What Makes a Codicil Invalid

Emily just called, frantic. Her mother passed away last month, and Emily was certain her mother had updated her will with a signed codicil leaving Emily a specific antique necklace. But the attorney handling probate says the codicil isn’t valid, and the necklace will go to Emily’s aunt. The cost? Not just the sentimental value of the necklace, but potentially a family rift—and now, legal fees to contest the probate. This is far too common, and preventable with a little foresight.

A codicil, as most clients understand, is simply an amendment to an existing will. It doesn’t require a complete rewrite, but it must adhere to the same strict requirements as the original will to be legally enforceable. The most frequent issues arise from improper execution, conflicting language, or simply a failure to meet the technical standards California law demands.

What Errors Can Void a Codicil?

The most common reason a codicil is deemed invalid is a flaw in its execution. California law, under Probate Code 6110, dictates specific requirements. Your codicil must be signed by the testator—the person making the changes—or by someone signing on their behalf and under their direction, in their presence. Crucially, it must be witnessed by at least two adults who understand they are witnessing the signing of a codicil to a will. These witnesses must also sign the document in the testator’s presence and in the presence of each other. A missing signature, an improperly dated document, or witnesses who didn’t observe the signing can all lead to invalidation.

A seemingly minor oversight, like a witness failing to sign immediately after witnessing the signature, can be grounds for a challenge. Similarly, if the testator lacks the mental capacity to understand they are signing a codicil – due to dementia, medication, or other cognitive impairment – the codicil is vulnerable. Establishing testamentary capacity is always key, and any ambiguity will be scrutinized by the court.

• Witness Qualifications: Witnesses must be disinterested – meaning they don’t stand to benefit from the codicil’s provisions.
• Testator Capacity: The person signing the codicil must understand the nature of the document and its effect.
• Proper Attestation: Witnesses must attest to the signing in the testator’s presence and in the presence of each other.

What Happens if a Codicil Conflicts with the Original Will?

Another common problem arises when the codicil contains language that directly contradicts the original will. While a codicil is intended to modify, not obliterate, the original document, a clear conflict creates ambiguity. Courts will generally prioritize the most recent, unambiguous language. However, if the conflict is significant and makes the overall testamentary intent unclear, the entire will – including the codicil – could be invalidated. For example, if the original will leaves everything to children equally, and a codicil leaves a specific asset to a third party without altering the equal division of the rest of the estate, that’s likely valid. But if the codicil attempts to rewrite the entire distribution scheme without clearly revoking the original provisions, it’s a recipe for litigation.

If a codicil is invalidated, assets may force full probate; however, for deaths on or after April 1, 2025, estates under $208,850 (per CPC § 13100) may still qualify for simplified procedures. This limit is set until 2028.

What About Handwritten Codicils?

California is one of the few states that recognizes holographic codicils – those entirely handwritten by the testator. However, these codicils are subject to especially rigorous scrutiny. As outlined in CPC 6111, handwritten codicils are valid in California under Probate Code 6111, but only if the signature and material provisions (who gets what) are in your own handwriting. No witnesses or notary are required for this specific format. However, even a small portion typed or pre-printed can invalidate the entire codicil. The handwriting must be clear and unambiguous, demonstrating the testator’s intent to change their estate plan.

Digital Assets and the Need for Modern Codicils

Today, many assets exist only in digital form—cryptocurrency, online accounts, and digital photographs. A standard codicil often fails to include the specific RUFADAA language (CPC § 870) required to bypass federal privacy laws, potentially leaving your heirs locked out of crypto-wallets and email accounts. It’s crucial to explicitly authorize access to these digital assets within the codicil.

As an attorney and CPA with over 35 years of experience, I’ve seen firsthand the heartache and expense caused by poorly drafted or improperly executed codicils. My CPA background is particularly valuable here. We can ensure any changes to your estate plan account for potential step-up in basis benefits, minimizing capital gains taxes for your heirs, and accurately valuing assets subject to estate tax. We don’t just draft documents; we build a comprehensive strategy to protect your family and preserve your legacy.

• Digital Access: Specifically address access to digital assets and online accounts.
• Tax Implications: Consider the tax consequences of any changes made by the codicil, especially regarding asset valuation.
• Regular Review: Review your codicil – and your entire estate plan – every three to five years, or whenever there’s a significant life event.

What About LLCs and Business Ownership?

If you’ve made changes to your business structure or ownership of an LLC, your codicil must reflect those changes. As of March 2025, FinCEN has exempted domestic U.S. LLCs from BOI reporting; however, foreign-registered entities in the U.S. still face mandatory filing requirements and potential penalties. Failing to update your estate plan to reflect these changes can lead to complications in transferring business ownership and maintaining compliance.

Finally, remember that the 2026 ‘tax cliff’ was averted by the OBBBA, which permanently increased the Federal Estate Tax Exemption to $15 million per person effective Jan 1, 2026. Old formula clauses should be reviewed to ensure they don’t over-fund trusts under these new limits.

How do California courts decide whether a will reflects true intent or creates ambiguity?

In California, a last will and testament is reviewed under probate standards that focus on intent, capacity, and execution. Clear drafting reduces ambiguity, limits misinterpretation, and helps families avoid unnecessary conflict during estate administration.

• Planning: Review estate planning regularly.
• Law: Check legal requirements.
• People: Update testator details.

When a will is drafted with California probate review in mind, it becomes a stabilizing roadmap rather than a source of conflict. Clear intent, proper authority, and compliant execution protect both families and estates.

Primary Legal Authorities Governing Probate and Estate Administration

• Probate & Local Court Rules:
  
  Riverside Superior Court – Probate Division
  
  Official Riverside County probate rules (Title 7), filing procedures, examiner notes, and specific protocols for remote appearances via the court’s designated platform for non-evidentiary hearings.
• Attorney Licensing & Ethical Standards:
  
  State Bar of California
  
  The authoritative source to verify attorney license status, disciplinary history, and current ethical rules governing California attorneys and client trust accounts (IOLTA).
• Judicial Council Forms & Self-Help:
  
  California Courts – Wills, Estates, and Probate
  
  State-issued probate forms and guidance, including small estate procedures ($208,850 limit), primary residence transfers under AB 2016 ($750,000 limit), and executor responsibilities.
• Federal Estate & Gift Tax Law:
  
  IRS Estate Tax Guidelines
  
  Federal rules governing estate and gift tax filing, including the permanent 2026 exemption of $15 million per individual (indexed for inflation).