Paternity in California -- Unmarried Father Rights and Child Support

Why Legal Paternity Matters in California

In California, a child born to married parents is presumed to be the child of both spouses -- no separate legal action is needed to establish paternity within a marriage. For children of unmarried parents, legal paternity must be established before either parent can obtain court orders for custody, visitation, or child support. Without established paternity, an unmarried father has no legal right to custody or visitation -- even if he has been actively involved in the child's life for years. Without established paternity, the child has no legal right to child support from the father, inheritance rights, access to the father's employment-based health insurance, Social Security survivor benefits, or other rights that come with the legal parent-child relationship.

Establishing paternity is in the interest of both parents and the child: the mother gains the legal framework to seek child support and the father gains legal rights to custody and parenting time. The child gains financial support, access to benefits, and a legal connection to both parents' families and heritage.

How to Establish Paternity in California

California law provides two primary paths for establishing paternity outside of marriage. The first is a Voluntary Declaration of Parentage (VDOP) -- a form signed by both parents at the hospital at the time of birth, or at any subsequent time, in which both parents declare that the signing father is the biological father of the child. A VDOP has the same legal effect as a court judgment of paternity once it is completed and filed with the California Department of Child Support Services (DCSS). No court proceeding is required. The VDOP allows the father's name to be placed on the birth certificate.

The second path is a court action for paternity. Either the mother, the alleged father, the child (through a guardian), or the DCSS can file a Petition to Establish Parental Relationship in the Superior Court. Once filed, the court can order genetic testing (DNA testing) to determine biological parentage. The test results are typically admissible and, if the testing shows a 99% or higher probability of paternity, create a presumption that the tested individual is the biological father. After genetic testing confirms paternity, the court enters a Judgment of Paternity that has the same legal effect as a VDOP.

Unmarried Father Rights in California

What rights does an unmarried father have in California once paternity is established? An unmarried father who has legally established paternity has the same parental rights as a married father: the right to petition for joint or sole physical custody; the right to petition for joint or sole legal custody (shared decision-making); the right to court-ordered parenting time (visitation) if custody is primarily with the mother; the right to be informed of and participate in the child's education and healthcare; and the right to object to the child's relocation out of state.

Unmarried father rights before paternity is established are more limited. A biological father who has not yet established legal paternity has no automatic right to prevent the mother from making parenting decisions, relocating with the child, or placing the child for adoption. Establishing paternity as early as possible -- ideally at the child's birth through a VDOP -- gives the father immediate legal standing to seek custody and parenting time orders from the court. An unmarried father who delays establishing paternity risks the child developing a primary attachment to the mother's household that the court will then be reluctant to disrupt.

How Paternity Affects Child Support

How paternity affects child support in California: child support cannot be ordered until parentage is legally established. Once paternity is established -- either through a VDOP or a court judgment -- the court applies the California guideline child support formula to calculate the appropriate monthly support amount. The formula uses each parent's net disposable income (gross income less mandatory payroll deductions, income taxes, and health insurance) and the percentage of time each parent has physical custody of the child. The parent with more income and less custody typically pays support; the parent with less income and more custody typically receives support.

Child support is mandatory once paternity is established -- it is not optional. A court can order past-due support (arrearages) going back to the date of the child's birth in some circumstances, particularly where the father was aware of the pregnancy and avoided establishing paternity. Genetic testing and paternity establishment can be initiated by the DCSS on behalf of the mother or the child even without a court proceeding, through an administrative paternity establishment process that is separate from the family law court.

Challenging a Voluntary Declaration of Parentage

A VDOP is treated like a court judgment and is not easily set aside. A VDOP can be challenged within two years of signing if the challenging party was not provided the required disclosures about the legal consequences of signing, signed under fraud or duress, or was not the biological father and did not know the child was not his biological child at the time of signing. After the two-year window has passed, a VDOP can only be set aside on very limited grounds and typically requires proving that setting it aside serves the child's best interests in addition to proving the procedural ground.

The two-year challenge window and the difficulty of setting aside a VDOP after it expires means that a man who believes he may not be the biological father of a child should seek legal advice immediately before signing a VDOP, rather than signing and attempting to challenge it later. Once signed, the legal presumption of paternity is powerful and difficult to overcome.

Paternity Attorney in Orange County and Riverside County

Paternity matters -- whether establishing paternity to obtain custody rights, defending against a paternity claim, or challenging an existing VDOP -- require experienced family law representation. The legal and financial consequences of paternity establishment are permanent and far-reaching. Furubotten Law, APC represents both parents in paternity proceedings and related custody and child support matters throughout Orange County and Riverside County. Call (714) 795-3862 for a complimentary initial case evaluation.

Last reviewed: June 2026 · Author: Denise Furubotten, Esq.

Additional Paternity Questions

Court ordered DNA test in California: either parent can request a court-ordered genetic test in a paternity proceeding. The court has authority to order genetic testing of the child, the alleged father, and the mother. Testing is typically performed through a certified laboratory using a buccal swab. Results showing 99% or higher probability of paternity create a statutory presumption of paternity under California Family Code section 7555. The test is non-invasive and highly accurate. A party who refuses a court-ordered DNA test can face evidentiary sanctions.

Parental rights vs custodial rights in California: parental rights is the broader concept -- the legal relationship between a parent and child, including the right to make decisions about the child's upbringing and the obligation to provide financial support. Custodial rights refers specifically to physical and legal custody -- where the child lives and who makes day-to-day and major decisions. A parent can have parental rights (and the obligation to pay child support) without having physical custody. Termination of parental rights ends both the rights and obligations of the legal parent-child relationship.

Petition for paternity in California: the formal court filing to establish parentage is called a Petition to Establish Parental Relationship. It is filed in the Superior Court family law division. Either the mother, the alleged father, the child's guardian, or the Department of Child Support Services can file the petition. After filing and service, the court orders genetic testing if paternity is disputed, and enters a judgment of paternity based on the test results or on the parties' stipulation.