What a Missouri last will and testament does
A will, or a last will and testament, is the document that gives instructions for what happens to what you own after you die. In Missouri, it lets you decide a handful of important things the state would otherwise decide for you.
A will lets you decide
Who inherits
Name the people and organizations who receive your home, accounts, and belongings instead of letting Missouri law decide.
Who manages your estate
Choose the personal representative who carries out your wishes, rather than leaving that choice to the court.
Who raises your children
Name a guardian for your minor children, instead of leaving that decision to a judge who never met your family.
You decide who receives your property. Without a will, Missouri law decides who inherits anything that passes through your estate, and the result does not always match what you would have chosen. A will lets you name the people and organizations you want to receive your home, your accounts, and your personal belongings.
You name your personal representative. This is the person who handles your estate by gathering assets, paying valid debts, and distributing what remains under the will. Missouri uses the term personal representative, though most people know the role as the executor. Naming this person yourself, instead of leaving the choice to the court, keeps the process in the hands of someone you trust. Name a backup, and ideally more than one. Years can pass between signing a will and needing it, and the person you first chose may no longer be able or willing to serve. If none of your named choices can step in, the court appoints someone instead, so a few alternates keep that decision yours.
You name a guardian for your minor children. For most parents, this is the single most important reason to have a will. It is where you say who should raise your children if you and the other parent are unable to. A judge has the final say, but your will tells the court and your family exactly who you would choose. Without it, that choice falls to a court that never met your family, and it can turn into a painful disagreement among relatives who each believe they know best.
What happens if you die without a will in Missouri
If you die without a valid will, the state decides who inherits the property that passes through your estate. Lawyers call this dying intestate. Missouri intestacy laws follow a fixed formula, the same applies for everyone, regardless of what you would have wanted.
The default rules do not know your family. They do not know whether you are close with one child and estranged from another, whether you meant to provide for a stepchild or an unmarried partner, or who you would have trusted to settle your affairs. Dying without a will tends to cause the most trouble for blended families, unmarried couples, parents of young children, and anyone with specific wishes that differ from the standard formula. A will lets you make those choices yourself, while you still can.
Missouri will requirements
Missouri has specific rules for making a will valid, and a will that is not executed correctly can be challenged or set aside, even when the person’s wishes were clear. In general, the person making the will, called the testator, must be at least 18 and of sound mind, the will must be in writing, it must be signed by the testator or by someone signing at the testator’s direction and in the testator’s presence, and it must be witnessed by two or more competent witnesses (RSMo § 474.320).
| Missouri will requirement | Plain-English meaning |
|---|---|
| In writing | The will needs to be a written document, not just spoken wishes. |
| Signed by the testator | The person making the will must sign it, or direct someone to sign for them in their presence. |
| Two or more competent witnesses | Witnesses must attest to the will by signing it in the testator’s presence. |
| Self-proving affidavit | Not required for validity, but it can make the will easier to admit to probate later. |
One Missouri detail surprises people. Missouri does not treat an unwitnessed handwritten note as a valid will simply because the person wrote it by hand. A handwritten document still has to meet Missouri’s ordinary requirements, including proper signing and witnessing. A note left in a drawer is unlikely to do what its author hoped.
Missouri also allows a will to be made self-proving with a notarized affidavit signed by the testator and the witnesses. This is not required for the will to be valid, but it makes the will easier to admit to probate later, because the court does not have to track down witnesses to confirm the signatures. Because these execution rules are precise, this is the part of will-making where do-it-yourself documents most often fail. This is where having a lawyer matters most. We do not just prepare the document and send you off to sign it on your own. We handle the signing with you and make sure it meets Missouri’s requirements, so a small mistake at the end does not undo everything the will was meant to do.
A will is only one part of the plan. Most families also need a durable power of attorney and a health care directive so someone can act if incapacity happens during life.
