When a parent dies and the will reads nothing like what they always said it would, the family's first reaction is usually disbelief. The second is anger. The third, sometimes weeks later, is a quiet phone call to a probate attorney that begins with the words, can we challenge this. The answer in California is yes, but only on specific legal grounds, only within a tight time window, and only with the kind of evidence that holds up in a probate courtroom. This article walks through the five recognized grounds, the deadlines, the no-contest clause analysis, and the harder question that often matters more than the law: when is the fight worth fighting.
What a Will Contest Actually Is, and What It Isn't
A will contest is a formal legal proceeding asking the probate court to declare a will (or a specific amendment, called a codicil) invalid. If the court agrees, the will is set aside, and the estate is distributed under the prior valid will, or, if none exists, under California's intestate succession rules. A will contest is not a way to renegotiate the terms of a valid will. It is not a remedy for a will that is unfair, unequal, or surprising. People are generally free to leave their property to whomever they wish. The contest mechanism exists for a narrower problem: a will that does not reflect what the person actually decided, because something went wrong at the moment the will was created or signed.
Ground 1: Lack of Testamentary Capacity
To make a valid will in California, the testator must have testamentary capacity at the time of execution. The standard is set out in Probate Code section 6100.5 and is lower than the standard for executing a contract or living trust. The testator must understand the nature of the act, the nature and extent of their property, and the natural objects of their bounty (typically spouse, children, and close relatives). They must also be free of a delusion or hallucination that materially affects the disposition.
Capacity contests usually rise or fall on medical evidence. Hospital charts, treating physician notes, neurological evaluations, and the testimony of caregivers who saw the testator in the weeks before signing carry weight. A dementia diagnosis alone does not defeat a will, because capacity can fluctuate. The question is whether the testator had a lucid interval at the moment of signing. A diagnosis combined with rapid decline, missed names of children, and inability to identify familiar property is the pattern that wins.
Ground 2: Undue Influence and the PC 21380 Presumption
Undue influence is the most commonly successful ground in California will contests, and the one where state law gives challengers the most help. Welfare and Institutions Code section 15610.70 defines undue influence as excessive persuasion that causes another person to act or refrain from acting by overcoming that person's free will and results in inequity. The court considers the vulnerability of the victim, the influencer's apparent authority and tactics, and the equity of the result.
The decisive tool is Probate Code section 21380, which creates a presumption of fraud or undue influence for donative transfers to:
- The person who drafted the will or trust.
- A care custodian who provided services to a dependent adult within the 90 days before or after the document was signed.
- Cohabitants and employees of the drafter or care custodian.
- Certain fiduciaries and the spouse, registered domestic partner, or relatives of the drafter.
Once the presumption applies, the burden shifts to the recipient to rebut it by clear and convincing evidence, typically by producing an independent attorney review certificate. Many caregivers and drafters cannot meet that burden. That is why the PC 21380 presumption is often the strongest ground in cases involving last-minute changes that benefit a paid caregiver, a new spouse who appeared months before death, or the attorney's own family member.
Ground 3: Fraud
Fraud as a ground for will contest comes in two flavors. Fraud in the execution means the testator was tricked about the nature of the document being signed (told it was a deed when it was a will, for example). Fraud in the inducement means the testator was deceived about material facts that caused them to write the will the way they did (told that a child was dead when they were alive, or that a child had stolen from them when they had not).
Fraud requires proof of a knowing misrepresentation, made with intent to deceive, that was reasonably relied upon by the testator and caused the disposition. It is harder to prove than undue influence, because it requires evidence of a specific lie. When the evidence supports it, however, it is one of the most powerful grounds, because fraud also exposes the wrongdoer to disinheritance under Probate Code section 259 (the slayer-and-elder-abuser disinheritance statute).
Ground 4: Improper Execution
California requires three things for a will (other than a holographic, or handwritten, will) to be properly executed: the testator's signature, witnessed by at least two persons present at the same time, who both understand the document is the testator's will and who both sign during the testator's lifetime. Probate Code section 6110 spells out the formalities, and Probate Code section 6110(c)(2) provides a harmless-error rule that can sometimes save a defectively executed will if the proponent shows by clear and convincing evidence that the testator intended the document to be a will.
