Establishing “paternity” in California means determining a child's legal and biological father. This can be accomplished by the parents or the family law court if necessary.
The issue of paternity sometimes becomes a significant part of California family law. It's pretty routine for people to file cases in a family court to establish paternity or challenge it to modify a child support order. Paternity disputes are often challenging.

Proving or disproving paternity, modifying a child custody agreement, establishing parental rights, and dealing with parentage matters are often complicated as specific legal requirements exist.
Fathers are legally responsible for financially supporting their children. They also have a legal right to be involved in their child's life. Custody and visitation can be determined after the court legally establishes paternity.
When parents are married when a baby is born, the family court assumes the husband is the child's father unless it's challenged within two years.
If a man who is not the husband gets a married woman pregnant, then he has the legal right to establish paternity for up to two years by requesting a paternity test.
However, when a man has a child with a married woman, there is often a high risk of never being a part of the child's life, but they could request a paternity test at any point in the child's life. Either parent can begin a case to establish parentage.
A paternity action is usually necessary when parents are not married when the child is born or when there are questions about the child's father. Our California divorce and family law lawyers will review this topic in more detail below.
What Are the Main Reasons for Establish Paternity?
The primary reasons for establishing paternity in California include the following:
- Financial support, such as child support payments,
- Legal right to child custody or visitation,
- Getting a parent's name on the birth certificate,
- Getting access to medical and healthcare records,
- Giving a father to sign documents on behalf of the child,
- Inheritance rights from either parent.
Paternity is more complicated when the child's parents are unmarried and not living together. A paternity test will need to be filed for the court to recognize a man's parentage and give court orders for support, custody, and visitation.
Despite whether a man is married to the mother of their child, there is a wide range of circumstances when they could request a paternity test as the biological father of a child has rights and responsibilities.
What Are the Steps to Establish Paternity?
If you seek to establish paternity in California when both parents agree, you must complete a “Voluntary Declaration of Paternity” form. Both parents must sign it and acknowledge they are the parents and the man is the biological father.
You can get this form at the hospital or the court. If a birth certificate was already issued, you could pay a fee to have a new one given that includes the father's name.
After the form is signed, the father will have child custody, visitation, and physical custody rights, along with legal and financial responsibilities.
Once you sign this form, you waive rights to the legal process of establishing paternity, including DNA testing, and a court determines parentage.
What About Determining Paternity Through the Courts?
Using the courts to establish paternity is often a long and complicated process. A paternity order can be submitted to the court by:
- Any man who believes they are the father of a child,
- A child's mother,
- Mother of an unborn child,
- Child support or adoption agency,
- A child over the age of 12.
A paternity order could be submitted through the child support services department, but this is not a standard procedure. Sometimes, an alleged father won't cooperate with any request to determine paternity.
The family law court will not automatically order DNA testing to establish paternity just because an action has been filed. Paternity is typically determined so that the California family court can issue orders for the following:
- Child support and visitation rights,
- Physical and legal custody of a child,
- Health and medical insurance for a child,
- Paying either parent's lawyer fees and court costs,
Suppose a mother of a child seeks to establish paternity of an alleged father who is uncooperative to avoid any responsibilities. In that case, they need to consult a family law attorney to review legal options.
Conversely, men often pursue legal representation when they believe they are a child's father, but the mother is uncooperative.
What Is the Process for Determine Parentage in California?
You'll need to contact a local family law lawyer for help since the process can be complex.
A petition will need to be filed. The “respondent” will be served with a copy and a “summons” informing the alleged father that they must respond to the petition.
If you are the filing party, you will be required to legally establish some facts related to your action, which include:
- The child's full name and date of birth,
- Relationship between each person and the child,
- If the mother was married at the time of birth,
- If married, to which person,
- Where the alleged father lives to establish jurisdiction,
- Whether there are any pending custody actions in court.
Next, the family court will order a pretrial hearing and an evaluation of the alleged issue to determine whether a trial is necessary.

Then there will be a recommendation for a trial, or the case will be dismissed.
If either parent decides not to agree with the decision, then the court could order genetic testing of all parties, including the mother, father, and child.
If either parent does not accept the final court recommendation, the case will proceed to trial, but most cases never make it this far.
Seeking a paternity case soon after a baby is born is the best method. You should contact our office for legal guidance if you need assistance with a paternity case.
A lawyer with experience handling paternity disputes can assist you in the legal process.
Furman & Zavatsky are Los Angeles divorce and family law lawyers providing legal representation across California. We offer a free case review by phone or use the contact form.