Can a biological father claim rights if paternity is disproven?

Full question:

The man who has established paternity is not my son's biological father and he wants partial custody, once I prove that he is not his biological father. Can his biological father claim his rights?

• Category: Paternity
• Date: 04/07/2025
• State: Pennsylvania

Answer:

If a child’s parents were not married at the time of conception or birth, the child does not have a legal father until paternity is established. A name on a birth certificate does not automatically prove paternity. States typically allow parents to acknowledge paternity until the child turns eighteen through vital records offices or other designated entities.

A father can acknowledge paternity by signing a written admission or filing a civil lawsuit. Many states allow the use of an affidavit to acknowledge paternity, which must be signed by both parents, notarized, and filed with the court. Once filed, a paternity affidavit is generally irrevocable.

Courts do not automatically order paternity tests; they review the petition to determine if sufficient information exists to justify testing. If ordered, the mother, child, and alleged father will be tested at a designated facility.

Unmarried fathers have rights similar to those of married fathers. A biological father can establish paternity through a civil lawsuit, and only certain parties have legal standing to bring such an action, including the mother, the alleged father, the child, or a state agency in cases of neglect.

A court's determination of paternity is final and necessary to establish the child's rights. In Pennsylvania, paternity can be established through various means, including genetic testing, and actions must be initiated within eighteen years of the child’s birth (23 Pa.C.S.A. § 4342, § 4343).

Once paternity is established, the biological father may claim rights to custody or visitation, regardless of the previous acknowledgment by another man.