Aiding and Abetting Breach of Fiduciary Duty: California Elements

In California, you can sue a third party for aiding and abetting a breach of fiduciary duty when that person or company knowingly gave substantial help to a fiduciary who violated their duties to you. The claim has four elements: a fiduciary breached their duties, the defendant had actual knowledge of the breach, the defendant gave substantial assistance or encouragement, and that assistance was a substantial factor in causing your harm.¹ The framework comes from California’s civil jury instruction CACI No. 3610 and was confirmed by the Court of Appeal in Nasrawi v. Buck Consultants LLC (2014).

The value of the claim is practical. When the fiduciary who actually harmed you has disappeared, gone bankrupt, or spent the money, the aiding and abetting theory lets you reach the bank, accountant, lawyer, or business partner who helped them do it. California treats the aider and abettor as a cotortfeasor who is equally liable with the primary wrongdoer, so a solvent third party can be on the hook for the full loss.¹

The Underlying Breach Has to Be Real

Without an actual breach by a fiduciary, the claim against the third party collapses. You need to identify the fiduciary relationship, the specific duties it created, and the specific conduct that violated them. Self-dealing, misappropriating funds, hiding conflicts of interest, or failing to disclose material information are common examples. This element usually is not where these cases turn, but the breach has to be pleaded and proved with the same care as any direct fiduciary duty claim.

Actual Knowledge Is Where Most Claims Fail

California requires proof that the defendant had actual knowledge of the fiduciary’s breach. Suspicion is not enough. Access to information that should have raised red flags is not enough. The defendant has to have been consciously aware that the fiduciary was violating their duties.¹

The leading case is Casey v. U.S. Bank National Association (2005), which held that a defendant “can only aid and abet another’s tort if the defendant knows what that tort is.” A bank’s general awareness that its customers were involved in wrongful conduct did not satisfy the element. The plaintiff needed to show the bank had actual knowledge that the specific fiduciaries were misappropriating specific funds.²

Defendants rarely put their awareness in writing. In practice, knowledge is proven through circumstantial evidence: emails and other communications that reveal what the defendant understood, the depth of their involvement in the transaction, how unusual the transaction was compared with the defendant’s ordinary business, and whether the defendant received a benefit that only makes sense if they knew what was going on. California courts have not clearly adopted a willful blindness standard for these claims, so building the case around what the defendant actually knew is the safer path.

Substantial Assistance and Causation

Knowing about a breach and failing to stop it is not aiding and abetting. The CACI instruction is explicit: “Mere knowledge that a tort is being committed and the failure to prevent it does not constitute aiding and abetting.”³ The defendant has to have actively helped or encouraged the breach.

What counts as help is broader than you might expect. The Casey court noted that even ordinary business transactions, like routine banking services, can qualify as substantial assistance if the provider actually knew those transactions were helping the customer commit a specific tort.² The character of the act matters less than what the defendant knew they were facilitating. Courts look at the nature of the assistance, its magnitude, the defendant’s relationship to the fiduciary, and whether their participation made the breach materially more likely to succeed.

Causation overlaps with this inquiry. The assistance must have been a substantial factor in causing your harm. If the fiduciary would have committed the same breach the same way without the defendant’s help, causation fails.¹

Who Can Be Sued as an Aider and Abettor

The defendant is always a non-fiduciary third party. The fiduciary who committed the breach is sued directly for the breach itself; the third party is sued for helping it happen. Typical defendants include banks that processed suspicious transfers, accountants who structured improper transactions, attorneys who facilitated self-dealing, and business partners who participated in diverting assets.

One important limit: employees or agents of the fiduciary acting solely within the scope of their employment generally cannot be held liable as aiders and abettors. A supervisor is not automatically liable for a subordinate’s acts, and mere knowledge plus a failure to intervene does not cross the line.¹ If an agent steps outside the scope of their role and actively participates in the breach with knowledge, that protection disappears.

