Missouri: Will Execution Requirements
The short answer
To sign a valid will in Missouri you must be at least 18 (or an emancipated minor) and of sound mind, put the will in writing, and sign it yourself (or have someone sign for you in your presence and at your direction). Two or more competent witnesses must then sign their names in your presence. Notarization is not required — an optional self-proving affidavit just speeds up probate. Missouri does NOT accept a handwritten (holographic) will, an oral will, or an electronic will; every will must be written and witnessed. A will that misses these steps is invalid, though Missouri will honor a will that was valid where you signed it.
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This is the general rule in Missouri. Ezel applies current Missouri law to your specific facts and answers with citations to the statutes.
| Governing law | Mo. Rev. Stat. ch. 474: § 474.310 (capacity), § 474.320 (will form, execution, attestation), § 474.330 (who may witness / interested witness), § 474.337 (self-proving affidavit), § 474.360 (out-of-state wills). Missouri follows the common-law attested-will model; it recognizes no holographic, oral (nuncupative), or electronic will, and has no harmless-error statute |
|---|---|
| Minimum age & capacity | 'Any person of sound mind, eighteen years of age or older or any minor emancipated by adjudication, marriage or entry into active military duty' may make a will (§ 474.310). Age 18, with an exception for an emancipated minor. 'Sound mind' is the ordinary testamentary-capacity standard (understanding the act, one's property, and the natural objects of one's bounty) |
| Writing & signature | 'Every will shall be in writing, signed by the testator, or by some person, by his direction, in his presence' (§ 474.320). Someone may sign for a testator who cannot, if done in the testator's presence and at the testator's direction. No statutory signature-at-the-end rule; no oral wills of any kind |
| Witnesses required | Two or more competent witnesses 'subscribing their names to the will in the presence of the testator' (§ 474.320). The witnesses must sign in the testator's presence; Missouri does not additionally require them to sign in each other's presence or at the same time. Any competent person may witness (§ 474.330.1). Interested-witness rule: a gift to a witness is not void, but the interested witness 'shall, unless the will is also attested by two disinterested witnesses, forfeit' the part of the gift exceeding their intestate share (§ 474.330.2). Being a creditor of the estate or the named executor does not make a witness interested (§ 474.330.3) |
| Notarization & self-proving | Notarization is NOT required to make a will valid — a notary is not a witness. Missouri offers an optional self-proving affidavit: the testator and witnesses acknowledge the will before an officer authorized to administer oaths (a notary), evidenced by the officer's certificate under official seal, attached to the will (§ 474.337). It may be added at execution or later. There is no 'notarized will' alternative to witnesses |
| Handwritten (holographic) wills | No. Missouri does not recognize holographic (handwritten, unwitnessed) wills — § 474.320 requires every will to be written AND attested by two witnesses, with no holographic exception. A will validly executed elsewhere, including a holographic one, may still be honored under § 474.360 |
| Electronic & remote wills | Not permitted. Missouri has not enacted electronic or remote-witnessed wills; § 474.320 requires competent witnesses to subscribe their names 'in the presence of the testator' (physical presence). Bills to authorize electronic wills have been introduced repeatedly (2023–2025) but none has passed |
| Harmless-error / curative doctrine | No. Missouri is a strict-compliance state with no harmless-error or substantial-compliance statute; a will that misses § 474.320's formalities — a missing witness, an unwitnessed handwritten change — is invalid, however clear the testator's intent. A will valid where it was executed, or under the testator's domicile law, is honored (§ 474.360) |
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Requirements one by one
Governing law
Missouri's will-execution rules are in the Probate Code, Chapter 474 of the Revised
Statutes. Section 474.310 says who may make a will, § 474.320 sets the writing, signature,
and witness rules, § 474.330 covers who may witness and the effect of a witness who also
inherits, § 474.337 provides the optional self-proving affidavit, and § 474.360 honors
wills validly signed elsewhere. Missouri uses the traditional common-law attested will — a
written document signed before two witnesses. It recognizes no handwritten (holographic)
will, no oral (nuncupative) will, and no electronic will, and it has no harmless-error rule
to excuse a botched signing.
Minimum age & capacity
To make a Missouri will you must be "of sound mind" and either "eighteen years of age or
older or any minor emancipated by adjudication, marriage or entry into active military
duty" (§ 474.310). So the age floor is 18, with an exception for an emancipated minor.
"Sound mind" is the ordinary testamentary-capacity standard: at the time of signing you
understand that you are making a will, know in a general way what you own, and know the
people who would normally inherit from you.
Writing & signature
"Every will shall be in writing, signed by the testator, or by some person, by his
direction, in his presence" (§ 474.320). If you cannot sign, another person may sign for
you, but only in your presence and at your direction. Missouri has no rule that the
signature appear at the very end of the document — and no oral will of any kind, so a
spoken deathbed wish is not a valid Missouri will.
Witnesses required
A Missouri will must be "attested by two or more competent witnesses subscribing their
names to the will in the presence of the testator" (§ 474.320). The key phrase is "in the
presence of the testator": the witnesses must sign while you are present. Unlike some
states, Missouri does not additionally require the two witnesses to sign in each other's
presence, or all at the same moment — though having everyone together is the safe practice.
Any person competent to testify may serve as a witness (§ 474.330.1).
