Opinion

We hold in this case that in a proceeding under the Family Code the superior court lacked in personam jurisdiction and subject matter jurisdiction to enforce provisions of the parties’ marital settlement agreement (MSA) requiring an adult disabled child living in Thailand to visit his father in California. We further hold the court lacked subject matter jurisdiction to enforce provisions of the MSA requiring the mother to encourage and implement visitation and give the father written updates on their son’s activities. The effect of those provisions is to control the son’s conduct, and the mother has no legal authority over him because he has reached 18 years of age. Accordingly, the mother may not be subject to the court’s contempt powers for any refusal or failure to sufficiently meet her affirmative duties under the MSA. The MSA purports to confer continuing subject matter jurisdiction on the trial court, but jurisdiction to adjudicate an adult child’s personal rights, ostensibly through a parent, cannot be conferred by consent, waiver or estoppel. We reverse the court’s order and remand the matter for its entry of a new order denying the father’s request for visitation and other relief under the MSA.

FACTUAL AND PROCEDURAL BACKGROUND

Ubolratana Mahidol, formerly Julie Jensen (Julie), and Peter L. Jensen (Peter) married in 1972, and Julie petitioned for dissolution of the marriage in *591 1998. The parties have three children: Ploypailin, bom in 1981; Poomi, bom in August 1983; and Sirikittiya Mai, bom in 1985. Poomi is autistic.

The parties’ MSA was incorporated into the August 2000 judgment on reserved issues. Under the MSA, the parties shared joint legal custody of the two minor children, Julie was awarded primary physical custody of them and Peter was awarded visitation. Further, the MSA acknowledged Julie’s “close ties to her parents and to the country of Thailand,” and gave her the right to move with the minor children to Thailand, subject to certain conditions affecting Poomi after he turned 18 years of age, including Peter’s continued right to visitation, and Julie’s obligations to encourage Poomi to visit Peter, to assist in the scheduling of visitation and “in carrying out all visitation schedules,” and to keep Peter informed of Poomi’s “activities, including academic, enrichment and extracurricular activities.”

The MSA also stated: Poomi “currently suffers from a disability and falls within the scope of Family Code section 3910.[ 1 ] It is possible that after he attains age 18 Poomi may continue to be incapacitated from earning a living and without sufficient means. For so long as Poomi continues to be a person within the scope of . . . Section 3910, as determined by the court, and for so long as the Superior Court . . . has jurisdiction over Poomi, it shall make such custody, visitation and support orders as are reasonable, necessary and in his best interest.” (Italics added.)

Julie moved with Poomi to Thailand in July 2001, after his graduation from Torrey Pines High School. 2 The following month Poomi turned 18 years of age. In October, Peter caused the issuance of an order to show cause regarding visitation. In a declaration, Peter stated Julie violated the MSA by not implementing visitation and by not informing him of Poomi’s “academic, social, and extra curricular [szc] development or his medical status.” Peter sought an order requiring Poomi to visit him in San Diego during Thanksgiving week.

In opposition, Julie, now represented by different counsel, argued the court lacked in personam jurisdiction and subject matter jurisdiction to make visitation orders concerning an adult child. 3 Julie unsuccessfully moved for dismissal of the order to show cause, and this court denied her petition for writ of mandate and request for stay, without prejudice to her seeking *592 appellate review of the superior court’s ruling. (Jensen v. Superior Court (Apr. 12, 2002, D039795) [summary denial order].)

At the April 2002 hearing, the court ruled the MSA gave it continuing jurisdiction over custody and visitation issues pertaining to Poomi. The court’s order provides the “court sets a four-week period of visitation, four consecutive weeks starting June 15 and concluding on or about July 13,” and the “court further orders a ten-day period in December 2002, which commences December 18 and concludes December 28.” Additionally, the court’s order requires Julie to (1) “cooperate and assist in scheduling visitation”; (2) cooperate “in carrying out this visitation by assisting Poomi in all respects by including getting him to the airport in Thailand and providing him with a person to accompany him on the flight here or in the alternative letting [Peter] receive him at the airport in Thailand, and have either him physically or one of his aides accompany Poomi over here from Thailand for the flight”; (3) “not interfere in or preclude visitation in any way and to encourage this visitation to take place”; and (4) “keep [Peter] informed once per month in writing of Poomi’s activities, including his academic enrichment and extracurricular activities.”

