What Is Tortious Interference? Elements of Interference With Contract and Economic Advantage in California

What Is Tortious Interference Under California Law?

Tortious interference is a civil claim against someone who intentionally disrupts your contract or business relationship with a third party. California recognizes two main versions. Intentional interference with contractual relations protects an existing contract, and requires proof of five elements: a valid contract, the defendant's knowledge of it, intentional acts designed to cause a breach or disruption, an actual breach or disruption, and resulting damage. Intentional interference with prospective economic advantage protects a business relationship that has not yet become a binding contract, and adds a sixth requirement: the defendant's conduct must have been independently wrongful — unlawful for some reason other than the interference itself.

The word "tortious" simply means the conduct is a tort — a civil wrong that gives the injured party a right to sue for damages. The claim exists because a contract is only as valuable as the other side's willingness to perform it. When an outsider persuades your customer, supplier, distributor, or business partner to walk away, the law of contracts alone may not reach the person responsible, because that outsider never signed anything with you. Tortious interference fills that gap by making the outsider answerable for the harm.

At the same time, California courts are careful not to let the tort swallow ordinary competition. Businesses compete for the same customers, employees, and deals every day, and winning business away from a rival is not a wrong in itself. Much of the law in this area is about drawing that line: protecting relationships that are already secured by contract, while leaving room for fair competition over relationships that are still up for grabs. Interference claims arise most often in business litigation, and frequently travel together with claims for breach of contract, trade secret misappropriation, or fraud and misrepresentation.

What Are the Elements of Intentional Interference With Contractual Relations?

The California Supreme Court set out the elements in Pacific Gas & Electric Co. v. Bear Stearns & Co. (1990) 50 Cal.3d 1118. To prevail, a plaintiff must prove:

1. A valid contract between the plaintiff and a third party.
2. The defendant's knowledge of that contract.
3. Intentional acts designed to induce a breach or disruption of the contractual relationship.
4. Actual breach or disruption of the contractual relationship.
5. Resulting damage to the plaintiff.

The first element requires an enforceable agreement. If the "contract" was never formed, was void, or existed only as a hope, the claim for interference with contract fails — although the facts may still support the separate claim for interference with prospective economic advantage discussed below.

The second and third elements concern the defendant's state of mind. The defendant must have known the contract existed; a stranger who had no idea a deal was in place cannot be said to have interfered with it intentionally. On intent, the plaintiff does not have to prove that disrupting the contract was the defendant's goal. In Korea Supply Co. v. Lockheed Martin Corp. (2003) 29 Cal.4th 1134, the California Supreme Court explained that the intent requirement is satisfied if the defendant knew the interference was certain or substantially certain to occur as a result of its actions.

The fourth element is broader than many people expect. A completed breach is not required. In Pacific Gas & Electric, the Court acknowledged that interference which makes enjoyment of a contract more expensive or burdensome may be actionable. A defendant who causes the other contracting party to slow-walk performance, or who drives up the plaintiff's cost of performing, can be liable even if the contract technically survives.

Finally, the plaintiff must show damage caused by the interference — typically the profits the contract would have produced, or the added cost and expense the disruption imposed.

What Are the Elements of Interference With Prospective Economic Advantage?

When there is no binding contract yet — a customer who has bought from you for years without a written agreement, a deal that is close but not signed, an expected renewal — the claim is intentional interference with prospective economic advantage. As stated in Korea Supply, its elements are:

1. An economic relationship between the plaintiff and a third party, with the probability of future economic benefit to the plaintiff.
2. The defendant's knowledge of the relationship.
3. Intentional acts on the part of the defendant designed to disrupt the relationship.
4. Actual disruption of the relationship.
5. Economic harm to the plaintiff proximately caused by the defendant's acts.

On top of these five elements, the plaintiff must prove that the defendant's conduct was independently wrongful. The California Supreme Court adopted this requirement in Della Penna v. Toyota Motor Sales, U.S.A., Inc. (1995) 11 Cal.4th 376, holding that a plaintiff must show the defendant engaged in conduct that was wrongful by some legal measure other than the fact of interference itself. Korea Supply then defined the standard: an act is independently wrongful if it is unlawful — that is, if it is proscribed by some constitutional, statutory, regulatory, common law, or other determinable legal standard. An improper motive alone is not enough.

