Burden of Proof in a California Civil Case: Preponderance, Clear and Convincing

Last updated: November 2026

The burden of proof in a California civil case is a party's obligation to prove each fact essential to its claim or defense. Unless a statute says otherwise, the standard is a preponderance of the evidence: the fact is more likely true than not. A higher standard, clear and convincing evidence, applies to certain claims such as punitive damages. Kolmogorov Law, P.C. tries and settles business cases under both standards in Orange County, Los Angeles, and across California.

Call (909) 235-6116 or contact us online to discuss what you will need to prove.

What the burden of proof means

The Evidence Code defines the burden of proof as a party's obligation to establish, by evidence, a requisite degree of belief about a fact in the mind of the judge or jury. (Evid. Code, § 115.)

Lawyers split the concept into two burdens. The burden of persuasion is the one just described: convincing the factfinder to the required degree. The burden of producing evidence is narrower. It sits initially on the party with the burden of proof and shifts to the other side once enough evidence is in to require a finding against it. (Evid. Code, § 550, subds. (a), (b).)

Preponderance of the evidence: the civil default

Except where the law provides otherwise, the burden of proof requires proof by a preponderance of the evidence. (Evid. Code, § 115.) That is the standard in nearly every business case: breach of contract, breach of fiduciary duty, most fraud claims, unfair competition, and trade secret misappropriation.

The jury instruction puts it plainly. A party must persuade the jury that what it is required to prove is more likely to be true than not true. If the jury cannot decide that something is more likely true than not, the party did not prove it. (CACI No. 200.) Our civil jury instructions page explains how these instructions are used.

A tie goes to the party without the burden.

I have seen owners lose cases they should have won because they assumed the other side needed to prove something close to guilt. It does not. It needs to be slightly more believable than you.

Clear and convincing evidence

Some findings require more. Clear and convincing evidence means the factfinder must conclude that it is highly probable that the fact is true. (CACI No. 201.)

In business litigation the most common example is punitive damages. A plaintiff seeking them must prove by clear and convincing evidence that the defendant acted with oppression, fraud, or malice. (Civ. Code, § 3294, subd. (a).) A plaintiff can win a fraud claim by a preponderance and still fall short of punitive damages because the proof of malice was not strong enough. Our fraud claims guide covers how those cases are built.

Who carries the burden on what

The rule is simple to state. A party has the burden of proof as to each fact essential to the claim or defense it is asserting. (Evid. Code, § 500.)

For a plaintiff suing on a contract, that means proving the contract, its own performance or excuse, the defendant's breach, and the resulting damages. For a plaintiff alleging fraud, it means each element of the misrepresentation, knowledge, intent, reliance, and harm.

The defendant carries its own burdens. Affirmative defenses such as the statute of limitations, waiver, or an offset belong to the party raising them.

A distributor claims a manufacturer promised exclusive territory. There is no signed document. The distributor bears the burden of proving the oral promise and its terms, and if the evidence is one person's word against another's with nothing to tip the balance, the distributor loses.

A buyer claims the seller of a business inflated revenue. The buyer must prove the misstatement and its own reliance by a preponderance. If it also wants punitive damages, it must separately prove malice or fraud to the clear and convincing standard.

The burden before trial: summary judgment

The burden of proof also governs motions for summary judgment. A defendant moving for summary judgment meets its initial burden by showing that one or more elements of a claim cannot be established. The burden then shifts to the plaintiff to show a triable issue of material fact with specific evidence, not the allegations in its pleading. (Code Civ. Proc., § 437c, subd. (p)(2).) A plaintiff moving for summary judgment must prove each element of its claim before the burden shifts. (Code Civ. Proc., § 437c, subd. (p)(1).)

The Supreme Court has described this as a burden of production that shifts, while the burden of persuasion stays with the moving party throughout. (Aguilar v. Atlantic Richfield Co. (2001) 25 Cal.4th 826, 850.) Our summary judgment guide explains how the motion works in a business case.

What this means for your evidence

Because the standard is comparative, the quality of the record decides most cases. Contemporaneous emails beat recollection. A signed change order beats a conversation in a parking lot.

Preserve everything early, including the messages that look bad. Our litigation hold guide covers how. A party caught deleting evidence hands the other side an inference it would otherwise have to earn.

Cases that go to trial are heard in the Superior Court, for Orange County usually at the Central Justice Center in Santa Ana and for Los Angeles at the Stanley Mosk Courthouse. Our civil trials page describes how evidence is presented.

What to bring to the first meeting

Bring the documents that prove each element of your claim or defense: the contract, the communications, the invoices, and the payment records. Bring the documents that hurt you as well, because we need to weigh them. Bring a list of witnesses who can confirm the key facts. If you are seeking punitive damages, bring whatever shows the other side knew what it was doing.

Frequently asked questions

What is the burden of proof in a civil case?

In California, the burden of proof in a civil case is usually a preponderance of the evidence, which means the party with the burden must show that each essential fact is more likely true than not. Some findings, such as punitive damages, require clear and convincing evidence, meaning the fact is highly probable. The party asserting a claim or defense carries the burden on its elements.

What does preponderance of the evidence mean?

It means the evidence on one side outweighs the evidence on the other, even slightly. The jury is instructed that a party must prove its claim is more likely to be true than not true. It is the lowest standard of proof used in court, and it applies to most business disputes, including breach of contract and ordinary fraud claims.

What is clear and convincing evidence?

Clear and convincing evidence requires the factfinder to conclude that a fact is highly probable, not merely more likely than not. California applies it to punitive damages and to a limited set of other claims and findings. It sits between preponderance and the criminal standard of proof beyond a reasonable doubt.

Who has the burden of proof in a breach of contract case?

The plaintiff must prove the contract, its own performance or a valid excuse for not performing, the defendant's breach, and the damages caused by the breach, each by a preponderance of the evidence. The defendant bears the burden on any affirmative defense it raises, such as the statute of limitations, waiver, or the plaintiff's own prior breach.

Is the burden of proof different in federal court?

For claims under California law, no. A federal court sitting in diversity applies California's standards of proof to state-law claims, so a breach of contract case in the Central District of California is tried under the same preponderance standard as in the Superior Court.

Talk to a California civil litigation attorney

If you need to understand what your case will require you to prove, call (909) 235-6116 or contact us online. Kolmogorov Law, P.C. is located at 327 Magnet, Irvine, CA 92618, and represents businesses in Orange County, Los Angeles, and throughout California.

This page provides general information about California law and is not legal advice. Outcomes depend on the evidence, the facts, and the court.