Which State Has Jurisdiction Over Child Custody?

When parents live in different states, the state that decides custody is usually the child's "home state." That is the state where the child lived with a parent for at least six months in a row just before the custody case was filed. If no state meets that test, other rules apply. Once a state issues a custody order, that state generally keeps control over changes to it.

A basic question comes first: which court has the power to decide custody. This article explains how California answers that question and what the answer looks like for a family in Carlsbad or elsewhere in North County San Diego.

The Short Answer: Jurisdiction Follows the Child's Home State

California answers the "which state" question with the Uniform Child Custody Jurisdiction and Enforcement Act, usually shortened to the UCCJEA. It is a uniform law, meaning a model statute that states adopt in largely the same words so their courts follow the same rules. According to Cornell Law School's Legal Information Institute, the UCCJEA was adopted by every state except Massachusetts as of June 2024, and it is designed to prevent jurisdictional forum shopping based on favorable child custody awards. California's version appears in Family Code sections 3400 through 3465. Section 3400 states that this part "may be cited as the Uniform Child Custody Jurisdiction and Enforcement Act."

Jurisdiction here means a court's legal power to make a custody order at all. It is a separate question from what that order should say. A California judge deciding custody looks at the child's best interests. Under Family Code sections 3011 and 3020, the child's health, safety and welfare come first. A judge reaches those factors only after the jurisdiction question has been settled. The broader child custody process assumes the court already has authority to act.

The act reaches more than divorce. Family Code section 3402(d) defines a "child custody proceeding" as a proceeding in which legal custody, physical custody, or visitation is an issue, and says the term includes a proceeding for dissolution of marriage, legal separation of the parties, neglect, abuse, dependency, guardianship, paternity, termination of parental rights, and protection from domestic violence, in which the issue may appear. Section 3402(c) provides that a "child custody determination" does not include "an order relating to child support or other monetary obligation of an individual."

For a family living in Carlsbad, a custody case that belongs in California is generally heard at the Superior Court of California, County of San Diego, North County Regional Center, 325 South Melrose Drive, Vista, CA 92081.

What the UCCJEA's Home-State Rule Actually Says

Family Code section 3402(g) supplies the definition the whole system rests on. It reads:

"'Home state' means 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. In the case of a child less than six months of age, the term means the state in which the child lived from birth with any of the persons mentioned. A period of temporary absence of any of the mentioned persons is part of the period."

Each part of that definition does real work.

"Commencement" is defined in section 3402(e) as "the filing of the first pleading in a proceeding." The six months is counted backward from the day the first paper is filed. The date of the move or the date of the separation does not set the count.

"Six consecutive months" means six months in a row in the same state.

"Temporary absence" is not defined in section 3402. Under section 3402(g), "a period of temporary absence of any of the mentioned persons is part of the period." Whether a particular absence was temporary or was really a move depends on the facts.

"Person acting as a parent" is defined in section 3402(m). It covers a person other than a parent who has physical custody of the child, or has had physical custody for six consecutive months, including any temporary absence, within one year immediately before the case was filed, and who has been awarded legal custody by a court or claims a right to legal custody under California law.

Family Code section 3421(a)(1) then turns the definition into a rule of power. A California court generally has jurisdiction to make an initial custody determination if California "is the home state of the child on the date of the commencement of the proceeding." It also has jurisdiction if California "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."

Under that second clause, California can still have jurisdiction for up to six months after it stopped being the child's home state, if the child is absent from California and a parent or person acting as a parent continues to live here.

An initial determination, under section 3402(h), is "the first child custody determination concerning a particular child." Changing an existing order is a different question, covered further below.

When No State Qualifies as the Home State — Significant-Connection Jurisdiction

Some children have no home state. A family may have moved twice in a year, or a child may have split time between states with no six-month stretch anywhere. For those situations, Family Code section 3421(a)(2) provides a fallback. A California court may act if no other state has home-state jurisdiction, or if the home state's court has declined to act because California is the more appropriate forum, and both of these are true:

• "The child and the child's parents, or the child and at least one parent or a 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 plain words, significant connection means real ties to California beyond simply being here. Substantial evidence, under the second requirement, is evidence available in California concerning the child's care, protection, training, and personal relationships.

Two narrower bases sit behind that one. Under section 3421(a)(3), California may act when every court with home-state or significant-connection jurisdiction has declined, on the ground that California is the more appropriate forum. Under section 3421(a)(4), California may act when no court of any other state would have jurisdiction under the first three tests.

The order matters. Significant connection is a fallback. It applies only when the home-state test does not settle the question. Section 3421(b) makes these four paths "the exclusive jurisdictional basis" for a California custody determination. Section 3421(c) adds: "Physical presence of, or personal jurisdiction over, a party or a child is not necessary or sufficient to make a child custody determination." A child being in California on the day of filing generally does not settle the question either way.

How California Courts Handle Competing Claims from Another State

Family Code section 3426(a) generally bars a California court from going forward when a custody case was already started in another state that has jurisdiction "substantially in conformity" with the act. The exception is when that court has ended or paused its case because California is the more convenient forum.

Section 3426(b) sets out what the court does. Before hearing a custody case, the California court "shall examine the court documents and other information supplied by the parties." If it finds a qualifying case already pending elsewhere, it "shall stay its proceeding and communicate with the court of the other state." If that other court does not decide California is the more appropriate forum, the California court "shall dismiss the proceeding."

Family Code section 3410 allows a California court to "communicate with a court in another state." The parties may be allowed to take part. If they cannot, they "must be given the opportunity to present facts and legal arguments before a decision on jurisdiction is made." Apart from routine matters like calendars, "a record must be made of the communication." The parties must also be told promptly and given access to that record.

