What is a codicil for a will, and when should you use one?

A short note before you start

This guide is general information for the United States, not legal, tax, financial or medical advice. Whether a codicil is valid, and exactly what it must say, depends on the state where you live. Confirm current rules with your state's probate court self-help site or an estate planning attorney before you sign anything.

What is a codicil for a will?

A codicil for a will is a short, separate legal document that changes, adds to or cancels one or more provisions in a will that already exists, while leaving the rest of the will in force. Nolo describes a codicil as a document that explains, modifies, adds to, subtracts from, qualifies, alters or revokes provisions already in a will¹. Think of it as a written amendment clipped to the original, not a replacement for it. For definitions of related terms like "testator" and "probate," see the estate planning glossary.

People use a codicil for small, specific changes: swapping an executor, adjusting one gift, adding a grandchild born after the will was signed, or removing a bequest to someone no longer in the picture. It is not meant for a rewrite. If more than a change or two is needed, most guidance points toward a new will instead of stacking codicils².

Codicil to a will vs. codicil of a will vs. codicil in a will

These are the same document described with different prepositions. A "codicil to a will," a "codicil of a will" and a change made "in a will" all mean the same thing: an amendment attached to and read together with the original will. There is no legal distinction between the phrases.

How is a codicil different from a new will?

The core difference is scope and effect. A codicil edits specific provisions and leaves everything else standing; a new will typically states that it revokes all earlier wills and codicils, replacing the document entirely.

A codicil that is properly signed and witnessed also "republishes" the will it amends in the eyes of the law, meaning the will is treated as re-executed as of the codicil's date¹. That is one more reason to keep codicils simple and few.

What are the legal requirements for a valid codicil?

A codicil is only valid if it is executed the same way the underlying will had to be executed. That means, in nearly every state, the document must be in writing, signed by the person making it, and signed by witnesses who watch the signing or hear it acknowledged.

Signing and witnesses

Nearly all states require two witnesses who do not stand to inherit anything under the will or codicil. AllLaw notes that "almost all states require two disinterested" witnesses, and that a beneficiary who witnesses the document risks having their own gift declared void by the probate court, even though the rest of the document stays valid⁶. Two states, Colorado and North Dakota, allow a notarized signature in place of witnesses⁶.

State statutes spell out the details. California requires the codicil, like a will, to be signed in front of at least two people present at the same time, who understand they are witnessing a will⁴. Texas requires at least two credible witnesses age 14 or older who sign in the testator's presence, though a codicil written entirely in the testator's own handwriting can skip witnesses in states that allow holographic documents⁵. See our holographic will guide for which states allow a handwritten, unwitnessed document and which do not; the same state-by-state split generally applies to a handwritten codicil.

Self-proving affidavits

A self-proving affidavit is a sworn, notarized statement attached to the codicil in which the witnesses confirm what they saw. It lets a probate court accept the codicil later without locating the original witnesses to testify⁷. Most states allow this option, but the District of Columbia and Ohio do not⁶.

What a codicil must say

A codicil should identify the will it amends by date, state exactly what is changing, and confirm that every other provision of the original will stays in effect. Do not cross out or write directly on the original will; that raises questions about tampering and is not a valid way to make a change in most states.

How much does a codicil cost?

An attorney-drafted codicil generally costs $100 to $400, with attorneys typically billing $200 to $500 an hour for the work depending on experience, location and how complicated the change is⁸. A new will, by comparison, starts at roughly $300 and climbs from there with the complexity of the estate⁸. Some services offer free or low-cost templates to fill in yourself, though a self-prepared codicil still has to meet your state's signing and witnessing rules to hold up in probate.

The math shifts once you have made more than one codicil. Multiple codicils layered on top of one will, and on top of each other, create more paperwork for your executor to read together and more chances for language to conflict. At that point, many attorneys recommend simply paying for a new will that consolidates everything into one clean document².

How does this vary by state?

Wills and codicils are governed by state law, not federal law, so the exact witness count, notarization options and handwriting rules differ by state. California and Texas, shown above, both require two witnesses but differ on minimum witness age and on what a handwritten codicil needs. Colorado and North Dakota permit notarization instead of witnesses; the District of Columbia and Ohio do not allow a self-proving affidavit at all⁶. Before you sign a codicil, check your state's probate court self-help site for its current witness, notarization and holographic-document rules; our probate courts by state guide links to each one.

Step-by-step: how to write and execute a codicil

1. Find your original, signed will and read it in full before deciding what to change.
2. Write the codicil as a separate document. Identify the will by its date and state clearly which section or provision you are changing, adding or revoking.
3. Include a sentence confirming that every other part of the original will remains in full force.
4. Date and sign the codicil yourself, the same way you signed the original will.
5. Sign in front of at least two witnesses who are not beneficiaries of the will or codicil, present at the same time, who then sign it themselves. Confirm your state's exact witness rules first.
6. Consider a notarized self-proving affidavit attached to the codicil, if your state allows one, so witnesses do not need to be found later.
7. Store the codicil with the original will, not separately, so anyone who finds one finds both.
8. Tell your executor, or whoever holds a copy of your family guide, that a codicil exists and where it is kept.

What should you record in your family guide about a codicil?

A codicil is easy to lose track of because it is a second document that has to travel with the first one. Record, in plain language, that a codicil exists, the date it was signed, what it changed, and exactly where the original will and codicil are stored together, whether that is a fireproof box, a safe deposit box or an attorney's office. If you update or revoke a codicil later, note that too, with the date.

This is the kind of detail a family guide, such as the one Omliva helps families build, keeps current so an executor is not left guessing whether a codicil they found is the most recent version. See your guide for how that works.

What mistakes do people commonly make with codicils?

• Writing directly on the original will, crossing out lines or adding notes in the margin, instead of preparing a separate signed and witnessed document.
• Using a beneficiary, or a beneficiary's spouse, as a witness, which can void that person's gift in most states⁶.
• Failing to identify the original will by date, leaving it unclear which will the codicil amends.
• Stacking several codicils over the years until the combined document is contradictory or hard to read, instead of switching to a new will.
• Storing the codicil apart from the original will, or never telling the executor it exists, so it is never found.
• Skipping witnesses or notarization because the change feels minor. A codicil always needs the same formality as a will.

When to get professional help

A codicil for a single, simple change, such as updating an executor's name or address, is often something people handle with a template and careful attention to their state's witness rules. Bring in an estate planning attorney when you are making more than one or two changes, disinheriting someone, changing how real estate or a business passes, updating provisions for a minor or a beneficiary with a disability, or when a family member is likely to contest the outcome.