Improper-execution contests usually arise with online wills downloaded and signed without witnesses, wills signed in a hospital room with only one witness, wills signed by witnesses on different days, and wills signed by interested witnesses (who, while not invalid as a class, trigger a presumption that the gift to them was procured by duress, menace, fraud, or undue influence under Probate Code section 6112).
Ground 5: Revocation
A will can be revoked in three ways: by a later will or codicil that expressly or by implication revokes the prior one, by a physical act of revocation (burning, tearing, canceling, obliterating, or destroying the will with intent to revoke), or by operation of law (for example, the dissolution of marriage revokes provisions in favor of a former spouse). When a more recent valid will surfaces after the proponent has filed an older one, the newer document controls. When the testator was last seen with the will and it is missing at death, California law presumes the testator destroyed it with intent to revoke. Both situations are revocation contests.
The 120-Day Clock You Cannot Miss
Probate Code section 8270 sets the standard deadline for filing a will contest in California. A petition to revoke probate of a will must be filed within 120 days after the will is admitted to probate. There are limited extensions for parties who were not served with notice and for certain after-discovered evidence, but they are narrow and unreliable. The practical rule: if you are an heir or beneficiary, calendar the 120 days the moment you receive a Notice of Petition to Administer Estate. Bring the will and all surrounding documents to an attorney long before the deadline. Cases lost on the clock are the saddest cases we see.
What No-Contest Clauses Actually Do Under PC 21311
Many California wills and trusts include a no-contest clause that purports to disinherit anyone who challenges the document. Decades ago, these clauses were ferocious. Today, Probate Code section 21311 has narrowed them significantly. A no-contest clause is enforceable only against three categories of pleadings: a direct contest brought without probable cause, a pleading challenging the transferor's ownership of property, and a creditor's claim or prosecution of an action based on it. The decisive concept is probable cause: a direct contest brought with probable cause does not trigger forfeiture.
Probable cause exists when, at the time of filing, the facts known would cause a reasonable person to believe there is a reasonable likelihood that the requested relief will be granted after an opportunity for further investigation or discovery. The standard is not high, but it is real. Before any contest is filed, the analysis needs to be done in writing, the supporting evidence needs to be in hand, and the strength of the underlying claim needs to be candidly assessed. That is the work that protects the client.
When Contesting Is Worth It, and When It Isn't
Even when a contest has merit, the harder question is whether to file. We weigh the same factors with every client:
- Value at stake. A contest that recovers a $100,000 share is a different decision than a contest that recovers a $3 million share. The arithmetic of attorney fees, time, and family cost matters.
- Strength of evidence. Is there a treating physician who will testify about capacity. Is there a PC 21380 presumption available. Are there contemporaneous emails or texts showing the influence. Or is the case built on suspicion alone.
- The opposing party. A wealthy, well-counseled influencer can drag a contest out for years. A self-represented sibling holding the original will may fold at mediation. The opposition matters as much as the merits.
- Family cost. Some clients want vindication regardless of price. Others would settle for less to avoid burning the family down. Both decisions are legitimate. They are not the lawyer's decision to make.
- Statute of limitations. A 120-day window forces decisions that, with more time, might be more careful. We tell every client what the deadline does to leverage.
Most contested matters resolve at mediation, often with a settlement that distributes assets in proportions the family can live with. The minority that go to trial usually involve a serious imbalance between the parties on willingness to fight or evidence on the table. When a contest is right, the law in California is fair and the tools are real. When it is not right, the most useful thing a probate attorney can do is say so, clearly, in the first meeting. For a deeper look at how contested matters are litigated in our office, see our Probate Litigation page, and for the underlying probate administration process, see our Probate overview.
This article is for informational purposes only and does not constitute legal advice. Will contests turn on the specific facts, documents, and timelines of each case. Contact MVP Law Group for a free, confidential consultation if you suspect a California will or trust does not reflect the true wishes of the person who made it.