may apply when the presumed father missed the deadline because he mistakenly believed he was the biological father based on misrepresentations.

A presumed father who isn’t the biological father and misses the deadline may still have limited options under separate Texas law, depending on how and when he learned that he may not be the child’s genetic father.

Call a Bexar County, TX Paternity Attorney Today

Our firm focuses exclusively on family law, giving us experience in paternity cases. When cases are contested, our San Antonio, TX family lawyers will work toward an agreement when parents cooperate and are ready to go to court when they don’t.

Call Brandon Wong & Associates at 210-201-3832 today to schedule your first consultation.