This court granted Julie’s petition for writ of supersedeas and request for stay of the order, pending disposition of her appeal.

DISCUSSION

I

Julie contends the trial court lacked in personam jurisdiction and subject matter jurisdiction to issue its order. These are questions of law we review independently. (Gilliland v. Medical Board (2001) 89 Cal.App.4th 208, 211-212 [ 106 Cal.Rptr.2d 863 ].)

II

“The superior court has jurisdiction in proceedings under” the Family Code. (§ 200.) “In general, ‘jurisdiction’ to adjudicate matters in a marital case involves three requirements: 1) that the court have authority to adjudicate the specific matter raised by the pleadings (subject matter jurisdiction) (see . . . § 2010); 2) that the court have ‘in rem’ jurisdiction over the marital ‘res’ to terminate marital status (‘in rem’ jurisdiction) [citation]; and 3) that the court have jurisdiction over the parties to adjudicate personal rights and obligations (personal jurisdiction).” (Muckle v. Superior Court (2002) 102 Cal.App.4th 218, 225 [ 125 Cal.Rptr.2d 303 ].)

*593 In personam jurisdiction requires a relationship between the person whose rights are at issue and the state, such as domicile or residence; due process, or notice and opportunity to be heard; and compliance with statutory requirements of process. (2 Witkin, Cal. Procedure (4th ed. 1996) Jurisdiction, § 110, p. 648.) The superior court indisputably lacked in personam jurisdiction over Poomi. Peter contends such jurisdiction was unnecessary because the court’s order does not require Poomi to visit Peter, and thus his personal rights were not adjudicated. The court, however, did order visitation. The order is titled “ORDER RE VISITATION” and states the “court sets a four-week period of visitation, four consecutive weeks starting June 15 and concluding on or about July 13,” and the “court further orders a ten-day period [of visitation] in December 2002, which commences December 18 and concludes December 28.” (Italics added.) Any order entered by a court without personal jurisdiction is void and subject to collateral attack at any time. (Rochin v. Pat Johnson Manufacturing Co. 67 Cal.App.4th 1228, 1239 [ 79 Cal.Rptr.2d 719 ].) 4

Moreover, the court lacked subject matter jurisdiction to issue its order. “Lack of jurisdiction in its most fundamental or strict sense means an entire absence of power to hear or determine the case, an absence of authority over the subject matter . . . .” (Abelleira v. District Court of Appeal (1941) 17 Cal.2d 280, 288 [ 109 P.2d 942 ]; In re Marriage of Siller (1986) 187 Cal.App.3d 36, 47 [ 231 Cal.Rptr. 757 ].) “Jurisdiction in any proceeding is conferred by law; that is, by the Constitution or by statute. Jurisdiction of the subject-matter cannot be given, enlarged, or waived by the parties.” (Harrington v. Superior Court (1924) 194 Cal. 185, 188 [ 228 P. 15 ]; Abelleira v. District Court of Appeal, supra, at p. 288; Marlow v. Campbell (1992) 7 Cal.App.4th 921, 928 [ 9 Cal.Rptr.2d 516 ]; Weil & Brown, Cal. Practice Guide: Civil Procedure Before Trial (The Rutter Group 2003), ¶ 3.2, p. 3-2; 2 Witkin, Cal. Procedure supra, Jurisdiction, §§ 6, 12, pp. 551, 556.) An order entered by a court without subject matter jurisdiction is also void and subject to collateral attack. (Rochin v. Pat Johnson Manufacturing Co., supra, 67 Cal.App.4th at p. 1239 .)

