Write a Will in Missouri: Laws & Costs

Under Missouri Revised Statutes § 474.320, a valid will must be in writing, signed by the testator (or by someone else at the testator's direction and in their presence), and witnessed by two competent individuals who sign in the presence of the testator. That's it — on the surface. But the word "competent" matters enormously.

A witness who is also a beneficiary under the will is called an "interested witness." Missouri doesn't automatically void a will because of this, but under § 474.330, the interested witness's bequest may be voided unless two disinterested witnesses also signed. Every time I've seen this go wrong, it's because someone asked a family member — often the very person inheriting the house — to witness the signing. That inheritance can disappear.

Missouri does recognize holographic wills — wills written entirely in the testator's own handwriting and signed by them — under § 474.320. No witnesses required. That sounds convenient. The problem is that any portion of the will that isn't in the testator's own handwriting (a preprinted form with handwritten fill-ins, for example) may not qualify as holographic, and the entire document can fail.

Oral wills, called nuncupative wills, are recognized in Missouri only in narrow circumstances — typically for personal property under $500 made during a final illness before witnesses. For real estate, retirement accounts, or anything of meaningful value, forget this option entirely.

The advertised price of a will is almost never the total cost. Here's what actually shows up.

A basic attorney-drafted will in Missouri runs $300–$800 for a single person, $500–$1,500 for a married couple with mirror wills. Add a pour-over will connected to a living trust, and you're looking at $1,200–$3,500. Estate planning attorneys in Kansas City and St. Louis typically charge on the higher end of these ranges; rural Missouri attorneys can run 20–30% less for comparable work.

Online services like LegalZoom or Trust & Will advertise Missouri-specific wills starting around $89–$199. What they don't prominently disclose: if your will is contested, you'll need an attorney anyway — and the cost of a contested will proceeding in Missouri probate court routinely runs $3,000–$15,000. A $150 DIY will that gets challenged costs the estate far more than the $500 attorney fee you skipped.

Probate itself — the court process validating the will — carries filing fees in Missouri starting around $100–$200 depending on county, plus attorney fees typically calculated as a percentage of the estate. Missouri follows the "reasonable compensation" standard under § 473.153, which courts have interpreted to allow 2–5% of estate value for straightforward estates. On a $400,000 estate, that's $8,000–$20,000 in probate fees.

One more line item nobody mentions: notarization. Missouri doesn't require a notarized will for validity, but a "self-proving" affidavit — which allows the will to be admitted to probate without witness testimony — does require a notary. Cost: $10–$25. Worth every dollar.

Choosing a DIY will saves $300–$1,200 upfront. Whether that's a good trade depends on one variable: complexity.

Option A — DIY or online template: Works reasonably well for single adults with no minor children, straightforward asset distribution, no blended family issues, and no real property in another state. The risk isn't that the form is wrong — it's that the signing ceremony goes wrong. Witnessed at the kitchen table with two relatives, one of whom inherits the car.

Option B — Attorney-drafted will: Costs more, but includes guidance on who can and cannot witness, whether a trust structure makes sense, beneficiary designation coordination (which most DIY services completely ignore), and potential estate tax exposure for larger estates. Missouri has no state estate tax as of 2026, but federal estate tax applies to estates over $13.61 million — a threshold relevant to fewer people, but worth knowing.

Honestly, the hidden cost in Option A isn't the template fee. It's the gap between what the document says and what your total estate plan actually needs. Retirement accounts and life insurance pass outside the will by beneficiary designation. If those designations are wrong or outdated, the will is irrelevant to those assets regardless of how perfect it is.

Missouri presents a few state-specific quirks that most national guides miss entirely.

Spouse's elective share: Under § 474.160, a surviving spouse can elect to take against the will — meaning they can claim a portion of the estate even if the will leaves them less. The elective share in Missouri equals 50% of the combined assets of both spouses, computed under a formula that includes nonprobate transfers. This isn't optional. You cannot disinherit a spouse in Missouri, full stop.

Children omitted from a will: Missouri has a "pretermitted heir" statute under § 474.240. If a child is born or adopted after the will is executed and the will doesn't account for that, the child may take an intestate share. This catches people who drafted a will before having kids and never updated it.

Missouri also allows a "transfer on death deed" (TODD) under the Missouri Nonprobate Transfers Law, § 461.025. This lets real property transfer directly to a named beneficiary at death, bypassing probate entirely. For many Missourians whose primary asset is a home, a TODD combined with a basic will covers most of the estate without a trust structure. Cost of recording a TODD: $24–$50 in most Missouri counties.

Quick note: Jackson County (Kansas City) and St. Louis City have different probate court procedures and forms than rural counties. If your estate involves real property in both jurisdictions, that complexity matters.

The signing ceremony is where most homemade wills fail. Missouri doesn't require the witnesses to read the will — they only need to witness the testator sign (or acknowledge a prior signature) and then sign themselves, in the testator's presence.

Who cannot be a witness: Anyone named as a beneficiary (see the interested witness problem above). The attorney drafting the will should not serve as a witness in most circumstances. The notary cannot also be a witness if you're doing a self-proving affidavit.

A valid Missouri signing checklist looks like this:

• Testator must be at least 18 years old and of sound mind at the time of signing
• Two competent, disinterested adults must be physically present and watch the testator sign
• Both witnesses sign in the testator's presence immediately after
• Optional but recommended: attach a self-proving affidavit, signed before a notary
• Store the original in a fireproof location — filing with Missouri probate court is not required but creates a record
• Notify your executor of the will's location

There's a version of this where a DIY will is genuinely fine. Single, no minor children, assets under $40,000 (Missouri's small estate threshold under § 473.097 for simplified procedures), and you just want to name a beneficiary for personal property. A properly signed DIY will works.

You need an attorney if any of the following apply: minor children who need a guardian named, blended family with children from prior relationships, real estate in multiple states, a disabled beneficiary who receives government benefits (a bequest could disqualify them from Medicaid or SSI without a special needs trust), a business interest, or an estranged family member likely to contest.

Every time I've seen a will successfully contested in Missouri probate, it wasn't because the testator had bad intentions. It was because the document couldn't defend itself — no attorney on record, ambiguous language, a signing ceremony nobody remembered clearly.