In practice, the independently wrongful act is often a separate tort or statutory violation: fraud or misrepresentation to the third party, defamation of the plaintiff, misuse of trade secrets, bribery, or another violation of law. The first element is also a meaningful filter. Korea Supply explains that the tort protects the expectation that an existing relationship will eventually yield its benefit — not the more speculative hope that a beneficial relationship might someday arise.

Interference With Contract vs. Prospective Economic Advantage

The two claims share most of their elements, and the difference between them matters. California gives existing contracts more protection than mere business expectancies. As the Supreme Court put it in Korea Supply, intentionally interfering with an existing contract is a wrong in and of itself, while intentionally interfering with prospective economic advantage is not. The practical result is summarized below.

Issue	Interference With Contract	Interference With Prospective Economic Advantage
What is protected	An existing, valid contract	An economic relationship likely to produce future benefit
Intent	Knowledge that disruption is certain or substantially certain is enough	Same intent standard
Independently wrongful act required?	No (except for at-will contracts, discussed below)	Yes
Key California authority	Pacific Gas & Electric Co. v. Bear Stearns & Co. (1990)	Della Penna (1995); Korea Supply (2003)

Can You Sue for Interference With an At-Will Contract?

Many valuable relationships are terminable at will — employment relationships, month-to-month service arrangements, and distribution deals without a fixed term. In Reeves v. Hanlon (2004) 33 Cal.4th 1140, the California Supreme Court held that inducing the termination of an at-will employment relationship may be actionable, but only under the standard that applies to interference with prospective economic advantage. To recover, the plaintiff must plead and prove that the defendant engaged in an independently wrongful act that induced the at-will employee to leave. The Court explained that this standard guards against unlawful methods of competition in the job market while promoting the right of at-will employees to pursue better opportunities and the right of employers to compete for talented workers. Merely soliciting or hiring another company's at-will employee is not, by itself, an actionable wrong.

Who Can Be Liable for Tortious Interference?

Interference is a claim against an outsider to the relationship. A party to a contract cannot be sued in tort for interfering with its own contract; its remedy is a claim for breach. In Applied Equipment Corp. v. Litton Saudi Arabia Ltd. (1994) 7 Cal.4th 503, the California Supreme Court refused to let a plaintiff convert a contract dispute into a tort case by alleging that the other contracting party conspired to interfere with its own contract. The distinction matters because tort claims can carry remedies, including punitive damages, that are generally unavailable for a simple breach of contract.

What Damages Can You Recover for Tortious Interference?

A successful plaintiff can recover compensatory damages for the harm the interference caused — most often the lost profits from the disrupted contract or relationship, along with added costs incurred because of the disruption. Because interference is an intentional tort, punitive damages may also be available under Civil Code Section 3294 when the plaintiff proves by clear and convincing evidence that the defendant acted with oppression, fraud, or malice. Where the interference is ongoing, a court may also be asked to stop it through an injunction or temporary restraining order.

The Statute of Limitations

Interference claims are subject to a short deadline. California courts commonly apply the two-year limitations period of Code of Civil Procedure Section 339(1), which governs actions on an obligation or liability not founded upon an instrument in writing. Because the start date of the period can be disputed — and because related claims, such as fraud or breach of a written contract, carry different deadlines — anyone who suspects interference should get advice promptly rather than assume more time remains.

Defenses to a Tortious Interference Claim

Most defenses attack one of the elements. A defendant may show there was no valid contract, that it did not know of the contract or relationship, that the third party's decision was not caused by the defendant's conduct, or that the plaintiff suffered no damage. For prospective-advantage and at-will claims, the most important defense is often that the defendant did nothing independently wrongful — it simply competed. As the Court observed in Korea Supply, quoting Della Penna, the law usually takes care to draw lines of legal liability in a way that maximizes areas of competition free of legal penalties.

Litigation itself is generally not a basis for liability. In Pacific Gas & Electric, the Supreme Court held that it is not proper to impose interference liability for inducing a potentially meritorious lawsuit. And as noted above, a defendant who is a party to the contract cannot be sued for interfering with it. Finally, the statute of limitations can bar an otherwise valid claim that was filed too late.

Whether you are trying to hold a competitor responsible for taking your business or defending against an accusation of interference, these cases turn on documents and timing: what the contract said, what the defendant knew and when, what was said to the third party, and whether any independently wrongful conduct can be proven. Careful early investigation is usually the difference between a claim that survives and one that does not.