In California, a paternity action is also known as a request to establish parentage. In other words, it is a request to determine that one party is the mother and one party is the father. Under current law, it is possible to have two mothers and two fathers.
If the parents of a child are not married, one parent can file a request to establish parentage to determine parentage and establish other orders that may be necessary for the family’s well-being, including orders regarding child custody, child support, and reimbursement for childbirth expenses. Under Family Code section 7540, there is a conclusive presumption in most cases that a child of a wife who is cohabiting with a husband is a child of the marriage.
If a child’s parents were not married during the pregnancy or at the time of the birth, the child will not have a legal father until the parents formally establish parentage. If a man has lived with a child and mother and demonstrated a commitment to the child, while holding the child out to be his own, the court is entitled to presume that the man is the child’s legal father. If paternity is disputed, a party may ask the court to order a paternity test.
When two parents are not married, one parent files a Request to Establish Parentage to determine parentage and to establish other orders, including, without limitation, reimbursement for childbirth expenses, child custody, visitation, and support.
The “Parent and Child Relationship” is defined as “the legal relationship existing between a child and the child’s natural or adoptive parents incident to which the law confers or imposes rights, privileges, duties, and obligations. The terms include the mother and child relationship, and the father and child relationship [Family Code section 7601].”
Conclusive presumption as the child of marriage: Pursuant to Family Code section 7540, “…the child of a wife cohabiting with her husband, who is not impotent or sterile, is conclusively presumed to be a child of the marriage.” “Cohabiting” is defined as living together in the same dwelling and making a home together, ostensibly as husband and wife [Kusior v. Silver, (1960), 54 Cal.2d 603, 609-614].
Hypothetically, if during your marriage your wife has an affair, and she gets pregnant by the person with whom she was having an affair, under section 7540, there is a conclusive presumption that you are the child’s father. Thus, in the event that you seek to end your marriage, you could be liable for child support for a child that is technically not biologically yours.