§ 872.520.Unknown Parties; Ownership Or Interest Unknown, Uncertain Or Contingent

Title 10.5. Partition of Real and Personal Property · Chapter 2. Commencement of Action · Article 4. Parties · Last amended 2024 · Last verified July 28, 2026

In one sentenceSection 872.520 tells the plaintiff how to handle uncertainty about interest holders -- naming unknown persons under § 872.550, stating in the complaint when ownership or share is unknown or contingent, and letting the court order additional joinder or guardians ad litem as needed.

Full Text of § 872.520

Text sizeJump to: (a) (b) (c)

(a) If the name of a person described in Section 872.510 is not known to the plaintiff, the plaintiff shall so state in the complaint and shall name as parties all persons unknown in the manner provided in Section 872.550.

(b) If the ownership or the share or quantity of the interest of a person described in Section 872.510 is unknown, uncertain, or contingent, the plaintiff shall so state in the complaint. If the lack of knowledge, uncertainty, or contingency is caused by a transfer to an unborn or unascertained beneficiary or class member, or by a transfer in the form of a contingent remainder, vested remainder subject to defeasance, executory interest, or similar disposition, the plaintiff shall also state in the complaint, so far as is known to the plaintiff, the name, age, and legal disability (if any) of the person in being who would be entitled to ownership of the interest had the contingency upon which the right of such person depends occurred prior to the commencement of the action.

(c) The court shall upon its own motion or upon motion of any party make such orders for joinder of additional parties and for appointment of guardians ad litem pursuant to Sections 372, 373, and 373.5 as are necessary or proper.

Plain-English Summary

Section 872.510 requires joining everyone with an interest, but interests aren't always neatly identifiable. This section handles two kinds of uncertainty. Subdivision (a) covers a person whose name the plaintiff doesn't know: the plaintiff states that in the complaint and names that person under § 872.550's "all persons unknown" procedure.

Subdivision (b) covers a person whose ownership share is unknown, uncertain, or contingent -- a future interest that hasn't vested, for example. The plaintiff states that uncertainty in the complaint, and where it stems from a transfer to an unborn or unascertained beneficiary, or from a contingent remainder, a vested remainder subject to defeasance, an executory interest, or a similar disposition, the plaintiff also has to state, so far as known, the name, age, and any legal disability of whoever would take the interest if the contingency had already occurred before the action began.

Subdivision (c) backstops both situations: the court can, on its own motion or any party's motion, order additional parties joined and guardians ad litem appointed under §§ 372, 373, and 373.5 as necessary or proper -- ensuring that minors, incapacitated persons, or others needing representation aren't left unprotected just because their interest is hard to pin down.

Frequently Asked Questions

What if I don't know the name of a person with an interest in the property?

State that in the complaint and join that person as an unknown party under § 872.550.

What if it's unclear how much of an interest someone owns, or whether their interest will ever vest?

Section 872.520(b) requires stating that uncertainty in the complaint, along with details about the person who would take the interest if the contingency had already occurred, when the uncertainty stems from certain kinds of future interests.

Can the court appoint a guardian ad litem for someone with an uncertain or contingent interest?

Yes, subdivision (c) lets the court order joinder of additional parties and appointment of guardians ad litem under §§ 372, 373, and 373.5 as necessary.

Amendment History

Amended by Stats 2023 ch 260 (SB 345),s 8, eff. 1/1/2024. Added by Stats. 1976, Ch. 73.

Source & verification. Section text is reproduced verbatim from the Deering's California Codes Annotated / vLex. Enacted by the California Legislature. Last verified July 28, 2026. · Official source

Also known as: unknown or contingent interest holders partition californiaguardian ad litem partition action