For unmarried parents in Brownsville and across the Rio Grande Valley, a child's legal father is not always the man listed in family conversations. Texas law sets out specific ways a father-child relationship is legally established, and those rules affect a child's birth certificate, child support, conservatorship, and possession. The main statute is the Uniform Parentage Act in Chapter 160 of the Texas Family Code. This article summarizes what the statute and the Office of the Attorney General (OAG) say about presumed fathers, the Acknowledgment of Paternity (AOP), rescission and challenges, and court proceedings to adjudicate parentage. Sources were checked on October 23, 2026. It does not predict the outcome of any case.

How a father-child relationship is established

Section 160.201(b) lists the ways the father-child relationship is established:

  • an unrebutted presumption of paternity under Section 160.204;
  • an effective acknowledgment of paternity, unless it has been rescinded or successfully challenged;
  • an adjudication of paternity by a court;
  • adoption; or
  • consent to assisted reproduction by the man's wife, under Subchapter H, that resulted in the child's birth.

The OAG's paternity page puts it plainly: for unmarried parents, the biological father does not have legal rights to his child until paternity is established.

Presumed fathers

Under Section 160.204, a man is presumed to be the father in several situations, including when:

  • he is married to the mother and the child is born during the marriage;
  • the child is born before the 301st day after the marriage ends by death, annulment, declaration of invalidity, or divorce; or
  • during the first two years of the child's life, he continuously lived in the household with the child and represented to others that the child was his.

A presumption can be rebutted only by a court adjudication or by a valid denial of paternity filed together with another man's valid acknowledgment of paternity.

The Acknowledgment of Paternity (AOP)

Section 160.301 allows the mother and a man claiming to be the biological father to sign an acknowledgment of paternity with the intent to establish his paternity.

What the AOP must contain

Section 160.302 requires the acknowledgment to be in a record, signed or otherwise authenticated under penalty of perjury by both the mother and the man, and to state:

  • that the child has no presumed father, or has a presumed father whose full name is stated;
  • that the child has no other acknowledged or adjudicated father;
  • whether genetic testing has occurred and, if so, that the results are consistent with the man's claim; and
  • that the signers understand the acknowledgment is the equivalent of a judicial adjudication of paternity and that a challenge is permitted only in limited circumstances.

An acknowledgment is void if it names another man as presumed father without a filed denial from him, names another acknowledged or adjudicated father, or falsely denies that one exists.

How it is completed in practice

According to the OAG's Acknowledgment of Paternity page, both parents must work with an AOP-certified entity trained by the OAG. The OAG's materials list the OAG Child Support Division, the local registrar (county clerk's office), and local vital statistics offices as places where an AOP can be completed. The AOP Hotline is (866) 255-2006. The OAG also notes that minors can sign the AOP without parental consent, and Section 160.304 says an acknowledgment signed by a minor is valid if it otherwise complies with the chapter.

Timing and effect

Section 160.304 allows an AOP to be signed before the child's birth and says it takes effect on the date of birth or the date it is filed with the vital statistics unit, whichever is later. Section 160.305 says a valid, filed acknowledgment is the equivalent of an adjudication of paternity and confers all the rights and duties of a parent. The OAG's AOP information sheet notes that either parent may seek primary custody and that signing may lead to an order to pay child support and medical support. Section 160.306 prohibits the state from charging a fee to file an acknowledgment, denial, or rescission.

When the mother is or was married to someone else

If the mother is married to a man who is not the biological father, or the child is born within the presumption period after a divorce, the OAG explains that the Denial of Paternity section must be completed by the mother and her spouse, the presumed father. Under Section 160.303 and Section 160.304(a), when both an acknowledgment and a denial are needed, neither is valid until both are filed.

Changing your mind: rescission and challenges

  • Rescission. Under Section 160.307, a signer may rescind before the earlier of the 60th day after the acknowledgment takes effect or the date a court proceeding relating to the child, including one to establish child support, is started. The OAG identifies the rescission form as VS-158.
  • Challenge after that period. Under Section 160.308, a signer may challenge only on the basis of fraud, duress, or material mistake of fact, and only before an order affecting the child is issued. The person challenging has the burden of proof. Genetic testing that does not identify the man as the father under Section 160.505 counts as a material mistake of fact.

Adjudicating paternity in court

When parents do not sign an AOP, or paternity is disputed, a court can decide it. Section 160.602 lists who may bring the case, including the child, the mother, a man whose paternity is to be adjudicated, and the support enforcement agency. Section 160.502 requires the court to order genetic testing when a party requests it.

Time limits depend on the child's situation:

  • No presumed, acknowledged, or adjudicated father: a case may be brought at any time (Section 160.606).
  • Child with a presumed father: generally by the child's fourth birthday, with exceptions in Section 160.607.
  • Child with an acknowledged or adjudicated father: a non-signer generally must file by the fourth anniversary of the acknowledgment or adjudication (Section 160.609).

Under Section 160.636, an order adjudicating parentage must identify the child, may order an amended birth record, and may include retroactive child support under the Chapter 154 guidelines. Our article on Texas child support guidelines explains those guidelines, and our article on the standard possession order covers possession schedules.

Step by step: a practical overview

Step 1: Identify whether there is a presumed father

Check whether the mother was married at the birth or within the 300-day window before it.

Step 2: Read the AOP materials before signing

The OAG calls the AOP a legal document, and its information sheet says a man who is not sure he is the biological father should not sign and may want a genetic test.

Step 3: Find a certified entity

Call the AOP Hotline or ask a local child support office or county clerk.

Step 4: Keep copies and note the 60-day window

Rescission deadlines are short and run from the effective date.

Step 5: Talk with a lawyer about disputed or complicated situations

This is especially important if another man may be a presumed father, or if a court case is already pending.

Frequently asked questions

Does signing the AOP set child support or a visitation schedule?

No. It establishes legal paternity. Support, conservatorship, and possession are set by agreement or court order.

Can the AOP be signed after the baby comes home from the hospital?

Yes. The OAG's AOP information sheet says it may be completed before birth, at birth, or at any time after birth prior to any court hearing in a proceeding involving the child.

Does a parent living in Mexico have to come to Texas to sign?

The OAG says special steps are available when parents cannot complete the AOP at the same time or place; ask the AOP Hotline or a certified entity.

Questions in Brownsville and South Texas

Families in Brownsville and the Rio Grande Valley often want to understand paternity before signing documents or going to court. CRG Law's Brownsville office works with clients on family law matters that include parentage, child support, and conservatorship. Contact the office with questions about these basics.