How to Plead the Claim

Getting past a demurrer is a common stumbling block. You need to allege facts supporting each of the four elements with enough specificity to put the defendant on notice. Vague allegations that a defendant was “involved in” or “aware of” wrongdoing will not survive a challenge. The Casey court dismissed claims against banks in part because the plaintiff alleged only general awareness of wrongful conduct rather than actual knowledge of the specific breach.²

Some California cases suggest a plaintiff may also need to allege that the defendant had specific intent to facilitate the wrongful conduct, not just that they knowingly helped. In Nasrawi, the court flagged this as an open question but found the complaint sufficient because its allegations could fairly be read to indicate the defendant intended to participate in the breach.¹ The safest drafting approach is to plead both knowledge and intent explicitly, with concrete facts behind each.

How Long You Have to Sue

The statute of limitations for aiding and abetting a breach of fiduciary duty tracks the limitations period for the underlying breach. For most fiduciary duty claims in California, that is four years under Code of Civil Procedure section 343, the state’s catch-all limitations statute.⁴

If the breach amounts to actual or constructive fraud, the period shrinks to three years under Code of Civil Procedure section 338(d). Courts look at the substance of the claim rather than the label. If the gravamen of the complaint is that the fiduciary engaged in fraud, the three-year period applies even when the pleading calls it a breach of fiduciary duty.⁵

California’s delayed discovery rule can extend these deadlines. When a fiduciary conceals the breach or you had no reasonable way to learn about it, the clock does not start until you discovered, or reasonably should have discovered, the facts giving rise to the claim. That tolling matters especially in fiduciary cases, where the injured party often trusts the wrongdoer and has limited visibility into what is happening with their money or property.

What You Can Recover

A plaintiff who proves all four elements can seek several kinds of relief from the aider and abettor.

Compensatory damages cover the actual financial harm caused by the breach, including lost profits and the value of misappropriated property, with the aim of putting you back in the position you would have been in absent the breach.

Disgorgement makes the defendant give up profits they earned through their participation. It is useful when your own losses are hard to quantify but the defendant’s gains are clear.

A constructive trust is an equitable remedy in which the court declares that the defendant holds specific property for your benefit. This helps when identifiable assets can still be traced back to the breach.

Punitive damages are available when the conduct involved malice, oppression, or fraud. California Civil Code section 3294 requires clear and convincing evidence, a higher standard than the preponderance standard for the underlying claim. Malice under the statute means conduct intended to injure or despicable conduct carried out with willful and conscious disregard for others’ rights; fraud means intentional misrepresentation or concealment of a material fact.⁶

Prejudgment interest may also be awarded at the court’s discretion. California Civil Code section 3288 permits interest on damages arising from non-contractual obligations, including breach of fiduciary duty, which can meaningfully increase a recovery when the breach happened years before judgment.⁷

One Boundary: Federal Securities Cases

If the fiduciary’s breach involved securities transactions, do not assume you can sue the third party under federal law. The U.S. Supreme Court held in Central Bank of Denver, N.A. v. First Interstate Bank of Denver, N.A. (1994) that private plaintiffs cannot bring aiding and abetting claims under Section 10(b) of the Securities Exchange Act. Only the SEC can pursue aiding and abetting liability for federal securities violations.⁸ That closed federal door makes California’s state-law tort the practical route for private plaintiffs whose fiduciary breach touches investment fraud, corporate self-dealing, or the securities markets.

1
Justia. CACI No. 3610 Aiding and Abetting Tort – Essential Factual Elements – Section: Sources and Authority
2
Justia Law. Casey v US Bank Natl Assn – California Court of Appeal (2005)
3
Justia. CACI No. 3610 Aiding and Abetting Tort – Essential Factual Elements
4
California Legislative Information. California Code of Civil Procedure CCP 343
5
Justia. CACI No. 4120 Affirmative Defense – Statute of Limitations
6
California Legislative Information. California Civil Code 3294
7
California Legislative Information. California Civil Code 3288
8
Legal Information Institute. Central Bank of Denver NA v First Interstate Bank of Denver NA