Section 2010 gives the superior court in a dissolution proceeding subject matter jurisdiction “to inquire into and render any judgment and make orders that are appropriate concerning,” among other things, the “custody of minor children of the marriage.” (§ 2010, subd. (b), italics added.) Further, section *594 3022 provides: “The court may, during the pendency of a proceeding or at any time thereafter, make an order for the custody of a child during minority that seems necessary and proper.” (Italics added; see also Muckle v. Superior Court, supra, 102 Cal.App.4th at p. 225 ; Zaragoza v. Superior Court (1996) 49 Cal.App.4th 720, 725 [ 57 Cal.Rptr.2d 1 ]; Hogoboom & King, Cal. Practice Guide: Family Law (The Rutter Group 2003) ¶ 3:4.1, pp. 3-2 to 3-3.) By statute, a minor is a person under 18 years of age. (§§ 6500, 6501.)

Visitation is a form of custody (Perry v. Superior Court (1980) 108 Cal.App.3d 480, 483 [ 166 Cal.Rptr. 583 ]), and thus under the plain terms of sections 2010, subdivision (b) and 3022 the court had no authority to issue a visitation order regarding Poomi after he reached the age of majority. “Our primary aim in construing any law is to determine the legislative intent. [Citation.] In doing so, we look first to the words of the statute, giving them their usual and ordinary meaning.” (Committee of Seven Thousand v. Superior Court (1988) 45 Cal.3d 491, 501 [ 247 Cal.Rptr. 362 , 754 P.2d 708 ].)

Further, the court lacked subject matter jurisdiction to issue the provisions of the order purportedly affecting only Julie, such as encouraging Poomi to visit Peter, facilitating visitation and keeping Peter apprised of Poomi’s activities. The orders are effectively aimed at controlling Poomi’s conduct, but as an adult he is not required to visit Peter or share information with Peter, or Julie for that matter, unless he wishes to do so. Parental authority over a child ceases by operation of law when the child reaches the age of majority (§ 7505, subd. (c)), and, accordingly, the court may neither order a party to a dissolution action to assert control over an adult child, nor hold the party responsible for any reluctance or refusal of an adult child to visit or share personal information with the other party.

The dissent criticizes us for “choos[ing] the harshest possible interpretation” of the MSA. (Dis. opn., post, at p. 601.) The dissent concludes “that following Poomi’s 18th birthday, the parties’ intent was to control only their own conduct, not Poomi’s, and that intent kept their agreement within the subject matter jurisdiction of the court.” (Dis. opn., post, at p. 602.) The dissent, however, ignores the fact that the court’s order exposes Julie to its contempt powers, should she return to California, for ostensible refusals or failures to sufficiently encourage Poomi to visit Peter, implement visitation or keep Peter apprised of Poomi’s progress and activities. Julie’s ability to comply with the MSA, of course, depends on Poomi’s cooperation. Indeed, the dissent states that because Poomi has reached 18 years of age, provisions of the MSA affecting him are “now presumptively subject to [his] consent.” (Dis. opn., post, at p. 602.) The Legislature has fixed the time when disputes between parties to a dissolution proceeding regarding custody and visitation of their children must end, and that time is when the children reach the age of majority. (§§ 2010, subd. (b), 3022.)

*595 Indeed, it appears the parties as well as the court realized from the inception that the provisions of the MSA regarding Poomi as an adult were likely unenforceable. For instance, the MSA states that “for so long as the Superior Court of the State of California, County of San Diego, has jurisdiction over Poomi, it shall make such custody, visitation and support orders as are reasonable, necessary and in his best interest.” Further, at a hearing held approximately two months after the marital settlement agreement was incorporated into the judgment on reserved issues, the court noted it would lose jurisdiction over custody and visitation issues related to Poomi when he reached 18 years of age, and perhaps the parties would continue their legal battle through probate court.

Peter contends, and the dissent appears to agree, that the court retained subject matter jurisdiction to enforce the MSA beyond Poomi’s age of majority because of the unusual circumstances. Peter asserts the degree of Poomi’s autism prevents him from communicating normally or being independent, and thus Julie’s cooperation and assistance is required to ensure visitation between Poomi and Peter. Peter points to evidence showing Poomi wishes to visit Peter in San Diego, and experts believe contact with Peter is in Poomi’s best interests.

