Which Court Decides Custody When Your Family Just Arrived

When a family has just moved to La Jolla, a California court generally cannot make a first custody order until California is the child's "home state." That means the child has lived here with a parent for six months in a row before the case is filed. Until then, the court in the state the family left usually decides custody.

Most people facing this question have moved recently. Some came for a new job or a university appointment. Some arrived from another state, and others came from abroad. Now the marriage or relationship is coming apart sooner than anyone expected. Often the other parent has stayed behind, or has gone back. The question is practical and pressing: can a parent file in San Diego, or does the case belong somewhere else? Is there a date on the calendar when that answer changes?

This article explains how California decides which court has the power to make custody orders, called "jurisdiction." It covers the home-state rule, the backup rules for families who have moved often, what happens when another state has already entered an order, and the narrow emergency exception. It also explains where a custody case from La Jolla is filed.

The Home-State Rule: What Family Code § 3421 Actually Says

California adopted a uniform law called the Uniform Child Custody Jurisdiction and Enforcement Act, or UCCJEA (Family Code section 3400). It is a shared set of rules that most states use. They decide which single state's courts may make and change custody orders when a family has ties to more than one place. The point is to have one court in charge, not two courts issuing orders that conflict.

The core rule sits in Family Code section 3421. Subject to the emergency exception discussed below, a California court may make an initial custody order only on one of the bases listed in section 3421(a), which work as a sequence rather than a free choice: the later bases (significant connection, all courts having jurisdiction declining in favor of California, or no other state having jurisdiction) generally apply only when an earlier basis is unavailable or has been declined. The first and primary basis applies if the following is true:

"(1) This state is the home state of the child on the date of the commencement of the proceeding, or was the home state of the child within six months before the commencement of the proceeding and the child is absent from this state but a parent or person acting as a parent continues to live in this state."

"Home state" has a precise meaning. Under Family Code section 3402(g), it is "the state in which a child lived with a parent or a person acting as a parent for at least six consecutive months immediately before the commencement of a child custody proceeding." For a baby younger than six months, it is the state where the child has lived since birth. A temporary absence counts as part of the period. "Commencement" means filing the first paper in the case (section 3402(e)).

In plain terms, the six-month clock measures where the child actually lived. It does not measure where the family meant to settle, where the child was born, or where a parent hopes the case will be heard.

Section 3421 also lists backup bases. One is "significant-connection" jurisdiction in subdivision (a)(2). The others are two residual bases in (a)(3) and (a)(4), for when other courts have stepped aside or no other state qualifies. Those come into play only in narrower situations, and they are covered below. Home-state jurisdiction is the main and preferred route. Subdivision (b) adds that these bases are the only way a California court can make a custody order. Subdivision (c) says the physical presence of a parent or child here is neither necessary nor enough on its own.

How the Six-Month Clock Works When a Family Moves

Timing is the whole question for a family that has just arrived. Because section 3402(g) looks at where the child lived, the clock runs from when the child began living in California. Paperwork such as a signed lease, a school enrollment date or a new job's start date does not start it. Those records can help prove when the child started living here. They are evidence of the date, not the date itself.

A few common patterns show how this plays out:

• The family arrived in La Jolla recently. If fewer than six consecutive months have passed, California is not yet the home state. The six-month count is measured back from the day a case is filed.
• The family left another state within the past six months. That state may still be the home state. Section 3421(a)(1) mirrors the rule in other UCCJEA states. A state can stay the home state for up to six months after the child leaves, as long as a parent still lives there. During that window, a court in the prior state may be the one with authority to decide custody.
• The child has lived here more than six consecutive months. California is then generally the home state. A new custody case would be filed in the Superior Court of California, County of San Diego.

This timing question comes up often in La Jolla. According to UC San Diego's campus profile, its main campus is in La Jolla, California. It reports 40,626 full and part-time academic, staff and medical center employees as of June 2026, and states that "UC San Diego is the largest employer headquartered in San Diego County." Many families come here for an appointment or an assignment. The U.S. Census Bureau's American Community Survey 2020-2024 5-year estimates (table B05002) report that 21.0% of residents of ZIP code 92037 are foreign-born. Families whose lives span more than one place often face exactly this question of which court comes first.

When No State Qualifies as the Home State

Some children have no home state at all. They may have moved every few months, or the family may have split time between places. For these children, section 3421(a)(2) offers a second path called significant-connection jurisdiction.

That path is open only if no other state's court has home-state jurisdiction, or if the home state's court has declined because California is the more appropriate forum. Both of the following must also be true:

• The child and the child's parents, or the child and at least one parent or person acting as a parent, have "a significant connection with this state other than mere physical presence."
• "Substantial evidence is available in this state concerning the child's care, protection, training, and personal relationships."

In practice, this analysis looks at where a child's life is actually rooted. That means where the school and medical records are, who the regular caregivers are, and where the people who know the child live. A child who has moved often, or who recently came from abroad, may have those ties spread out. The question becomes where they are most concentrated.

Two residual bases fill the remaining gaps. Under section 3421(a)(3), California may act if every court with home-state or significant-connection jurisdiction has declined because California is the more appropriate forum. Under section 3421(a)(4), California may act if no court of any other state would have jurisdiction under those criteria. These are rare, and they turn closely on the facts.

