Skip to main content
Missouri Will Contests
Support GuideMissouri13 min read

Missouri Will Contests

How to contest a will in Missouri: the grounds, who is an interested person, the six-month deadline under RSMo 473.083, and what a will contest involves.

By Settled Editorial

A will contest is a formal court challenge that asks a judge to declare a probated will invalid. In Missouri, a person interested in the estate files the contest with the clerk of the circuit court within six months after the will is admitted to or rejected from probate, or within six months after the first published notice of letters, whichever is later. Miss that window and the probate stands. (See RSMo 473.083.)

A contest is not a way to reargue how someone chose to divide their property. The challenge has to rest on a recognized legal ground, the person bringing it has to qualify as an interested person, and the six-month clock is unforgiving once it starts. This guide covers the grounds, who can file, where and when, no-contest clauses, and what the process involves.

Most Missouri wills are never contested. When the facts raise real concern, such as a caregiver who appeared late and took most of the estate, a signing during serious illness, or a signature that looks wrong, a contest may be the right path. Use this page as a map, then take your facts to a licensed Missouri attorney. This guide pairs with the Missouri will requirements guide for what makes a will valid and the Missouri intestate succession guide for who inherits if the will is set aside.

What a Will Contest Is and Is Not

A will contest asks the circuit court to declare that the will, or part of it, is invalid. If the challenge succeeds, the admitted will is set aside, and the estate passes either under an earlier valid will or, if none exists, under Missouri's intestate succession rules. (Source: RSMo 474.010.)

A contest is the wrong tool when the real complaint is that you expected more, that you dislike how the estate was divided, or that the personal representative is handling the estate poorly. That last problem is handled by objecting to the personal representative or the accounting filed with the probate division, not by attacking the will. Many contests turn on whether Missouri's signing rules were followed at all, so read the Missouri will requirements guide alongside this one.

Who Can Contest a Will in Missouri

Only a person interested in the probate of the will can bring a contest. That means someone with a financial stake, a person who would receive more if the will were thrown out. RSMo 473.083 treats an heir, a devisee, a trustee or trust beneficiary under another purported will of the same decedent, and a person who acquired an interest by purchase, gift, devise, intestate succession, mortgage, or lien as interested in the estate. (Source: RSMo 473.083.) The most common contestants are:

  • Heirs who would inherit by intestacy. People who would take under Missouri's intestate succession statute if there were no valid will, running from the surviving spouse and children out to parents, siblings, and more distant kindred depending on who survives. (Source: RSMo 474.010.)
  • Beneficiaries under a prior will. If an earlier will left you more than the current one, you have a stake in setting the later will aside.
  • Beneficiaries named in the contested will, usually when an earlier document treated them better.

Friends, distant relatives who would not inherit under intestacy, and charities named in no version of the will generally do not qualify. The test is plain: would you be better off financially if the will were declared invalid? If not, the court will not hear the challenge. A surviving spouse also holds separate protections, such as the elective share and family allowances, which are different remedies from a will contest and should be weighed on their own.

The Grounds for Contesting a Will

Missouri recognizes a short set of grounds for invalidating a will. The person bringing the contest carries the burden of proof. A will admitted to probate starts out presumed valid, and the contestant has to overcome that presumption with real evidence. Suspicion alone will not do it.

1. Lack of Testamentary Capacity

Missouri requires the testator to be of sound mind and at least eighteen years old (or an emancipated minor) when the will is signed. (Source: RSMo 474.310.) Sound mind means the testator understood, at the moment of signing:

  1. That they were making a will to dispose of their property at death
  2. The general nature and extent of what they owned
  3. The people who would naturally inherit from them, such as a spouse and children
  4. How the will distributed the property among those people

Courts measure capacity at the exact time of signing, not before or after. A dementia diagnosis does not automatically prove incapacity, because a person with cognitive decline can have a lucid interval and sign validly during it. To win on this ground, a contestant usually relies on medical records from around the signing date, testimony from doctors and caregivers, and observations from people who saw the testator near that time.

2. Undue Influence

Undue influence is the most commonly alleged ground and one of the hardest to prove. It applies when someone in a position of trust used pressure or control that overpowered the testator's free will, so the will reflects the influencer's wishes rather than the testator's own. Ordinary persuasion, even forceful persuasion, is not enough. Missouri courts look for a confidential relationship between the testator and the beneficiary, combined with activity by that beneficiary in procuring the will and a result that favors them.

Common red flags include a caregiver or new companion who appeared shortly before the will changed, a testator isolated from family, an unexplained break from an earlier estate plan, and a beneficiary who chose the drafting attorney or sat in on the signing. Because a confidential relationship can shift how the evidence is weighed, these cases usually turn on the pattern of circumstances rather than a single moment.

3. Fraud or Forgery

Fraud means the testator was deliberately deceived in a way that changed the will. Two forms come up. Fraud in the execution is where the testator was tricked about what the document was, told they were signing a power of attorney when it was a will. Fraud in the inducement is where a lie changed a gift, such as a false claim that a child had stolen from or abandoned the testator. Forgery is a separate claim that the signature on the will is not the testator's, or that the document was fabricated, and it usually calls for a forensic document examiner to compare the disputed signature against known samples.

