Plenty of Missouri residents write their own will, take it to a bank or a UPS Store, have a notary stamp it, and file it away believing the job is done. In Missouri, that document may not be a valid will at all. A notary’s stamp doesn’t make a will legal. Witnesses do. And a homemade will that fails that test is treated as if it never existed.
Yes, You Can Write Your Own Will
Missouri doesn’t require a lawyer to draft a will. You can type it yourself, use an online form, or adapt a template. What the law cares about is not who wrote the document but how it was signed. If the signing ceremony is wrong, it doesn’t matter how clear your wishes are.
What Missouri Law Actually Requires
Under Section 474.320, a valid Missouri will must meet four requirements:
- You are at least 18 and of sound mind. You understand what you own, who your family is, and what the document does.
- The will is in writing. Missouri doesn’t recognize oral wills.
- You sign it, or someone signs for you at your direction and in your presence.
- Two competent witnesses sign it in your presence. This is the step most do-it-yourself wills get wrong.
Notice what isn’t on the list: a notary. Notarization is not required to make a Missouri will valid.
What a Notary Does, and Doesn’t Do
A notary’s stamp on the signature page doesn’t replace the two witnesses. A will signed by you and notarized, with no witness signatures, generally fails under Missouri law.
What a notary does is make the will self-proving. A self-proving affidavit is a sworn statement signed by you and your two witnesses in front of a notary. It lets the probate court accept the will without tracking down the witnesses to testify years later. It’s optional, but it can save your family time and money. We explain the self-proving process in more detail in our article on whether a will needs to be notarized in Missouri.
Handwritten Wills Don’t Get a Pass in Missouri
Some states accept a will written entirely in the person’s own handwriting, without witnesses. Missouri is not one of them. A handwritten will is held to the same two-witness rule as a typed one. A heartfelt letter in a desk drawer, signed but never witnessed, will not control who inherits.
Choose Witnesses Who Inherit Nothing
Missouri doesn’t void a will just because a beneficiary served as a witness. But unless two other disinterested witnesses also signed, that witness can lose any part of their gift that exceeds what they would have inherited without a will. Naming someone as your executor doesn’t make them an “interested” witness, but leaving them money does. The safest choice is two adults who receive nothing under the will.
Electronic Wills Are Now an Option
Since August 28, 2025, Missouri has recognized electronic wills signed with electronic signatures, including witnessing by live audio-video. They’re legal, but they come with technical requirements for the electronic record, the witnesses, and the self-proving certificate. A do-it-yourself electronic signing can fail just as easily as a paper one.
Common Do-It-Yourself Mistakes
Even when a homemade will is properly witnessed, these mistakes come up again and again:
- Handwritten changes after signing. Crossing out a name or adding a gift in the margin doesn’t change a signed will. It usually requires a new will or a properly executed codicil.
- No personal property list. Missouri allows a separate signed list for tangible items like jewelry and furniture, but only if the will refers to it.
- No backup beneficiaries. If a beneficiary dies before you, a gift without a contingent beneficiary can lapse or end up passing in ways you didn’t intend.
- No bond waiver or independent administration language. Leaving these out can make probate slower and more expensive.
Make Sure Your Will Actually Works
A will that fails the signing requirements leaves your estate to Missouri’s intestacy statute, a fixed family order that may look nothing like your wishes. If you’ve written your own will, or signed one at home with only a notary present, it’s worth having it reviewed while you can still fix it.
Mark Harford Law helps Missouri families prepare and properly execute wills through our estates practice in Chesterfield and surrounding counties. Contact us today to schedule a consultation.