Jurisdiction Already Established in Another State: What Changes and What Does Not

Moving does not erase an existing order. Under Family Code section 3422, a court that has properly made a custody order keeps "exclusive, continuing jurisdiction" over it. Other UCCJEA states follow the same rule for their own orders. That authority lasts until one of two things happens. A court may find that the child and parents no longer have a significant connection there and that substantial evidence about the child is no longer available there. Or a court may find that the child, the parents and anyone acting as a parent no longer live in that state.

Family Code section 3423 sets the conditions for California to change another state's order. Generally, California must first have jurisdiction to make an initial order under section 3421(a)(1) or (a)(2). Then one of these must also occur:

• The other state's court decides it no longer has exclusive, continuing jurisdiction, or that California would be a more convenient forum.
• A court in California or the other state decides that the child, the child's parents and any person acting as a parent no longer live in the other state.

Enforcement works differently from modification. Under Family Code section 3445, an out-of-state custody order may be registered in California. Once registered, it is enforceable from the date of registration in the same way as a California order. A person who wants to contest the registration must request a hearing within 20 days after being served with notice. If no one contests it, the order is confirmed.

The practical effect is simple. A parent who moves to La Jolla with an existing order from another state generally cannot file a fresh case in San Diego to get a different result. The original order stays in force until jurisdiction properly shifts. Whether and when that happens depends on the facts, and no particular result is assured.

Temporary Emergency Jurisdiction: When California Can Act Immediately

Safety is the one area where the six-month rule gives way. Family Code section 3424 gives a California court temporary emergency jurisdiction if the child is present in California and one of these applies:

• The child has been abandoned.
• An emergency order is needed to protect the child because the child, a sibling or a parent is subjected to, or threatened with, mistreatment or abuse.
• The child has been unable to obtain gender-affirming health care or gender-affirming mental health care.

The word "temporary" matters. If another state already has an enforceable order, or a case has been filed in a state with proper jurisdiction, the California order must set a period of time. That period is meant to give the person seeking protection time to get an order from the other state. The California order lasts until that state acts within the period, or until the period runs out.

If there is no earlier order and no case elsewhere, the emergency order stays in effect until a court with proper jurisdiction issues one. It can become a final order only if it says so and California becomes the child's home state.

So section 3424 works as a safety valve. It is not a shortcut to permanent California jurisdiction for a family that has simply moved here.

For a parent worried about safety, the court has a dedicated process. Under Family Code section 3170(b), domestic violence cases are handled by Family Court Services under a separate written protocol approved by the Judicial Council.

Where a Custody Case Is Filed in San Diego County

Once California does have jurisdiction, the next question is which courthouse hears the case. The San Diego Superior Court assigns family cases by ZIP code. Most family law cases from La Jolla ZIP codes are filed in the Central Division, at the Superior Court of California, County of San Diego, Central Courthouse, 1100 Union Street, San Diego, CA 92101. The court publishes self-help material at sdcourt.ca.gov. The California courts' statewide self-help resources are at selfhelp.courts.ca.gov.

Mediation is part of contested custody cases. Under section 3170(a), when custody, visitation or both are contested, the court "shall set the contested issues for mediation." It is required, not optional. In San Diego County, that mediation is child custody recommending counseling with the court's Family Court Services.

Under Family Code section 3183(a), the mediator is called a child custody recommending counselor. Consistent with local court rules, that counselor may submit a recommendation to the court about custody or visitation. The recommendation must first go in writing to the parties and their attorneys before the hearing. Family Court Services, which calls this person the Family Court Counselor, says that if no agreement is reached, the Family Court Counselor makes a recommendation to the court and the court hearing proceeds. The judge makes the decision.

What to Bring to a First Conversation About Jurisdiction

Jurisdiction questions are mostly questions of dates and places. For many parents, that is a relief: the job is to gather facts, not to plan legal strategy. An attorney measures those facts against the statute. The material that usually matters most includes:

• The child's residential history. Where the child actually lived, with dates and states, for at least the six months before any case would be filed. Note any trips or stays away.
• Any existing custody orders. Orders from another state or country, with the issuing court's name and the date of the most recent order.
• The child's connections to California. School enrollment, doctors and dentists, child care, and family relationships here. These bear on the significant-connection question under section 3421(a)(2).
• Any pending case elsewhere. Under Family Code section 3429, each party must state under oath in the first filing, if reasonably ascertainable, where the child has lived during the last five years and with whom. Each party must also disclose other custody proceedings they know of. Where there are allegations of domestic violence or child abuse, certain addresses are kept confidential. If the information is missing, the court may pause the case until it is provided.

La Jolla Family Law Advocates practices California family law only. A question that turns on another state's court is one where that limit matters.

If You'd Like to Talk Through Which Court Has Your Case

Jurisdiction can turn on a few weeks either way, and on details that are easy to overlook. Those include a summer spent elsewhere, an older order nobody has looked at in years, or a filing the other parent made first. A consultation is the place to set out the child's actual residential timeline. It can also identify any order or pending case in another state and show how section 3421 applies to those dates. For a parent whose question really belongs to a court outside California, a lawyer in that state may be the more useful first call.

To talk through how the home-state rule applies to your family, contact La Jolla Family Law Advocates to request a confidential consultation.