Who this is for: Missouri adults who want a plain-language explanation of what actually counts as a legally valid will. What it covers: The foundational rules of Missouri will validity: who can make a will, how it must be written and signed, and what can invalidate it. Why it matters: Missouri law has no exceptions for good intentions. A will that misses the formal requirements is worthless, and the state decides who inherits instead. Patrick Nolan is an estate planning attorney at Nolan Law Firm in Kirksville, Missouri.
Foundations of a Valid Will in Missouri
People put it off. The business of death. Your wishes scribbled down or left unsaid won’t hold up once you’re gone. In Missouri, if you want your word to mean anything after you die, you need a legally sound will, done by the book. Missouri law spells out what counts. Miss the mark, and state law—not you—picks through your life’s lumberyard and hands it out as it sees fit.
The law’s not complicated, but it is strict. Missouri’s statutes and courts tell you who can sign, how the will has to look, and exactly what steps lock in your words. Nobody’s immune—fail to follow the rules and the state treats you like you had no will at all, no matter your intentions.
Who’s Allowed to Make a Will in Missouri?
Missouri sets the bar low, but it’s a real bar. You must be 18 or older, and your mind must be clear when you sign. “Sound mind” doesn’t demand college degrees or perfect health; it demands you know what you own, what a will does, and who counts as family. Old age or illness don’t, by themselves, kick you off the field. So long as you’re sharp at the moment of signing, you can set your terms.
You’re not required to hire a lawyer, but it’s a calculated risk. DIY wills are legal in Missouri, and plenty of people try. Simple mistakes—wrong witnesses, missing signatures, sloppy wording—are why so many homemade wills end up shredded in probate court.
How to Properly Write and Execute a Missouri Will
If you’re serious about your will standing up in court, Missouri expects you to do three things:
- Writing: The will must be on paper—typed or handwritten. Courts barely blink at oral wills, and only allow them under rare, emergency-like circumstances. For regular folks, always go with written.
- Testator’s Signature: You sign it. If you physically can’t, someone else can sign for you, but only while you’re present and telling them to.
- Witnesses: Two competent adults have to see you sign or hear you say the document is your will. They both must sign, right there before you.
A would-be inheritor can technically serve as a witness, but that’s muddy water. The law limits what a beneficiary-witness can take; at most, they get what they would have inherited if you’d died with no will at all. Simple rule: use two witnesses with nothing to gain and no ties to your property.
Handwritten (Holographic) Wills—Are They Valid?
In some states, people get away with handwritten, witness-free wills. Not Missouri. Writing the whole thing in your own hand means nothing if you don’t have two competent witnesses signing off, the same as any typed will. Missing witnesses? The court discards your effort.
Digital and Electronic Wills—Not in Missouri
No shortcuts here. Missouri doesn’t recognize electronic wills, digital signatures, or scanned copies. Only ink on paper, signed by hand. If you email your will or keep it on a flash drive, it won’t stand up when the time comes.
Key Details: Making Your Will Stand and Last
Self-Proving Affidavits
Missouri offers a shortcut if you prepare for it: a self-proving affidavit. When you make your will, you, the witnesses, and a notary all sign a sworn paper stating the rules were followed. If you do this, the probate court accepts your will automatically—no need to track down old witnesses or argue over who saw what. Saves your people a lot of headaches.
The notary is optional for the will. But the self-proving affidavit makes life simpler for your heirs. Lots of people skip it, to their family’s later regret.
Changing or Canceling Your Will
No legal lockbox here. Until you die or lose capacity, you can revoke or change your will as often as you see fit. You can destroy it—tear, burn, or otherwise obliterate it with clear intent. You can write a new will that says it replaces the old. You can make an official codicil—a formal amendment—using the same witness requirements as a full will.
Don’t just scribble updates or cross out names on your signed will. Missouri courts ignore such side edits unless properly formalized.
Where to Keep Your Will
A perfect will is worthless if nobody can find it. Missouri probate requires the original, signed document—no copies. People stash wills in fireproof safes, banks, or with their lawyer. Missouri even lets you officially deposit your will with the local circuit court for safekeeping during your life.
Tell someone you trust—your executor or a family member—where to find the will when it matters. If the original is missing, courts presume you revoked it. Suddenly the state’s intestacy laws decide who gets what.
