Michigan Codicil vs. New Will: Which to Use (and Why 90% of the Time It's a New Will)

You need to change one line in your will. You do NOT want to redo the whole thing. So you ask around and someone mentions a "codicil" -- a short amendment to a will that sounds cheaper and easier than starting over. In Michigan the codicil is a real legal instrument, but it comes with a surprise: it has to be signed and witnessed exactly like a new will. The formal effort is nearly identical. Once you understand that, the choice between a codicil and a new will becomes obvious in most cases -- and about 90% of the time the answer is "new will." This guide explains exactly why, what a Michigan codicil looks like, when a codicil still makes sense, and the "republication doctrine" that can quietly undo your intent if you get the sequencing wrong.

The 30-Second Answer

Use a codicil ONLY if all of these are true: (1) you have exactly one small change to make, (2) the change is administrative (address correction, executor swap, small dollar amount change), (3) your existing will is under 5 years old, (4) you have no existing codicils, and (5) the change does not affect who gets what. If ANY of those five is false, do a new will instead. A new will lets you say "I hereby revoke all prior wills and codicils" and start clean.

Both take the same effort to execute correctly. Both require your signature, two witnesses signing at the same time, and (recommended) a self-proving notary block under MCL 700.2504. The cost difference is minimal. The clarity difference is enormous.

What a Codicil Actually Is

A codicil is a formal supplementary document that amends an existing will. It does not replace the will -- it modifies it. The original will and the codicil are read together at probate. Multiple codicils can technically stack on the same will, but Michigan probate attorneys almost universally advise against stacking more than one.

Typical Michigan codicil uses in practice:

• Change the named personal representative (executor) because your first choice died, resigned, or you had a falling out
• Add or update a specific dollar bequest -- "the $5,000 to my niece is increased to $7,500"
• Remove a specific bequest because the beneficiary died or the item no longer exists
• Correct a typographical error in a name, date, or address
• Add a small charitable bequest

Notice what codicils are NOT typically used for: changing residuary beneficiaries, restructuring the entire distribution, changing guardians for minor children, or adjusting substantial percentages. Those changes deserve a new will.

Codicils Require the SAME Formalities as Wills

This is the fact that surprises Michigan DIYers most. Under Michigan's Estates and Protected Individuals Code, codicils are treated legally identically to wills for execution purposes. Per the Kent County guide to Michigan will types and MCL 700.2502, a valid Michigan codicil must be:

• In writing. Verbal codicils are not valid in Michigan.
• Signed by the testator (or by another individual in the testator's conscious presence and by the testator's direction).
• Signed by two witnesses within a reasonable time after each witness sees the testator sign OR sees the testator acknowledge the signature.

Alternative execution paths:

• Holographic codicil (MCL 700.2502(2)): If the codicil is dated, the material portions are in the testator's handwriting, and the testator's signature appears, no witnesses are required. This is a rare and risky path -- courts have thrown out holographic amendments that were unclear about testamentary intent (see the Windham and Smoke cases in our Michigan will revocation guide).
• Self-proved codicil (MCL 700.2504): The testator and both witnesses sign a sworn statement before a notary. This creates a "conclusive presumption" of proper execution and eliminates the need for witnesses to testify at probate. Almost every Michigan practitioner recommends this option.

Bottom line: a codicil is not "easier" than a will in the execution sense. It is legally identical in formality burden. What makes a codicil shorter is the drafting -- but the signing ceremony is the same.

When a Codicil Actually Makes Sense

Given identical formalities, when is a codicil the right tool? Really only when both of these are true:

1. You have exactly one small, discrete change to a will you drafted recently and are confident is otherwise correct.
2. You do not want to disturb other provisions of the will because they still reflect your intent perfectly.

Example: Your will names your brother John Smith as personal representative. John moved to Australia and does not want the job. Your backup is your sister Mary. A one-paragraph codicil that says "I hereby delete Article VII and substitute the following: I appoint MARY SMITH as my personal representative, and if she is unable or unwilling to serve, I appoint my nephew ROBERT SMITH." Sign, notarize, done. The rest of the will is untouched.