The Family Code, however, does not authorize the court to order visitation between a party to a dissolution proceeding and a disabled adult child. The appellate record does not suggest Poomi was ever the subject of a guardianship or is now the subject of a conservatorship (see Prob. Code, § 1400 et seq.), and absent evidence to the contrary, we assume that as an adult he has the capacity to determine whether he wishes to travel to San Diego to visit Peter or share personal information with Peter. We have found no California opinion directly on point, but courts in other jurisdictions have held that in family law proceedings, the court lacks subject matter jurisdiction to issue custody or visitation orders affecting adults, and disabled adults in particular, and issues pertaining to their care must be adjudicated in conservatorship proceedings. (See, e.g., In re Marriage of Casarotto (2000) 316 Ill.App.3d 567, 570-573 [ 736 N.E.2d 1169, 1172-1174 , 249 Ill.Dec. 731 ] [court lacked jurisdiction to order visitation between father and adult child with Down’s syndrome]; Kilby v. Kilby (Jan. 28, 1999) 1999 Tenn.App. LEXIS 57 [court lacked jurisdiction to grant mother custody of adult child who was blind and mentally disabled as the result of a stroke].) 5

*596 Peter submits that since the superior court has concurrent jurisdiction to hear both probate and family law proceedings, “whether the visitation provisions of the MSA are enforced in the probate department or in the family law department is irrelevant.” The court, however, purported to act under the Family Code, and thus its authority to grant the requested relief is governed by provisions of that code. “Although this may appear unduly technical, the consequences of a contrary result are significant.” (In re Marriage of Casarotto, supra, 316 Ill.App.3d at p. 572 [ 736 N.E.2d at p. 1173 ].) For instance, the Probate Code affords a disabled adult protections unavailable under the Family Code, such as notice of a petition for conservatorship, the right to attend the hearing and contest the matter, and the rights to counsel and a trial by jury. (Prob. Code, §§ 1824, 1825, 1826.)

Additionally, Peter relies on section 3910, which the MSA cited as supposedly giving the court continuing jurisdiction over visitation. That statute provides the “father and mother have an equal responsibility to maintain, to the extent of their ability, a child of whatever age who is incapacitated from earning a living and without sufficient means.” (§ 3910, subd. (a).) The statute, however, does not bear on the court’s authority to order visitation with an adult child. Peter’s reliance on section 3587, which provides for the enforceability of an agreement for child support beyond the age of majority, is similarly misplaced as there is no corollary in the Family Code for custody or visitation.

In concluding the court properly ordered Julie’s compliance with her affirmative duties under the MSA, the dissent relies in part on “the rationale of out-of-state cases which have upheld orders requiring former spouses to pay for their adult offspring’s college education when, in the absence of divorce, the parent was likely to provide a college education.” (Dis. opn., post, at p. 603, citing Childers v. Childers (1978) 89 Wn.2d 592, 601-602 [ 575 P.2d 201, 207-208 ].) In Childers v. Childers, the lower court ordered the father to pay support for the parties’ adult children while they were attending college, and the Supreme Court of Washington upheld the order, explaining that under the state’s dissolution act the court had discretion to order child support for a “dependent” adult child. (Id. at pp. 595-596 [575 P.2d at pp. 204-205].)

*597 Childers v. Childers is inapplicable, because in California the child support obligation normally ends when the child reaches 18 years of age. (§ 6500.) 6 Parents have no legal obligation to pay for the college education of an adult child. (In re Marriage of Smith & Maescher (1993) 21 Cal.App.4th 100, 107-108 [ 26 Cal.Rptr.2d 133 ].) A parent may agree to pay for such expenses, but the court’s jurisdiction in a dissolution proceeding to enforce the agreement is statutory. (§ 3587.) Here, the court has no statutory jurisdiction to enforce the provisions of the MSA agreement, and thus the educational expenses issue is not analogous.

Likewise unavailing is Peter’s reliance on In re Marriage of Hinman (1992) 6 Cal.App.4th 711 [ 8 Cal.Rptr.2d 245 ] (Hinman). In Hinman, the wife petitioned for dissolution of marriage, listing five minor children of the marriage. The wife’s husband from a former marriage, though, fathered the two oldest children. The parties entered into a settlement agreement that gave them joint physical and legal custody of the five children, who were to continue living with the husband in the family home. The wife later moved to remove custody of the older two children from the husband, on the ground he was not their biological father and thus the court acted in excess of its jurisdiction. The trial court denied the motion, and the Court of Appeal affirmed the ruling.

