Intervention is the procedure whereby someone not named as a party to an action (or ordered joined as a party) may nevertheless become a party. (Code of Civ. Proc., § 387.) “The purpose of allowing intervention is to promote fairness by involving all parties potentially affected by a judgment.” (Simpson Redwood Co. v. State of California (1987) 196 Cal.App.3d 1192, 1199.)

How to Structure the Motion

“An intervention takes place when a nonparty, deemed an intervenor, becomes a party to an action or proceeding between other persons by doing any of the following:

1. Joining a plaintiff in claiming what is sought by the complaint.
2. Uniting with a defendant in resisting the claims of a plaintiff.”

(Code of Civ. Proc., § 387(b).)

There are two types of interventions (mandatory and permissive), both of which require that the party seeking to intervene have an interest in the action. (Hodge v. Kirkpatrick Development, Inc. (2005) 130 Cal.App.4th 540, 546, 554.)

Mandatory Intervention

With regards to mandatory intervention, “[t]he court shall, upon timely application, permit a nonparty to intervene in the action or proceeding if either of the following conditions is satisfied:

1. A provision of law confers an unconditional right to intervene.
2. The person seeking intervention claims an interest relating to the property or transaction that is the subject of the action and that person is so situated that the disposition of the action may impair or impede that person’s ability to protect that interest, unless that person’s interest is adequately represented by one or more of the existing parties.”

(Code of Civ. Proc., § 387(d)(1).)

Permissive Interventions

In contrast, permissive intervention allows that “[t]he court may, upon timely application, permit a nonparty to intervene in the action or proceeding if the person has an interest in the matter in litigation, or in the success of either of the parties, or an interest against both.” (Code of Civ. Proc., § 387(d)(2); Fireman’s Fund Ins. Co. v. Gerlach (1976) 56 Cal.App.3d 299, 303-305; U.S. Ecology, Inc. v. State of Calif. (2001) 92 Cal.Ap.4th 113, 140; City & County of San Francisco v. State of Calif. (2005) 128 Cal.App.4th 1030, 1037.)

To establish a direct and immediate interest in the litigation for purposes of permissive intervention, a non-party seeking intervention must show that he or she stands to gain or lose by direct operation of the judgment, even if no specific interest in the property or transaction at issue exists. Simpson Redwood Co. v. State of California (1987) 196 Cal.App.3d 1192, 1201. The party need not have any pecuniary interest in the dispute. Simpson Redwood Co. v. State of Calif. (1987) 196 Cal.App.3d 1192, 1201.

The Court’s Decision

“[T]he trial court has discretion to permit a nonparty to intervene where the following factors are met:

1. the proper procedures have been followed;
2. the nonparty has a direct and immediate interest in the action;
3. the intervention will not enlarge the issues in the litigation; and
4. the reasons for the intervention outweigh any opposition by the parties presently in the action.”

(Reliance Ins. Co. v. Super. Ct., 84 Cal.App.4th 383, 386 (2000).)

“A person has a direct interest justifying intervention in litigation where the judgment in the action of itself adds to or detracts from his legal rights without reference to rights and duties not involved in the litigation.” (City and County of San Francisco v. State (2005) 128 Cal.App.4th 1030, 1037.)

“In order that a party may be permitted to intervene it is not necessary that his interest in the action be such that he will inevitably be affected by the judgment. It is enough that there be a substantial probability that his interests will also be so affected.” (Timberidge Enterprises, Inc. v. City of Santa Rosa (1978) 86 Cal.App.3d 873, 881-82. Even where intervention is permissive, the statute is to be liberally construed in favor of intervention. See Lindelli v. Town of San Anselmo, 139 Cal.App.4th 1499, 1505 (2006).)

However, a trial court has discretion to deny intervention even when a “direct interest” is shown, if the interests of the original litigants outweigh the intervenor’s concerns. (Marriage of Kerr (1986) 185 Cal.App.3d 130, 134; City of Malibu v. California Coastal Comm’n. (2005) 128 Cal.App.4th 897, 906.) But a proposed intervenor’s interest is insufficient “when the action in which intervention is sought does not directly affect it although the results of the action may indirectly benefit or harm its owner.” (Lindelli v. Town of San Anselmo (2006) 139 Cal.App.4th 1499, 1505.)

Statute of Limitations

Whether intervention is mandatory and permissive, the party seeking to intervene must make “timely” application to the court. (Code of Civ. Proc., § 387(a).) “Aside from the statutory limitation... it is the general rule that a right to intervene should be asserted within a reasonable time and that the intervener must not be guilty of an unreasonable delay after knowledge of the suit.” (Allen v. Cal. Water & Tel. Co. (1947) 31 Cal.2d 104, 108.)

However, “[t]imeliness is hardly a reason to bar intervention when a direct interest is demonstrated and the real parties in interest have not shown any prejudice other than being required to prove their case.” (See Truck Ins. Exch. v. Super. Ct. (1997) 60 Cal.App.4th 342, 351.) “[T]he timeliness of a motion to intervene under section 387 should be determined based on the date the proposed interveners knew or should have known their interests in the litigation were not being adequately represented.” (Ziani Homeowners Assn. v. Brookfield Ziani LLC (2015) 243 Cal.App.4th 274, 282.)