Key Takeaways

• A trustee is a fiduciary — legally bound to administer the trust loyally, impartially, prudently, and solely in the beneficiaries’ interest.
• A breach is any violation of those duties: self-dealing, mismanagement, favoritism, commingling, failing to account, or unreasonable delay.
• Beneficiaries can seek a range of remedies — compelling the trustee to repair the harm, surcharge (personal liability), removal, disgorging improper gains, and more.
• The measure of liability can include lost value, lost profits, and interest.
• Beneficiaries can even pursue breaches a trustee committed while the settlor was alive, once the trust becomes irrevocable.

What a Trustee Owes

A trustee holds and manages someone else’s property for the benefit of others. The law calls this a fiduciary relationship, and it carries the highest standard of conduct the law recognizes. A trustee must put the beneficiaries’ interests first, administer the trust according to its terms, stay loyal, treat beneficiaries fairly, manage the assets prudently, and account for everything they do. They’re handling the beneficiaries’ inheritance, and the law expects them to do it as carefully as a prudent person managing another’s affairs — not as casually as they might handle their own.

When a trustee falls short, the consequences are serious, because the breach harms people who were depending on them. California gives beneficiaries real tools to respond — and real remedies to recover what was lost.

The Core Fiduciary Duties

A trustee’s duties include:

• Loyalty — administering the trust solely in the beneficiaries’ interest, never for the trustee’s own benefit.
• Avoiding self-dealing and conflicts — not buying trust assets, lending to themselves, or putting their interests against the beneficiaries’ without proper authority.
• Impartiality — treating beneficiaries even-handedly, not favoring one (such as a current-income beneficiary over a remainder beneficiary, or one sibling over the rest).
• Prudent administration — managing and investing the assets with reasonable care, under California’s prudent investor standard.
• Keeping assets separate — not commingling trust property with the trustee’s own.
• Informing and accounting — keeping beneficiaries reasonably informed and providing the accountings the law requires.

These duties are the yardstick. A breach is simply a violation of one or more of them, and most trust disputes come down to identifying which duty was broken and what it cost the trust.

What a Breach Looks Like

In practice, trustee breaches recur in recognizable patterns:

• Self-dealing — selling trust property to themselves or an associate below value, paying themselves improper or excessive fees, using trust funds personally.
• Mismanagement — reckless or negligent investing, letting property deteriorate, failing to collect what’s owed, leaving assets unprotected.
• Favoritism — steering benefits to themselves or a favored beneficiary at others’ expense.
• Commingling — mixing trust funds with their own, making it impossible to trace what happened.
• Failure to account or inform — refusing to provide accountings, hiding transactions, stonewalling reasonable requests.
• Unreasonable delay — sitting on the administration, withholding distributions without justification.

Not every misstep is a breach. Trustees are allowed honest, reasonable judgment, and a single good-faith mistake usually isn’t actionable. But a serious lapse, a clear conflict, or a pattern of carelessness crosses the line — and negligent mishandling, while it may be a breach, is different from the bad-faith conduct that triggers the harshest penalties (a distinction that matters for double damages).

Suspect a trustee is mishandling assets or hiding the ball? Beneficiaries have stronger rights than they often realize. Bay Legal handles trustee-breach matters throughout California. For guidance on your specific situation, call (650) 668-8000 or schedule a consultation at baylegal.com/contact.

The Remedies — What Beneficiaries Can Recover

This is where fiduciary law has teeth. When a beneficiary proves a breach, California courts can order a range of remedies, including:

• Compelling the trustee to perform their duties or to redress a breach by paying money or restoring property.
• Surcharge — holding the trustee personally liable for the loss the breach caused. See our guide on trustee surcharge.
• Disgorging improper gains — making the trustee give up any profit they made through the breach.
• Tracing and recovering property, including imposing an equitable lien or constructive trust on assets the trustee took.
• Removing the trustee and appointing a successor.
• Reducing or denying compensation, and in some cases awarding attorney fees.
• Appointing a receiver to protect the trust in serious cases.

The measure of liability can include the loss in value the breach caused, any profit the trustee made, and lost profits the trust would have earned but for the breach — sometimes with interest. In short, a trustee who breaches can be made to restore the trust to where it should have been, out of their own pocket. For egregious conduct — especially involving an elder or a bad-faith taking — additional remedies including double damages may apply.

Breaches Committed While the Settlor Was Alive

A powerful point many beneficiaries don’t know: when a trust was revocable and the settlor has died, beneficiaries can pursue breaches the trustee committed while the settlor was still alive, to the extent those breaches harmed the beneficiaries’ interests. The California Supreme Court has confirmed that a trustee who mismanaged a revocable trust during the settlor’s life can be held to account by the beneficiaries after the settlor’s death. This matters because much of the damage in trust cases happens during a settlor’s final, vulnerable years — and the law doesn’t let a trustee escape responsibility simply because the misconduct predated the settlor’s death.

Discovered that a trustee mismanaged the trust — even during a parent’s lifetime? That conduct may still be actionable. Bay Legal can assess it. For guidance on your specific situation, call (650) 668-8000 or schedule a consultation at baylegal.com/contact.

Proving a Breach

Trustee-breach cases are won on records and reconstruction. Building one typically means:

• Getting an accounting — often the first step is compelling the trustee to account, which forces the transactions into the open.
• Tracing the assets — following the money to show what happened versus what should have.
• Documenting the duty and the breach — establishing what the trustee was required to do and how they deviated.
• Quantifying the loss — proving the dollar harm, including lost value and lost profits.

A trustee who’s been hiding misconduct often can’t withstand a court-ordered, line-by-line accounting — which is why a refusal to account is both a breach in itself and a major red flag.

A Note for Trustees

If you’re a trustee, these duties are your roadmap for staying out of trouble — and your defense if you’re accused. A trustee who administers loyally, invests prudently, keeps trust property separate, documents decisions, and accounts properly is well positioned to defend a breach claim. Many claims fail because the conduct was honest judgment, not breach. And a proper accounting even starts the clock on the time beneficiaries have to challenge disclosed transactions. See our guide on defending a trustee.

How This Fits Together

Breach of fiduciary duty is the engine behind trustee removal and surcharge, and it overlaps with financial elder abuse and double-damages claims. The duties it enforces are the beneficiary rights covered in our companion hub. For the litigation process overall.

Frequently Asked Questions

What is breach of fiduciary duty by a trustee?

It’s a violation of the duties a trustee owes — loyalty, impartiality, prudence, avoiding self-dealing, keeping assets separate, and accounting. Common breaches include self-dealing, mismanagement, favoritism, commingling, and refusing to account.

Can you sue a trustee for breach of fiduciary duty in California?

Yes. A beneficiary can petition the probate court to compel the trustee to redress the breach, surcharge them for losses, remove them, disgorge improper gains, and recover with interest.

What can a beneficiary recover for a trustee’s breach?

The loss in value the breach caused, any profit the trustee made improperly, lost profits the trust should have earned, and interest. In bad-faith or elder-abuse cases, additional remedies including double damages may apply.

Can a trustee be liable for things they did while the settlor was alive?

Yes. Once a revocable trust becomes irrevocable on the settlor’s death, beneficiaries can pursue breaches the trustee committed during the settlor’s lifetime, to the extent they harmed the beneficiaries’ interests.

Is every mistake a breach of fiduciary duty?

No. Trustees are allowed reasonable, good-faith judgment, and an honest mistake usually isn’t actionable. A serious lapse, a clear conflict, or a pattern of misconduct is what crosses into breach.