If instead the executor change also requires you to reconsider who inherits the family cottage, whether your kids need staggered distributions, and whether the outdated tax provisions from 2015 are still sensible -- that is a new will.

When You Need a New Will Instead

Draft a new will (with an express revocation clause) whenever ANY of these apply:

• You already have one or more codicils. Do NOT stack. Restart clean.
• Your existing will is 5+ years old. Tax law, family circumstances, and asset composition have all moved. A codicil papering over an outdated will invites litigation.
• You have multiple changes. Even if each change is small, three separate codicils on a single will is a probate nightmare. Once you count more than one change, do a new will.
• The change affects beneficiaries, percentages, or the residuary clause. These are substantive changes that deserve a full fresh document.
• You have had a major life event. Marriage, divorce, birth of a child, death of a beneficiary, moving between states, buying/selling substantial property -- these all trigger a new will.
• The old will has any drafting errors, ambiguity, or outdated legal language. Codicils cannot cure a defective will. If the original had problems, the codicil inherits them.
• You want the change to be private. A codicil references and identifies the original will (including the date) in a way that makes the whole update chain visible on probate. A new will with a revocation clause simply supersedes.

The rule of thumb we teach: if you are asking "codicil or new will?", the answer is almost always new will. The exception is a single administrative fix to a recent, clean, uncontested will.

The Republication Trap Nobody Warns You About

Here is the doctrine that trips up more DIY codicil users than any other single thing: a validly executed codicil republishes the underlying will as of the codicil's date. In practical terms, the law treats the original will as if it had been signed on the day you signed the codicil.

Why does this matter? Two scenarios:

Scenario 1: The Interested-Witness Save

Suppose your original 2015 will was witnessed by your daughter Sarah, who is also a substantial beneficiary. Under Michigan's "interested witness" rules (MCL 700.2505), her being a witness does not invalidate the will, but a challenger could argue it. If you sign a codicil in 2026 witnessed by two disinterested people, the codicil republishes the whole will as of 2026 with the new (clean) witnesses. Sarah's earlier attestation is effectively cured.

Scenario 2: The Unintended Republication

Suppose your 2015 will made a bequest "to the wife of my brother John." At the time, John was married to Susan. In 2020 they divorced. In 2023 John remarried to Karen. If in 2026 you sign a codicil (about something else entirely) and it republishes the will, courts may now interpret "the wife of my brother John" as referring to Karen -- because the will is treated as executed in 2026. If you wanted the money to go to Susan, you have accidentally cut her out. Republication can rewire beneficiary language you never intended to change.

Per the WEL Partners analysis of the republication doctrine, courts routinely treat the original will "as though it were executed on the date of the republication event, which is typically the date of the codicil." The upshot: every codicil is a subtle rewrite of the original will's temporal frame, and you have to think through the implications for every beneficiary described by relationship rather than by name.

For most simple codicils (adding a specific dollar bequest, changing an executor by name), republication is harmless. For codicils involving relational language ("my spouse," "the children of my brother," "my current employer's retirement plan"), republication can silently change who inherits.

Sample Michigan Codicil (Copy-and-Paste Structure)

If you have decided a codicil is right for your situation, here is the skeleton Michigan attorneys use. Adapt to your specific change:

That structure is fully compliant with MCL 700.2502 (execution) and MCL 700.2504 (self-proving affidavit). Two witnesses, notary, republication clause. Total drafting time: 15 minutes. Total signing time: another 30 minutes at a bank or UPS Store notary.