The court explained that although statutorily the trial court had authority to make custody orders pertaining to children of the marriage (see § 2010, subd. (b)), the court did not lack fundamental subject matter jurisdiction, but merely acted in excess of its jurisdiction, and under principles of estoppel and waiver the wife could not attack the order on jurisdictional grounds. (Hinman, supra, 6 Cal.App.4th at p. 717 .) The court concluded that allowing the wife “to consent to a judgment awarding [the husband] joint custody and then have the unlimited power to undo that arrangement at any later time by claiming lack of jurisdiction would violate California’s strong policy in favor of preserving an established mode of child custody ‘unless some significant change in circumstances indicates that a different arrangement would be in the child’s best interest.’ [Citations.]” (Id. at pp. 718-719.)

We are not required to determine whether we agree with the Hinman court’s analysis of the subject matter jurisdiction issue, because this case is factually distinguishable. Peter seeks visitation with Poomi, an adult, but Poomi is not before the court. Further, Peter seeks to force Julie to ensure that visitation occurs, and that Peter receive personal information regarding *598 Poomi, even though she is legally powerless to comply. The public policy interest in Hinman and cases cited therein, continuing an established mode of custody, is not at issue.

We conclude the parties could not authorize the court to adjudicate Poomi’s personal interests after he turned 18 years of age. Generally,“ ‘subject matter jurisdiction cannot be conferred upon a court by consent, waiver or estoppel.’ ” (In re Marriage of Arnold & Cully (1990) 222 Cal.App.3d 499, 503 [ 271 Cal.Rptr. 624 ], citing In re Marriage of Ben-Yehoshua (1979) 91 Cal.App.3d 259, 263 [ 154 Cal.Rptr. 80 ].) The court’s order is void for lack of personal and subject matter jurisdiction. 7

DISPOSITION

The order is reversed in its entirety, and the matter is remanded to the trial court for its entry of a new order denying Peter’s request for visitation and other relief under the MSA. The stay issued on June 26, 2002, is vacated. Julie is awarded costs on appeal.

Nares, J., concurred.

Statutory references are to the Family Code unless otherwise specified.

Poomi’s sister Mai, then 16 years of age, remained in California with Peter.

Julie also argued travel to San Diego would not be in Poomi’s best interest, because he “is in excellent educational and therapeutic programs in Thailand which are supervised by leaders in the field of autism,” and his doctors agreed “that structure and continuity in Poomi’s program is essential for him.”

The dissent concludes the issue of personal jurisdiction over Poomi is not properly before this court, because Poomi has not appeared in this action and “[w]ithout some appearance on Poomi’s behalf, we have no means of determining whether he is inclined, as is his right, to confer jurisdiction on the courts of this state by way of consent.” (Dis. opn., post, at p. 604.) However, a principal issue on appeal is whether the family court had personal jurisdiction over Poomi to issue the visitation orders, and we are required to determine the issue based on the appellate record.

Julie relies on Dittrich v. Gobey (1898) 119 Cal. 599 [ 51 P. 962 ], in which the parties to a dissolution entered into an agreement under which their daughter would reside with her father until she reached 18 years of age, and then be “retumfed] to her mother.” (Id. at p. 600.) The California Supreme Court held the agreement was void because the daughter “attained her majority; her right of freedom from personal restraint was then as perfect as it could ever become; and her mother’s right to her custody was at an end.” (Id. at p. 601.) The court *596 explained a “stipulation to ‘restore’ the daughter . . . when she would be eighteen years old was as much a contract to infringe her personal liberty as if the age fixed had been thirty-six or fifty-four years, and was unlawful.” (Ibid.) Although Dittrich v. Gobey does not discuss subject matter jurisdiction, it is instructive.

However, the parents’ statutory support obligation continues for an unmarried 18-year-old child who is a full-time high school student and not self-supporting, until the child graduates or turns 19 years of age, whichever occurs first. (§ 3901, subds. (a) & (b).)

Given our holding, we are not required to address Julie’s claim the court erred by refusing to issue a statement of decision,