Does Signing a Birth Certificate Establish Paternity in Indiana?

No. In Indiana, signing a birth certificate does not establish paternity. For unmarried parents, legal fatherhood is created by a separate document called a Paternity Affidavit, and until that affidavit is signed, the father’s name does not go on the birth certificate at all. The birth certificate is a vital record; the Paternity Affidavit is the legal instrument that makes a man the child’s legal father.¹

The Birth Certificate Isn’t the Legal Document

This is the most common misunderstanding in Indiana family law. Parents assume that writing the father’s name on the birth certificate makes him the legal father. It doesn’t. If the parents are unmarried and no Paternity Affidavit is completed, the father is not listed on the birth certificate, and the child carries the mother’s last name.²

Once a Paternity Affidavit is properly signed, the father’s name is added to the birth record and the child may take either parent’s surname. The affidavit carries the same legal weight as a court-issued paternity decree. It creates parental rights and responsibilities without a court hearing, including the duty to pay child support and the right to seek custody or parenting time.¹

If the Mother Is Married, Different Rules Apply

The affidavit rule is for unmarried parents. If the mother is married, Indiana law automatically presumes her husband is the child’s biological father. The presumption applies to any child born during the marriage or within 300 days after it ends through death, annulment, or divorce.³ A married father does not sign a Paternity Affidavit; the law already recognizes him as the legal father.

The presumption can be rebutted, but only through a court proceeding. A biological father who believes he fathered a child born to a married woman, or a husband who believes the child is not his, can file a paternity action and request genetic testing.

How to Sign the Paternity Affidavit

For births in a hospital, the Paternity Affidavit must be completed within 72 hours after the child is born.¹ Hospital staff are required to offer unmarried parents the chance to execute the affidavit and to explain the putative father registry. A newborn coordinator typically walks parents through each section.

If you miss the 72-hour window, or the birth happened outside a hospital, the affidavit can still be completed at any local health department, any time before the child reaches the age of emancipation.⁴ There’s no late penalty, but every month without established paternity is a month the father has no legal rights and the child has no legal protections tied to him.

The form itself asks each parent for a full legal name, residential address, date of birth, and Social Security number. It also includes a written explanation of what signing means legally, which both parents should read before signing.¹ Every signature must be witnessed by a notary public or an authorized witness at the hospital or health department.⁵ Once signed, the completed form goes to the local health officer, who forwards it to the Indiana State Department of Health to update the child’s birth record.⁶

The Joint Legal Custody Checkbox

The Paternity Affidavit contains a checkbox most parents don’t know about. If both parents check the box and sign the designated lines, they agree to share legal custody, meaning both parents share decision-making authority over the child’s education, healthcare, and religious upbringing, and both get equal access to school and medical records.¹

There is a condition attached. The joint legal custody agreement is only valid if genetic test results confirming the father’s biological relationship are submitted to a local health officer within 60 days of the child’s birth. Without that confirmation, the custody agreement is void. If the parents don’t check the box, the mother has sole legal custody by default unless a court later orders otherwise.¹

Even with joint legal custody checked, the mother retains primary physical custody. Changing physical custody arrangements requires a separate court proceeding.

Changing Your Mind: The 60-Day Window

Signing a Paternity Affidavit waives the right to a trial and to genetic testing on paternity. It is not a formality. Indiana gives the father a 60-day window to change his mind, but the process is more involved than most people expect.¹

To rescind within those 60 days, the father must file an action in a court that has jurisdiction over paternity cases, and he may have to undergo and pay for genetic testing. He doesn’t need a reason, but rescission does not happen by submitting a form. It requires a court filing.²

One detail that catches people off guard: the mother cannot rescind the affidavit. Only the father has that right.²

After the 60 days close, undoing the affidavit becomes very difficult. A court will set it aside only on proof of fraud, duress, or a material mistake of fact.¹ Indiana courts enforce the deadline strictly, and genetic test results showing the man is not the biological father may not be enough to undo the affidavit once the window has closed.²

If You Can’t or Won’t Sign: Court Paternity

When parents disagree about paternity, or the father is unwilling to sign the affidavit, the alternative is a court action. Indiana law lets the mother, the alleged father, the child, or the Department of Child Services file a paternity case.⁷ Which court hears the case depends on local rules; each county designates its own.⁸

Either party can ask the court to order genetic testing, and judges are required to grant that request. Testing is usually a cheek swab from the child and the potential father, performed by a court-approved expert.⁹

A court order goes further than the affidavit in one way: the same judge can set child support, custody, and parenting time in a single proceeding. With a Paternity Affidavit alone, the mother has sole legal custody by default, and either parent must file a separate action to get a court order on support or parenting time.

What You Lose If Paternity Is Never Established

Skipping the Paternity Affidavit has consequences that outlast the birth certificate question. A child born outside of marriage cannot inherit from the father under Indiana’s intestate succession rules unless paternity has been legally established. A signed Paternity Affidavit qualifies. So does a court order of paternity, though timing rules vary with the child’s age and whether the father is still living.¹⁰ Once paternity is established, the child can inherit from the father and from the father’s entire family. Without it, those inheritance rights don’t exist on the paternal side.

Federal benefits that flow through the father also depend on established paternity. Social Security survivor and dependent benefits require the Social Security Administration to verify the parent-child relationship, and a signed affidavit or court order serves as that verification. Children whose paternity was never established can face delays or denials. The same relationship question comes up with employer health insurance coverage and dependent-based tax benefits.

There is one more risk for fathers who delay. Indiana maintains a putative father registry that protects an unmarried father’s right to receive notice of any adoption or termination of parental rights involving his child. A father who has not signed a Paternity Affidavit and has not established paternity through court should register. Failing to register waives the right to notice and gives irrevocable implied consent to adoption, which means a child can be legally adopted without the biological father ever knowing.⁶ Signing the Paternity Affidavit closes that door, because an established legal father must be notified and must consent.

1
Indiana General Assembly. Indiana Code 16-37-2-2.1 – Paternity Affidavits; Requirements; Forms; Joint Legal Custody Agreement; Penalty; Effect of Paternity Affidavit; Genetic Test; Opportunity to Consult
2
Indiana Department of Child Services. Establishing Paternity
3
Indiana General Assembly. Indiana Code 31-14-7-1 – Presumptions; Childs Biological Father
4
Indiana Department of Child Services. Paternity
5
Indiana Department of Health. Paternity Affidavit – SF 44780
6
Indiana General Assembly. Indiana Code 16-37-2-2 – Birth Certificate and Paternity Affidavit
7
Indiana General Assembly. Indiana Code 31-14-4-1 – Persons Permitted to File Action
8
Indiana Department of Child Services. Judicial Establishment of Paternity
9
Indiana General Assembly. Indiana Code 31-14-6-1 – Blood or Genetic Testing
10
Indiana General Assembly. Indiana Code 29-1-2-7 – Children Born Out of Wedlock; Inheritance