The Safe DIY Playbook

1. Ask yourself the 5-question test (from the 30-second answer). If any answer is "no," draft a new will instead.
2. Locate your original will and read it end-to-end. Identify by article and paragraph number the exact provision you want to change.
3. Draft the codicil using the structure above, referencing the will by exact title and date. Include only the one change plus the "everything else is confirmed" ratification clause.
4. Recruit two disinterested witnesses. They cannot be beneficiaries under the will or the codicil. Common choices: neighbors, coworkers, adult non-family friends.
5. Schedule a notary appointment. Bank branches (free if you have an account), UPS Stores, AAA offices, Michigan Secretary of State locations, and mobile notaries all work. Bring both witnesses.
6. Execute together. You sign first, then both witnesses sign in your presence and in each other's presence, then the notary acknowledges all three signatures.
7. Physically attach the codicil to the original will. Do NOT put them in separate places. The successor probate will need both together.
8. Notify your named personal representative. Give them a copy or at least tell them a codicil now exists.
9. Update the location record. If you deposited the original will with the probate court under MCL 600.880c, file the codicil there too.

Frequently Asked Questions

Does a Michigan codicil have to be notarized?

No, but strongly recommended. A codicil is validly executed with just the testator's signature and two witnesses' signatures. Adding a notary block turns it into a "self-proved" codicil under MCL 700.2504, which creates a conclusive presumption of proper execution at probate and eliminates the need to track down witnesses years later.

Can a beneficiary of my will witness my codicil?

Michigan does not invalidate a will or codicil signed by an interested witness (MCL 700.2505), but it invites challenges. Always use disinterested witnesses -- adults who receive nothing under the will or codicil.

Do I have to attach the codicil to the original will?

Not legally required, but strongly recommended. Michigan courts want to see the entire will-plus-codicil chain when the will is offered for probate. Physically attaching (stapling or storing in the same envelope) reduces the risk of the codicil being lost.

Can I revoke a codicil later?

Yes, using the same methods as revoking a will -- a subsequent codicil or new will that explicitly revokes it, or a physical act of destruction with intent. See our Michigan will revocation guide for the mechanics.

If I revoke my codicil, does the original will provision come back?

Generally yes if the codicil was silent about revoking the underlying provision, and generally no if the codicil expressly deleted the provision. This is the "revival" doctrine and it gets complicated fast. When in doubt, do a new will that unambiguously states what you want.

How many codicils can I have on one will?

Legally, any number. Practically, one. Michigan probate attorneys advise that once you feel the need for a second codicil, replace the whole will instead. Stacked codicils are the most common source of will-contest litigation.

Do I need to re-notarize my will when I add a codicil?

No. The original will's self-proving affidavit (if it had one) remains valid. The codicil should have its own self-proving affidavit. At probate the two are read together.

Can a codicil fix a defective will?

Sometimes but rarely. If the underlying will has execution defects (missing witness signatures, wrong number of pages, etc.), a subsequent codicil that "republishes" the will can potentially cure some defects. This is complicated and unreliable -- do not count on it. If the original will has known execution defects, do a fresh new will.

Is a codicil cheaper than a new will if I hire an attorney?

Not by much. Most Michigan attorneys charge $200-$500 for a single-provision codicil versus $500-$1,500 for a simple new will. If you are doing it yourself with a template, the cost difference collapses -- a codicil takes 15 minutes to draft, a full new will takes an hour. The savings do not justify the risk of ambiguity.

Does divorcing my spouse automatically revoke my codicil?

Only the provisions in the codicil affecting the ex-spouse or the ex-spouse's relatives are automatically revoked under MCL 700.2807. The rest of the codicil (and the underlying will) continues to control. See our will revocation guide for the divorce-revocation mechanics.

Update Your Michigan Will the Right Way

Most Michigan DIY situations are best solved with a fresh new will that expressly revokes the old. Codicils save nothing meaningful in effort and add real risk of ambiguity. The CreateMIWill Will Kit ($89) includes an attorney-drafted Michigan will template with the express revocation clause ("I hereby revoke all prior wills and codicils"), signing and self-proving affidavit instructions, and five companion documents. If a codicil is truly the right tool for your one-line change, the same template shows you exactly how to use the republication clause safely.