4. Improper Execution

A Missouri will is valid only if it was signed the way the statute requires. Under RSMo 474.320, every will must be in writing, signed by the testator (or by another person at the testator's direction and in the testator's presence), and attested by two or more competent witnesses who subscribe their names in the presence of the testator. Missouri does not accept an unwitnessed handwritten will or a spoken will. A contest on this ground argues that a formality was missed: only one witness signed, a witness never actually saw the signing, the witnesses did not sign in the testator's presence, or a page was passed off as a valid will when it was never witnessed. Improper execution is often easier to prove than the mental-state grounds because it rests on procedural facts rather than the testator's state of mind.

5. Revocation by a Later Will

A will can also be attacked as no longer operative because the testator revoked it. Missouri allows revocation by a later will in writing, or by burning, cancelling, tearing, or obliterating the document, done by the testator or in the testator's presence and by the testator's consent and direction. (Source: RSMo 474.400.) If a valid later will exists, the earlier admitted document should not govern. A stray note in the margin or a spoken change of heart does not revoke a Missouri will, so a revocation contest turns on producing the later document or proving the physical act.

Where and When You File

In Missouri, a will is admitted to probate by the probate division of the circuit court in the county where the decedent lived at death. A challenge to that will is brought by a petition filed with the clerk of the circuit court of that county. The clerk then notifies the probate division and transmits a copy of the petition within ten days of filing, and the contest moves forward in the circuit court, where a judge or jury decides whether the will is valid. (Source: RSMo 473.083.) For the wider path an estate takes through the court, see the Missouri probate guide.

Timing decides these cases. Under RSMo 473.083, a person interested in the estate has to file the contest within six months after the date the will is admitted to or rejected from probate, or within six months after the first publication of notice of granting of letters on the estate, whichever is later. If no petition is filed within that period, the probate or rejection of the will becomes binding, and the right to contest is generally lost for good. The clock runs from those events, not from the date of death and not from when you learned about the will.

Two more timing rules matter once you file. The petitioner has to proceed diligently to secure and complete service of process on all defendants, and if service is not completed within ninety days after the petition is filed, the court may dismiss the petition at the petitioner's cost. Building a contest also takes time to gather records, locate witnesses, and retain an expert, so do not wait. For how a dispute stretches the rest of the estate calendar, see the Missouri probate timeline guide.

No-Contest Clauses

Some wills include a no-contest clause, also called an in terrorem clause, that tries to disinherit any beneficiary who challenges the will. A typical version reads: if any beneficiary contests this will, that person's gift is forfeited. The purpose is to scare beneficiaries out of litigating.

Missouri courts have enforced no-contest clauses, but how a court treats one depends heavily on the wording of the clause and the facts of the challenge, including whether the beneficiary had a good-faith, reasonable basis to sue rather than a fishing expedition. The stakes rise when a clause is present, because a beneficiary who contests without a solid footing can lose an inheritance they would otherwise have kept. Have the clause and your evidence reviewed by a licensed Missouri attorney before you file, and do not assume a clause is either automatically enforceable or automatically void.

The Process, Step by Step

  1. Talk to a probate litigator first. Will contests are litigation, not routine estate paperwork. A Missouri attorney who handles contested probate can assess standing, the available grounds, and the six-month deadline before anything is filed.
  2. Confirming the will was admitted. The probate division of the circuit court in the correct county is identified, the record shows whether the will was admitted or rejected, and the court file names who received letters as personal representative.
  3. Filing the petition. A contest begins as a petition filed with the clerk of the circuit court within the six-month window, stating the grounds and naming the personal representative and other interested persons as defendants.
  4. Completing service. All defendants are served, and diligence matters: service that is not completed within ninety days after filing can lead to dismissal, so it is not a formality.
  5. Discovery. Both sides exchange evidence: depositions of the drafting attorney, the attesting witnesses, caregivers, and family; subpoenas for medical and financial records; and expert reports on capacity or handwriting.
  6. Mediation and settlement. Many contests settle. A negotiated redistribution often costs far less than a trial and lets the family keep some control over the result.
  7. Trial. If the case does not settle, it goes to trial, where a judge or jury decides. The contestant must overcome the presumption that the admitted will is valid.

What a Contest Costs and Whether It Is Worth It

Will contests are expensive and slow. Even a fairly clean case can take a year or more and run well into five figures in attorney fees, plus costs for experts, depositions, and records. Relatives often end up testifying under oath about a loved one's mental state and private affairs. Before filing, weigh a few questions honestly:

  • Do you qualify as an interested person? Would you actually receive more if the will were set aside?
  • Do you have a real ground? Is there evidence of incapacity, undue influence, fraud, forgery, or a signing defect, not just disappointment?
  • Is there a no-contest clause, and how strong is your good-faith basis to challenge?
  • Is the likely recovery worth the cost and the family strain, and could mediation resolve it faster and for less?

If the answers point to a legitimate claim, move quickly. The six-month deadline is unforgiving, and the evidence is easiest to gather early. A contest can pull the whole estate off schedule, which affects the personal representative's duties and how creditor claims get paid while the dispute plays out.

Related Guides

This guide is general information about contesting a will in Missouri, not advice for your situation. Will contests are complex litigation, and the six-month deadline is short, so confirm your grounds, your standing, and the current deadline with a licensed Missouri attorney before you file.

Sources:

It is not legal advice.

Information current as of July 17, 2026

Settled Estate is not a law firm, and this content is for informational purposes only and does not constitute legal advice. Probate laws and procedures in Missouri can change. Consult with a qualified attorney for advice specific to your situation. Full disclaimer.

Need help with your probate case?

Answer a few questions to see whether Missouri probate is required and which process applies.

Take the 2-minute assessment
All Missouri guides← Back to all articles