Who this is for: Missouri residents creating a will who want to understand the execution rules in plain terms. What it covers: How Missouri will execution works: witness rules, signature requirements, self-proving affidavits, what wills can and cannot control, and how wills differ from trusts. Why it matters: Knowing exactly what Missouri law requires helps you avoid the most common will-drafting mistakes that lead to failed probate. Patrick Nolan is an estate planning attorney at Nolan Law Firm in Kirksville, Missouri.
The Nuts and Bolts Behind a Valid Missouri Will
You don’t get a second shot at a first will. If you die without one in Missouri, your assets won’t go where you thought—they’ll follow state-law blueprints, not your own plan. Missouri’s statutes lay out the rules. Get any piece wrong, expect trouble: arguments, court fights, sometimes the whole document gets thrown out. The only way forward is to know those lines and stick to them. Simple enough, but people trip anyway.
Who the Law Lets Write a Will
If you’re 18 or older in Missouri, or an emancipated minor (not common, but it happens), you can make a will—assuming you’re in your right mind when you do. “Sound mind” isn’t a phrase lawyers use lightly. You need to know what you own, who your family is, and what leaving a will means. If someone later questions your state of mind, it turns into a battle of facts—doctor’s notes, witness stories, all combed over by the court. Missouri doesn’t hand out second chances on competency.
No Telling, No Memory Games—Put It in Writing
Missouri doesn’t allow you to just tell someone your wishes on your deathbed. Oral wills, “nuncupative,” don’t hold water for the general population here. There’s the rare exception for active-duty military in very tight circumstances, but the ordinary system is simple: use paper. Scratch out a hand-written will and you’re not finished either—not unless you loop in witnesses and do things by statute. Most folks print everything out, but handwritten or typed, the paperwork needs proper eyes on it or it fails.
Missouri’s Tough Stance on Witnesses
For your will to breathe in Missouri, two adult witnesses must watch you sign your name, or watch you point at your name and admit you signed already. Both need to add their own signatures, standing in that same room, with you alive during the process—that last detail matters more than you’d think.
Those witnesses need to be over 18 and have their wits about them. Best practice: pick witnesses who don’t get a dime or any slice of your property under that will. If you let an heir watch and sign, the law punishes that person—they lose the gift. Missouri lets the will stand if there are two “disinterested” witnesses too, but if you get it wrong, someone’s gift may get erased. Ask any probate clerk; this is where people cause delays.
If You Can’t Sign, Have a Clear Backup—and a Paper Trail
If your hand shakes or you can’t sign for any reason, another person can sign for you, but that move needs to be open—done in your presence, under your direction. It’s a red flag moment; judges circle these documents for signs of someone leaning too hard on the testator. If someone else’s pen signs your name, make a record of how and why. Stave off the claims of undue influence with details up front.
Turning Your Will Into a Lockbox: Self-Proving in Missouri
Missouri allows you to make a will “self-proving.” Here’s what that does: if done right, it keeps your witnesses out of court after you’re gone, speeds up probate, and makes it much harder for anyone to claim your will is fake or forged. The mechanics are plain: you and your two witnesses sign an affidavit, ideally at that same table, under a notary’s watchful eye. The affidavit swears you all followed the law and no one got railroaded. It stays stapled to your will from day one.
Here’s what you’ll need for the self-proving layer to count:
- You, the testator, signing with at least two witnesses present—and the same for the affidavit section.
- A Missouri notary to stamp every signature.
- Language that fits Missouri law—specifically, Section 474.337 of the revised statutes. Get cute with phrasing and it might not count.
The law doesn’t force you to self-prove your will, but most lawyers urge it. Makes contests and court headaches less likely. Sometimes, it’s the only thing standing between order and chaos.
Landmines in Missouri Wills—and How People Still Step on Them
Most folks believe a will is just paperwork and trusted witnesses. That’s where mistakes creep in, and those mistakes make probate court busy. A few wrong decisions and your plan unravels fast. Missouri’s requirements are strict—no room for almosts.
Don’t Use an Heir as Witness—It Bites Back
If you let a person named in your will also serve as your witness, you’ve built a slow-motion problem. That person risks forfeiting their inheritance if the law isn’t strictly followed. Safer bet: use people who don’t stand to gain and document presence. Everyone in the room, no shortcuts.
A Will with Missing Signatures Might as Well Be Blank
If any required signature is missing—yours or a witness’s—your will’s nothing but a story no one can prove. Before that meeting breaks up, every line needs signing, including on the self-proving page if you use one. Otherwise the court tosses it.
