Can I Sue a Family Member for Breach of Fiduciary Duty?

Table of Contents

Key Takeaways

When a Family Member Owes You a Fiduciary Duty

What Counts as a Breach of Fiduciary Duty

Common Family Situations Where Fiduciary Duties Arise

How to Prove a Breach of Fiduciary Duty in California

When Suing a Family Member Becomes Necessary

Consequences for Breaching a Fiduciary Duty

Related Resources

FAQ

How The Grossman Law Firm Can Help

• Family members can owe fiduciary duties in California when they serve as trustees, executors, agents under a power of attorney, guardians, or business partners.
• A breach occurs when the fiduciary acts in their own interest rather than the beneficiary’s, or fails to meet California’s legal standards of loyalty, prudence, and full disclosure.
• You can sue a family member for breach of fiduciary duty if their actions cause financial harm, trust losses, or violate the California Probate Code.
• Remedies can include removal, surcharge, compelling an accounting, or unwinding improper transactions.
• Litigation involving family members is sensitive, but necessary when your inheritance or legal rights are at risk.

In California, a fiduciary duty arises when one person is legally responsible for managing the assets, rights, or interests of another. Under the California Probate Code, fiduciaries must act with loyalty, honesty, and reasonable care.

Family members often step into fiduciary roles during emotionally charged situations, trust administration, probate, power of attorney arrangements, or conservatorship. When they accept these roles, they are bound by the same legal standards as any professional fiduciary.

At The Grossman Law Firm, we routinely represent beneficiaries harmed by a family member misbehaving in one of these roles.

A breach occurs when the fiduciary:

• Uses authority for personal benefit
• Fails to act in the beneficiary’s best interests
• Mismanages assets
• Fails to disclose important information
• Commits self-dealing
• Makes imprudent financial decisions
• Ignores trust or probate court requirements

A breach must cause financial harm or impair your rights as a beneficiary or heir.

1. Trustee of a Trust

A family member serving as trustee must comply with the trust terms, avoid self-dealing, and comply with the Probate Code.

2. Executor or Administrator of an Estate

An executor must inventory assets, pay debts, and distribute the estate correctly. Misuse of estate funds or unreasonable delay may constitute a breach.

3. Agent Under a Power of Attorney

Someone acting under a durable power of attorney must make financial decisions solely for the benefit of the principal. Misuse of authority often leads to litigation.

4. Legal Guardian

Guardians of minors or incapacitated adults must manage finances for the beneficiary’s benefit, not their own.

5. Family Partnerships or Joint Ventures

Co-owners owe duties of fair dealing and transparency. Misuse of partnership assets can support a breach claim.

Not every disagreement is a breach, but when conduct crosses into misuse of authority or financial harm, beneficiaries may need court intervention.

To win a breach of fiduciary duty case, beneficiaries generally must show:

1. A fiduciary duty existed

Trustee, executor, agent, guardian, partner, or another role recognized under California law.

2. The fiduciary breached that duty

Self-dealing, mismanagement, unreasonable delay, failure to provide an accounting, improper transfers, etc.

3. The breach caused harm

Financial losses, decreased trust value, improper distributions, or loss of inheritance rights.

4. Damages must be measurable

The court must be able to order repayment, surcharge, or other remedies.

Because these cases involve complex financial records and statutory duties, beneficiaries should seek counsel early.

Litigation against a family member is serious, but it may be unavoidable when:

• Trust assets are disappearing
• An executor refuses to provide information
• A trustee engages in self-dealing
• A power of attorney agent makes unauthorized transfers
• You suspect fraud or undue influence
• Someone is blocking your rightful inheritance

California courts enforce fiduciary obligations strictly, even when the fiduciary is a close relative. The goal is not punishment, it is restoring the assets and rights that were harmed.

Mediation may resolve some disputes, but if assets have been lost or misused, filing a probate court petition is often necessary to protect your interests.

A family member who violates their fiduciary duties may face:

Removal

The probate court can remove the trustee or executor and appoint a replacement.

Surcharge

The fiduciary can be personally liable to repay:

• Lost funds
• Improper transfers
• Diminished asset value

Repayment of Attorney’s Fees

The fiduciary may be ordered to pay fees from their own assets, not the trust.

Undoing Transactions

Courts can rescind improper transfers or restore misused property.

Court Orders Compelling Action

Including accountings, distributions, or financial disclosures.

Improper conduct can trigger these consequences, such as self-dealing, negligence, failure to invest prudently, or refusal to distribute trust assets.

• Overview of California Trust Litigation
• How to Get a Copy of the Trust?
• Beneficiary Rights in California?
• Can a Trustee Be Removed for Mishandling Assets?
• How to Get Your Trustee to Distribute Your Inheritance
• 20 Ways Your Trustee Can Be Breaching Their Fiduciary Duties
• Can’t Afford a Probate or Trust Attorney?

Can I sue my sibling for mishandling our parents’ trust?

Yes. If your sibling is acting as trustee and violates fiduciary duties, you can file a petition for breach, removal, or surcharge.

Is suing a family member different from suing a non-relative?

Legally, no. California holds all fiduciaries to the same standard, regardless of relationship.

What if I don’t have all the evidence?

Your attorney can use discovery tools, subpoenas, depositions, and document requests to uncover financial information.

Can I stop a family member from draining assets before filing a lawsuit?

Yes. You can request temporary orders, injunctions, or suspension of trustee powers.

What if the breach happened years ago?

Deadlines vary, but waiting can limit your options. Beneficiaries should act immediately if they suspect wrongdoing.

At The Grossman Law Firm, we help beneficiaries and heirs throughout California enforce their rights in probate and trust litigation.

Call (888) 443-6590 or fill out our Get Help Now form. Our Intake Specialists can evaluate your case at no cost to you. Qualifying matters will be scheduled for a Free Phone Consultation with Attorney Scott Grossman.

Originally Published November 8, 2023