Family Code section 3427(a) lets a California court that has jurisdiction "decline to exercise its jurisdiction at any time if it determines that it is an inconvenient forum under the circumstances and that a court of another state is a more appropriate forum." The issue "may be raised upon motion of a party, the court's own motion, or request of another court." Before deciding, the court allows the parties to submit information and considers all relevant factors, including whether domestic violence has occurred and is likely to continue and which state is positioned to protect the parties and the child more effectively, how long the child has lived outside California, the distance between the courts, the financial hardship to the parties, any agreement of the parties on which state should assume jurisdiction, the nature and location of the evidence, the ability of each state's court to decide the issue expeditiously, and each court's familiarity with the facts and issues. If the court finds it is an inconvenient forum and another state's court is more appropriate, section 3427(c) says it "shall stay the proceedings upon condition that a child custody proceeding be promptly commenced in another designated state."

Family Code section 3428 deals with a parent who tries to create jurisdiction through what it calls "unjustifiable conduct." If a California court has jurisdiction only because of that kind of conduct, it "shall decline to exercise its jurisdiction" with limited exceptions. One exception is that the parents and all persons acting as parents have acquiesced in the exercise of jurisdiction. Another is that the proper state's court found California more appropriate. A third is that no other state would have jurisdiction. If a court dismisses or stays a case on that ground, 3428(c) says it "shall assess against the party seeking to invoke its jurisdiction necessary and reasonable expenses" including attorney's fees and travel expenses, unless that party establishes the assessment would be clearly inappropriate. Section 3428(d) says a court shall not count against the petitioner a taking or keeping of the child if there is evidence it resulted from domestic violence against the petitioner. Separately, Family Code section 6323(a)(1) provides that, in the domestic violence restraining order process, the court may issue an ex parte order determining the temporary custody and visitation of a minor child, on the conditions the court determines, to a party who has established a parent and child relationship. For more on that process, see the page on domestic violence and restraining orders.

Changing an Existing Custody Order

Under section 3402(k), a modification is any custody determination that "changes, replaces, supersedes, or is otherwise made after a previous determination concerning the same child." Section 3422 governs which court may modify a custody determination.

Family Code section 3422 describes the rule from California's side. A California court that properly made a custody determination "has exclusive, continuing jurisdiction over the determination." Exclusive, continuing jurisdiction means that court alone keeps the power to change its order. That lasts until one of two things happens:

1. A California court decides that neither the child, nor the child and one parent, nor the child and a person acting as a parent have a significant connection with California, and that substantial evidence about the child is no longer available here.
2. A California court, or a court of another state, decides that the child, the child's parents and any person acting as a parent "do not presently reside in this state."

Under section 3422(b), a California court that has lost exclusive, continuing jurisdiction may modify its own earlier order only if it could make an initial determination under section 3421.

Enforcing a Custody Order Across State Lines

Enforcement means making the existing order work. That is separate from changing it. Family Code section 3443(a) provides that a California court "shall recognize and enforce a child custody determination of a court of another state" if that court exercised jurisdiction "in substantial conformity" with the act, or the determination was made under factual circumstances meeting the act's jurisdictional standards, and the determination has not been modified in accordance with it. Section 3443(b) adds that a California court "may utilize any remedy available under other laws of this state" to enforce it.

California law also provides a process for registering another state's custody order. Under Family Code section 3445(a), a child custody determination issued by a court of another state "may be registered in this state, with or without a simultaneous request for enforcement," by sending the appropriate California court a letter or other document requesting registration, two copies of the determination (one certified) with a statement under penalty of perjury, based on the knowledge and belief of the person seeking registration, that the order has not been modified, and, except as section 3429 provides, the name and address of the person seeking registration and of any parent or person acting as a parent who has been awarded custody or visitation. The court files the determination as a foreign judgment and serves notice on those persons. A registered determination is enforceable as of the date of registration in the same manner as a determination issued by a California court, and a person who wants to contest the registration must request a hearing within 20 days after service of the notice.

The constitutional backdrop is the Full Faith and Credit Clause, Article IV, Section 1 of the U.S. Constitution, which directs that "Full Faith and Credit shall be given in each State to the public Acts, Records, and judicial Proceedings of every other State."

Under section 3443(a), the questions are whether the other court exercised jurisdiction in substantial conformity with the act or under factual circumstances meeting its standards, and whether the determination has been modified.

What This Means for Families in Carlsbad and North County San Diego

The analysis begins with the child's calendar. If a child has lived in Carlsbad, in a neighborhood like Carlsbad Village, or elsewhere in North County, including Oceanside, Vista, San Marcos, Encinitas, Solana Beach, Del Mar or Rancho Santa Fe, for at least six consecutive months with a parent before a case is filed, California is likely the home state. The case would then belong in the San Diego Superior Court, generally at the North County Regional Center in Vista.

Recent moves make the answer less clear. These include a child who arrived in Carlsbad three months ago, a child who left a month ago, or a case where the other parent lives in another state. In those situations the section 3421 analysis decides which court has authority, and the answer depends on dates and facts. Whether an absence was temporary, whether a case is already pending elsewhere, and whether an earlier order exists can each change the result. For related topics, see the divorce process and custody schedules.

Carlsbad Family Law Advocates practices California family law only.

Talking With the Firm About Custody Jurisdiction

Custody jurisdiction usually comes down to dates. The questions include when the child moved, where the child stayed, whether a trip was temporary, and whether another state's court has already acted. A consultation is a place to raise those questions. To talk with the firm about custody jurisdiction, call Carlsbad Family Law Advocates at (760) 840-5102 for a confidential consultation.