Handwritten Is Not Enough—Witnesses Still Matter
Unlike some states, Missouri doesn’t recognize holographic wills, no matter how clearly you write your wishes in your own hand. It still needs all legal witnesses, or it’s as good as nothing. Hand-written notes found after death spark lawsuits, not certainty.
Wills from Elsewhere—Fine Print Can Save or Doom You
If you wrote your will in another state and move to Missouri, there’s a chance the document stands—if it matched the rules where and when you made it. Even so, take it to a Missouri lawyer. Local rules bite. One missed requirement can cost your beneficiaries months in probate, or much worse.
Old Wills Hanging On—A Common, Quiet Error
Missouri lets you rip up or formally revoke an old will at any time—including by writing a new, complete will. Trying to patch an old one with partial updates or “codicils” isn’t usually wise unless you follow every law to the letter—same witnessing, same steps. Play it safe: when in doubt, start fresh and keep the paper trail clean.
Bigger Picture Stuff: Life, Law, and the Missouri Will
Life doesn’t stay static—neither should your will. Missouri law intersects with life’s shocks: marriage, divorce, new children, loss. Each change can turn your clean plan sideways if you don’t address it directly.
Marriage and Divorce—Automatic Shifts, Missed Details
If you marry after you write your will, Missouri law still makes room for your new spouse unless you outright say otherwise. Divorce, on the flip side, cuts your former spouse out of your will unless you write it to survive divorce. After big changes, sit down with your document. Letting it ride on old language courts disaster.
Children Arriving Late—Pretermitted Heirs
A child born or adopted after you sign the will is called a “pretermitted heir.” Missouri law swings in to protect these kids, giving them a share unless you made it crystal clear you meant to exclude them. If you really mean to disinherit someone, use plain words and document it. The law tries to read between the lines if you don’t.
Some Assets Never See Your Will—Plan for That
Certain property slips past your will entirely—property held in joint tenancy, life insurance with named beneficiaries, retirement funds, transfer-on-death and payable-on-death accounts. These move by contract or operation of law. Make sure those designations fit your big plan or they’ll rip holes in your intended legacy.
Where to Store It, and Why It Matters
Once your will’s signed and stamped, it needs to be where someone you trust can get it. Missouri courts want the original, not a photocopy. Fireproof safe, bank box, or with your lawyer’s files—pick somewhere reliable. Tell your personal representative how to find it, or your best efforts might die in a locked drawer.
Big changes? Change the will. New job, divorce, another child—don’t wait. Every update should follow Missouri’s formalities, no shortcuts. Otherwise you leave your heirs with a fight you could have avoided.
Final Word
Missouri’s will statutes are blunt: do things right, or your last wishes mean nothing. Write it down, sign with witnesses, get your paperwork in order. That’s the path to a will that stands up under the hardest scrutiny. The law is there to enforce clarity, not sentiment. Map it out. Leave nothing to luck.
Frequently Asked Questions: Missouri Will Execution
What are the witness rules for a Missouri will?
Missouri requires two competent adult witnesses who observe the testator sign the will, or hear the testator acknowledge the signature, and then sign the will themselves in the testator presence. Both must sign during the same ceremony. They must be 18 or older and of sound mind. Best practice is to use witnesses who inherit nothing under the will.
Can someone else sign a Missouri will for the testator?
Yes. If the testator cannot physically sign, another person may sign on their behalf but only in the testator presence and at the testator express direction. The surrogate signer should not be one of the two required witnesses. This allows people with physical disabilities or serious illness to still execute a valid will.
Does a Missouri will need to be filed with a court before death?
No. Missouri law does not require a will to be filed with a court during the testator lifetime. After death, the will must be submitted to the Probate Division of the Circuit Court to begin probate. Many people store their will with their attorney or in a fireproof safe and inform their executor of its location.
What is a self-proving affidavit in Missouri?
A self-proving affidavit is a notarized statement signed by the testator and both witnesses at the time of will execution. Under Missouri law it allows the will to be admitted to probate without requiring witnesses to testify in court, speeding up the process and reducing complications. It is optional but strongly recommended.
What can a Missouri will NOT control?
A Missouri will cannot override beneficiary designations on life insurance, retirement accounts, or payable-on-death bank accounts. It also cannot control assets in a living trust, property in joint tenancy with right of survivorship, or assets subject to a Transfer on Death deed. Only probate assets are governed by the will.
What is the difference between a will and a trust in Missouri?
A Missouri will takes effect at death and goes through probate, a public court-supervised process. A revocable living trust takes effect immediately, avoids probate, and remains private. Most comprehensive Missouri estate plans include both: a trust for major assets and a pour-over will to capture anything left outside the trust at death.