Who Can Serve as Executor or Guardian
Your will should name the person you trust to carry out your last requests. Missouri courts almost always accept that choice, provided the executor is over 18, has a sound mind, and isn’t a convicted felon. If your will names a guardian for kids under 18, the court gives that serious weight, though it will always check what’s best for the children.
Where Missouri Wills Go Wrong
Witness Problems
The number one failing: people forget—or cut corners on—witnesses. No two competent adults in the room when you sign, no valid will, no matter how elegant the language. Both must be legally fit: adults, mentally capable, and not inheriting anything from you, if you want trouble avoided.
Using Wills from Other States or Bad Online Forms
Online will forms, out-of-state templates—these routinely leave your estate stranded. Missouri courts only honor Missouri law. If the will doesn’t fit state rules on language or signing, all or part of it can get tossed out. Don’t make your heirs pay for your shortcuts.
Missing Beneficiary Designations or Joint Ownership Rules
Not everything funnels through your will. Life insurance, retirement accounts, pay-on-death bank accounts—they all pass directly to named beneficiaries, no matter what your will says. Same goes for property held jointly with right of survivorship. The will only covers assets that go through probate. Every couple years, check those beneficiary forms and property titles. They dictate who walks away with what, not your will.
If You Die Without a Will in Missouri
No valid will? The state’s “intestacy” code slices up your holdings. Spouse and children first, then other relatives, and if the chain of kin runs cold, the state claims it all. Dying intestate erases your say—on guardians, gifts, or causes you cared about. The law fills the vacuum.
Why You Need to Revisit Your Will
Life blows through. Marriages, divorces, new children, deaths—the old will can turn obsolete overnight. Missouri law takes care of some changes, like erasing provisions for an ex-spouse after divorce. Still, the safest move is to formally review and update your will after any major twist, or every few years. Make sure your documents keep up with your life.
Get It Right, Spare Your Family Trouble
Your words only count if you follow Missouri law. Properly written and executed wills cut out confusion, limit family disputes, and ease the path through probate. None of it happens by accident. An experienced attorney won’t make your choices for you, but they’ll make sure your intentions survive you, on paper and in court—the only place it matters in the end.
Frequently Asked Questions: What Counts as a Valid Missouri Will
Who can legally make a will in Missouri?
Any person who is at least 18 years old (or a legally emancipated minor) and of sound mind may make a will in Missouri. Sound mind means the person understands what property they own, who their family and heirs are, what making a will means, and how these elements come together in a plan. Physical illness alone does not disqualify someone; the test is mental state at the moment of signing.
What does a valid Missouri will look like on paper?
A Missouri will must be a written document. It can be typed or handwritten. It must contain the testator signature or the signature of a designated person signing at the testator direction and in their presence. Two competent adult witnesses must also sign, in the testator presence, during the same event. There is no required format or magic language, but clarity matters enormously when the will is read after death.
Can a DIY or online will be valid in Missouri?
Yes, if it meets Missouri formal requirements. A will drafted without an attorney can be legally valid in Missouri if it is in writing, properly signed, and properly witnessed by two disinterested adults. The risk with DIY wills is execution errors and ambiguous language that can trigger disputes or partial invalidity in probate court. Simple mistakes kill otherwise valid wills.
What is undue influence and how does it invalidate a Missouri will?
Undue influence occurs when a person in a position of power or trust uses that relationship to substitute their wishes for the testator own free will. Missouri courts will invalidate a will if evidence shows the testator was coerced, manipulated, or unduly pressured into signing. Common situations include caregivers who are also beneficiaries, or family members who isolate the testator before signing.
What is the difference between a void and a voidable will in Missouri?
A void will is automatically invalid from the start, such as one executed by a minor or someone who completely lacked mental capacity. A voidable will appears valid but can be challenged in probate court on grounds such as undue influence, fraud, or duress. If no one challenges a voidable will within the statute of limitations, it may be admitted to probate despite the defect.
How should a Missouri will be stored after signing?
Missouri has no official will registry. Most estate planning attorneys recommend storing the original signed will with your attorney, in a fireproof home safe, or in a safe deposit box. The executor named in the will should know exactly where it is. A will that cannot be located after death may be presumed revoked under Missouri law, even if the testator never intended to revoke it.
