What Happens If the Will is Invalid

It started with a phone call from Emily, absolutely distraught. Her mother, Margaret, had recently passed away, but Emily discovered a codicil – a formal amendment to the original will – that completely disinherited her. Emily had been Margaret’s primary caregiver for years, and the codicil, signed just weeks before Margaret’s death, left everything to a new “friend” Margaret had met at a senior center. Emily suspected foul play; Margaret had been increasingly confused and easily influenced, and the friend seemed to have isolated her from the family. The cost of challenging this codicil? Potentially tens of thousands in legal fees, and the emotional toll of fighting over her own mother’s legacy.

Unfortunately, Emily’s situation isn’t uncommon. Wills are frequently contested, and often the central question isn’t whether Margaret wanted to disinherit Emily, but whether the codicil itself is legally valid. A poorly executed or improperly reasoned will, or even a codicil, can be deemed invalid by the probate court, leading to a very different outcome than Margaret intended.

What are the Common Grounds for Challenging a Will?

Several factors can invalidate a will in California. The most frequent challenges fall into a few key categories: improper execution, lack of testamentary capacity, undue influence, fraud, and standing. Each carries a different burden of proof and requires specific evidence.

What Constitutes “Improper Execution?”

California law has very specific requirements for how a will must be signed and witnessed. Generally, the testator (the person making the will) must sign the document in front of two disinterested witnesses, who must also sign the will acknowledging they saw the testator sign. If these formalities aren’t followed exactly, the will can be invalidated. Even a slight deviation—say, a witness signing after the testator, or the witnesses not being present at the same time—can be fatal. This is a surprisingly common error, as many people attempt “DIY” wills or use outdated forms that don’t comply with current law.

What if the Testator Didn’t Have Mental Capacity?

A will is only valid if the testator possessed “testamentary capacity” at the time of signing. This doesn’t mean they needed to be perfectly lucid, but they did need to understand the nature of the act—that they were creating a document that would distribute their property after death—understand the nature of their property, and understand their relationship to their living family members. Probate Code § 6100.5 provides that 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 can be a complex area, particularly in cases involving dementia or Alzheimer’s disease, requiring medical records review and potentially testimony from the treating physician.

Can a Caregiver Unduly Influence a Testator?

This is another frequent battleground. If a caregiver exerted such control over the testator that the will reflects their wishes rather than the testator’s, the will can be invalidated for undue influence. Probate Code § 21380 states that 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. Evidence of isolation from family, changes in the testator’s routine, and financial benefits accruing to the caregiver are all red flags.

What About Forgery or Fraud?

If someone outright forged the testator’s signature, or tricked them into signing a document they didn’t understand, the will is invalid. However, proving forgery or fraud can be challenging. There’s a crucial distinction between Execution Fraud (forged signature) and Inducement Fraud (lying to the testator): 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.

Who Can Even Contest a Will in the First Place?

Not everyone has the right to challenge a will. You must have “standing,” meaning you’re 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). Probate Code § 48 clarifies this point. A distant cousin, for example, likely wouldn’t have standing unless they could demonstrate a direct financial loss.

What Happens if a Contest is Successful?

If the court determines the will is invalid, it will typically be “set aside,” meaning it’s no longer enforceable. The estate will then be distributed according to either a prior valid will, or if no prior will exists, under California’s intestate succession laws—which dictate how property is distributed based on family relationships.

As an estate planning attorney and CPA with over 35 years of experience, I’ve seen countless will contests. A key advantage of having a CPA involved is understanding the tax implications of these challenges. A successful contest can dramatically alter the step-up in basis—the value used to calculate capital gains taxes—and significantly impact the estate’s overall tax liability. That’s why a thorough estate plan isn’t just about who gets what, but how they get it, minimizing taxes and maximizing the benefit for your loved ones.

What determines whether a California probate estate closes smoothly or turns into litigation?

California probate is designed to provide court-supervised transfer of property, yet cases often break down when authority is unclear, required steps are missed, or disputes arise over assets, notice, and fiduciary conduct. When the process is misunderstood, families can face avoidable delay, escalating conflict, and increased exposure to creditor issues, hearings, or litigation before the estate can close.

• Escalation: Prepare for probate litigation if agreement fails.
• Document Challenges: Understand the grounds for contesting a will.
• Trust Issues: Navigate complex trust litigation in probate.

Ultimately, the difference between a routine distribution and a protracted legal battle often comes down to preparation. By anticipating the demands of the Probate Code and addressing potential friction points with beneficiaries and creditors upfront, fiduciaries can navigate the system with greater confidence and lower liability.

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.