The interested-witness rule is a partial "purge." A gift to a witness does not invalidate
the will, but under § 474.330.2 the interested witness forfeits the portion of the gift
that exceeds what they would have inherited had there been no will — unless the will is
"also attested by two disinterested witnesses." Being a creditor of the estate, or the
person named as executor, does not by itself make a witness interested (§ 474.330.3). The
clean fix is still to use two witnesses who inherit nothing.
Notarization & self-proving
A Missouri will does not have to be notarized to be valid — a notary is not one of the two
required witnesses. What notarization powers is the optional self-proving affidavit. Under
§ 474.337 the testator and the witnesses acknowledge the will "before an officer authorized
to administer oaths" (a notary), who attaches a certificate under official seal. A
self-proved will can be admitted to probate without hunting down the witnesses to testify.
The affidavit can be added when the will is signed or at any later date, and it is a
convenience, not a validity requirement.
Handwritten (holographic) wills
Missouri does not recognize holographic wills. Section 474.320 requires every will to be in
writing AND attested by two competent witnesses, with no exception for a will in the
testator's own handwriting. A handwritten page signed with no witnesses is not a valid
Missouri will. The exception runs the other way: under § 474.360, a will validly executed
under the law of the place where you signed it, or where you were domiciled — including a
holographic will from a state that allows them — is honored in Missouri.
Electronic & remote wills
Missouri does not permit electronic or remotely-witnessed wills. Section 474.320 requires
competent witnesses to subscribe their names "in the presence of the testator," which
courts read as physical presence, and Missouri has not enacted an electronic-wills statute.
Bills to authorize electronic wills have been introduced in several recent sessions
(2023–2025) as part of larger estate-planning packages, but none has passed, so a will that
exists only as a computer file or is "signed" electronically is not valid in Missouri
today.
Harmless-error / curative doctrine
Missouri is a strict-compliance state. There is no harmless-error or substantial-compliance
statute, so a will that misses a formality in § 474.320 — for example, only one witness, or
a handwritten change added later with no witnesses — is invalid, no matter how clearly it
reflects the testator's wishes. (Missouri courts have long applied this strictly, treating
unwitnessed alterations as legally ineffective.) The one built-in saver is § 474.360, which
honors a will validly executed under another state's law.
What trips people up
Missouri has no handwritten-will option. People often assume a signed note in their own
handwriting counts as a will. In Missouri it does not — every will needs two witnesses
(§ 474.320). There is no holographic will and no oral will; the writing-plus-two-witnesses
rule is the only way to make a valid Missouri will from scratch.
The witnesses sign in front of you — get them together. Section 474.320 requires the
witnesses to subscribe "in the presence of the testator." While Missouri does not
separately demand that the witnesses watch each other sign, the reliable practice is to
have both witnesses present with you at the same time, so there is no dispute later that
each signed in your presence.
Changing a signed will by writing on it does not work. Because Missouri has no
harmless-error rule, crossing out a gift or writing in a new number on an already-signed
will is not a valid change — those unwitnessed alterations are ineffective, and can even
raise questions about the original. Make changes with a properly executed codicil or a new
will.
A gift to a witness can be cut down. Under § 474.330.2, if a beneficiary also serves as
a witness, they forfeit whatever the gift gives them beyond their intestate share, unless
two other, disinterested witnesses also signed. Use two witnesses who inherit nothing.
Common questions
Does my Missouri will have to be notarized? No. Missouri requires two competent
witnesses, not a notary (§ 474.320). Notarizing the optional self-proving affidavit
(§ 474.337) just lets the will be admitted to probate without calling the witnesses to
testify; it is not required for the will to be valid.
Can I write my Missouri will by hand? You can write it by hand, but it still needs two
witnesses — Missouri does not recognize an unwitnessed handwritten (holographic) will
(§ 474.320). If you already signed a valid holographic will in a state that allows them,
Missouri will honor it under § 474.360.
Can I sign my Missouri will electronically or over video? No. Missouri has not adopted
electronic wills, and § 474.320 requires witnesses to sign in your physical presence.
Proposals to allow electronic wills have not become law, so a fully electronic or remotely
witnessed will is not valid in Missouri today.
How many witnesses do I need, and who should they be? Two competent witnesses who sign
in your presence (§ 474.320). Choose adults who are not beneficiaries — a witness who also
inherits can lose the excess of their gift over their intestate share under § 474.330.2.
Statutes and sources
- Mo. Rev. Stat. § 474.310 — capacity: sound mind and 18+, or an emancipated minor.
https://revisor.mo.gov/main/OneSection.aspx?section=474.310 (accessed 2026-07-11) - Mo. Rev. Stat. § 474.320 — will form: in writing, signed by the testator, attested by two or more competent witnesses in the testator's presence.
https://revisor.mo.gov/main/OneSection.aspx?section=474.320 (accessed 2026-07-11) - Mo. Rev. Stat. § 474.330 — who may witness; an interested witness forfeits a gift's excess over their intestate share unless two disinterested witnesses also sign.
https://revisor.mo.gov/main/OneSection.aspx?section=474.330 (accessed 2026-07-11) - Mo. Rev. Stat. § 474.337 — optional self-proving affidavit, acknowledged before an officer authorized to administer oaths and evidenced by a certificate under seal.
https://revisor.mo.gov/main/OneSection.aspx?section=474.337 (accessed 2026-07-11) - Mo. Rev. Stat. § 474.360 — a will validly executed under the law of the place of signing or the testator's domicile is honored in Missouri.
https://revisor.mo.gov/main/OneSection.aspx?section=474.360 (accessed 2026-07-11)
Source links
Every statute quoted above, linked, with the date we checked it.
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