Burden of Proof in a Will Contest

Tim was devastated. He’d always been close to his mother, Emily, but after she passed, he discovered a new codicil had been added to her will just weeks before her death, cutting him out entirely. He remembers vividly his mother telling him how much she valued his support over the years, yet this document completely disregarded that. He immediately hired an attorney, but learned the painful truth: contesting a will isn’t as simple as claiming it’s unfair. It requires proof, and a lot of it. Tim’s case highlights a common scenario – a late-in-life will change that feels wrong, but is legally valid unless successfully challenged. The financial stakes are enormous; Tim stood to lose over $500,000, and the legal fees were already mounting.

As an estate planning attorney and CPA with over 35 years of experience in Moreno Valley, California, I’ve seen countless will contests. What many people don’t realize is that the burden of proof rests squarely on the person challenging the will. California courts presume a will is valid if it meets basic requirements – proper signature, witnessed execution, and testamentary intent. To overturn that presumption, you must present compelling evidence supporting your claim. This is where having a CPA involved can be critical. A CPA understands the step-up in basis, capital gains implications, and the valuation of assets, which are all vital pieces of the puzzle when demonstrating the undue influence or lack of capacity.

There are several grounds for contesting a will, each with its own evidentiary requirements. Let’s break down the most common challenges and what you’ll need to prove.
First, lack of testamentary capacity is a frequent issue, especially when the testator suffered from dementia or other cognitive impairments. However, California uses a relatively low threshold for capacity. Probate Code § 6100.5 states “…California uses a relatively low threshold for capacity. A person is considered of ‘sound mind’ unless they lacked the ability to understand the nature of the testamentary act, the nature of their property, or their relationship to living family members (or suffered from a specific delusion).” This means simply being elderly or having a medical condition isn’t enough. You need medical records, testimony from doctors, and evidence of unusual behavior around the time the will was signed to demonstrate the testator genuinely didn’t understand what they were doing.

What if someone pressured the testator to change their will?

Another common challenge is undue influence, where someone coerced the testator into making changes they wouldn’t have otherwise made. This is particularly relevant when a caregiver or family member had significant control over the testator’s life. Under Probate Code § 21380, “…California law presumes undue influence if a gift is made to a care custodian of a dependent adult. The burden of proof shifts to the caregiver to prove they did not coerce the senior. If they fail, they are disinherited and often liable for attorney fees.” You’ll need to show a confidential relationship, a motive for influencing the testator, and evidence that the testator’s free will was overcome. Think financial dependence, isolation from other family members, and a sudden, unexplained change in the estate plan.

Can you contest a will just because you think it’s unfair?

Absolutely not. Standing is a fundamental requirement in any will contest. As stated in Probate Code § 48, “…you cannot contest a will just because you think it’s unfair. You must be an ‘interested person’—meaning you would financially benefit if the current will is overturned (e.g., a child disinherited by a new will, or a beneficiary named in a previous version).” Disappointed heirs with no financial stake have no legal right to challenge the document. This is also where distinguishing between Execution Fraud (forged signature) and Inducement Fraud (lying to the testator) is critical. “…proving a signature is fake often requires a forensic handwriting expert, whereas proving fraud in the inducement requires evidence that the testator relied on a lie (e.g., ‘your son is stealing from you’) to change their estate plan.” Forging a signature is a criminal act and requires expert testimony, while proving fraud demands evidence of intentional deception.

What happens after the will is admitted to probate?

Finally, even if you have a strong case, time is of the essence. Once the will is admitted to probate, interested parties have a strict 120-day window to file a petition to revoke probate. Probate Code § 8270 states “…once the will is admitted to probate, interested parties have a strict 120-day window to file a petition to revoke probate. If you miss this deadline, the will is generally locked in stone, even if it was forged or signed under duress.” Don’t delay seeking legal counsel and gathering evidence. Waiting too long can permanently forfeit your right to challenge the will.

How do enforcement rules in California probate court shape outcomes for heirs and fiduciaries?

The path through California probate is rarely a straight line; it requires precise adherence to statutory deadlines, accurate asset characterization, and strict fiduciary compliance. Without a clear roadmap, what begins as a standard administrative proceeding can quickly dissolve into a costly battle over interpretation, valuation, and beneficiary rights.

California probate is most manageable when authority is documented early, assets are classified correctly, and procedure is followed consistently from petition through closing. When the process is approached with realistic expectations about notice, claims, accounting, and dispute risk, the estate is more likely to move toward closure without avoidable conflict or delay.

Verified Authority on California Will Contests

• The 120-Day Statute of Limitations: California Probate Code § 8270
  Time is the enemy in a will contest. Under Section 8270, an interested person may petition the court to revoke the probate of a will, but this petition MUST be filed within 120 days after the will is admitted. Missing this deadline is usually fatal to the case.
• Mental Competency Standard: California Probate Code § 6100.5 (Unsound Mind)
  This statute defines exactly what “mental incompetency” means in probate. It is not just general forgetfulness; the contestant must prove the deceased did not understand the nature of the testamentary act, could not recollect their property, or was suffering from a specific hallucination or delusion that dictated the will’s terms.
• Presumption of Undue Influence (Caregivers): California Probate Code § 21380
  To protect vulnerable seniors, California law automatically presumes undue influence if a will leaves assets to a paid care custodian or the lawyer who drafted the instrument. This shifts the heavy burden of proof onto the accused to prove their innocence.
• No-Contest Clause Enforceability: California Probate Code § 21311
  Many wills contain threats to disinherit anyone who challenges them. This statute limits the power of those clauses. A beneficiary cannot be penalized for a contest if the court finds they had “probable cause” to file the lawsuit.
• Standing to Contest: California Probate Code § 48 (Interested Person)
  Not everyone can sue. To contest a will, you must qualify as an “interested person”—typically an heir who would inherit under intestate succession (if there were no will) or a beneficiary named in a prior valid will.
• Financial Elder Abuse Remedies: California Probate Code § 859 (Double Damages)
  Will contests often overlap with elder abuse claims. If the court finds that a person used undue influence, fraud, or bad faith to take assets (or change a will) to the detriment of the estate, they can be liable for twice the value of the property taken, plus attorney fees.