What a will does not do
None of this means a will is a weak tool. For many people, a well-drafted will paired with the right supporting documents is a complete and sensible plan. It helps to understand what a will handles on its own and what it leaves to other parts of your plan.
| A Missouri will can help you | A will does not do by itself |
|---|---|
| Name who receives property that passes through your estate | Avoid probate for property titled only in your name |
| Name a personal representative to handle your estate | Control assets with beneficiary designations or joint ownership |
| Nominate a guardian for minor children | Give someone authority to manage your finances while you are alive |
| Create inheritance instructions for children or other beneficiaries | Make medical decisions for you if you become incapacitated |
| Support a complete Missouri estate plan | Replace a trust, power of attorney, or health care directive when those tools are needed |
A will does not, by itself, avoid probate. It is a set of instructions for the probate court, not a way around it, so property that passes under your will generally goes through probate. That said, a will-based plan can still keep a great deal out of probate. Assets with proper beneficiary designations can pass straight to the people you name, and a beneficiary deed on your home or a jointly held account can do the same, leaving the will to cover whatever is left. If keeping your estate out of probate is a priority, that is a conversation about how to combine these tools, and sometimes about a trust.
A will does not control assets that already have a beneficiary. Retirement accounts, life insurance, and any account with a payable-on-death or transfer-on-death designation pass to whoever is named on that account, regardless of what your will says. Jointly owned property often passes to the surviving owner the same way. A forgotten beneficiary form can quietly override your plan, so those designations should be reviewed alongside the will.
A will does nothing while you are alive. A will takes effect only at death. It gives no one authority to help with your finances or your medical care if you become unable to act for yourself. That gap is filled by a durable power of attorney and a health care directive, which are separate documents.
Used together, these documents do more than any one of them can alone, and for many families a will sits at the center of a plan that works just fine.
Do you need a will or a trust?
This is the most common question in estate planning, and the honest answer is that it depends on your situation, not on which document is better.
| Question | Will-based plan | Revocable living trust |
|---|---|---|
| When does it work? | After death | During life if funded, and after death |
| Does it avoid probate? | No, not by itself | Can avoid probate for assets properly transferred into the trust |
| Can it name a guardian? | Yes, a will is the usual place to nominate a guardian for minor children | No, a trust does not replace the guardian nomination in a will |
| Is it simpler to maintain? | Usually yes | Usually requires more setup and funding |
| Best fit | Many straightforward family estate plans | Probate avoidance, privacy, blended families, or more complex asset planning |
A will-based plan often makes sense when your estate is relatively straightforward, you are not especially concerned about probate, and your main goals are to name beneficiaries, choose a personal representative, and nominate guardians for minor children. A revocable living trust in Missouri does more. It can hold your assets during your life and pass them to your beneficiaries without probate, which can mean more privacy and a smoother transfer. A trust also involves more setup and ongoing attention, including funding it properly so it actually holds your assets. Many plans use both, with a pour-over will that directs any assets left outside the trust into it at death.
Plenty of people come in certain they need a trust, having heard it is what everyone should do, and leave with a will-based plan that fits them better and costs less. The reverse happens too. The point of the conversation is to match the plan to your situation, not to sell you the longest document.
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A trust is one option, not the answer for everyone. Michael Boyd reviews your situation and tells you which documents — a will, a trust, a power of attorney, a health care directive — actually fit, instead of starting with the biggest plan.
Wills for parents of minor children
For parents of minor children, a will can also create a testamentary trust, which lets you name someone to manage inherited property for your children until the ages or milestones you choose.
In Missouri, a child who inherits outright generally gains full control of that property at 18. For most parents, that is a sobering thought. An eighteen-year-old who suddenly comes into a life insurance payout or the proceeds from a house rarely has the judgment to manage it well. A will can prevent that by holding what you leave in trust and releasing it gradually, at the ages or milestones you choose, with someone you trust managing it in the meantime. You can also keep the roles separate, so the person raising your children is not necessarily the person handling the money, if different people are better suited to each.
If you want more control over how a child receives money after age 18, that conversation may also involve a revocable living trust or a trust created through your will.
For young families, this is the heart of the plan. It is less about dividing property than about making sure the right people have authority and the right guardrails are in place if you are not there to provide them.
Updating an existing will
A will is not something you sign once and forget. Life changes, and an outdated will can cause as many problems as no will at all. It is worth reviewing your will after a major life event, such as marriage or divorce, the birth or adoption of a child, the death of someone named in the will, a significant change in your assets, or a move to or from Missouri.
Small changes can sometimes be made with a codicil, which is a formal amendment to an existing will. Larger changes are usually cleaner to handle with a new will that revokes the old one. Marking up a signed will by hand is not a reliable way to change it and can create confusion or invalidate provisions. If your will is more than a few years old, or any of those life events apply to you, it is worth a fresh look.
Online, DIY, and AI wills
Online forms and will-making software have been around for a while, and AI tools now do something similar. Any of them can produce a will that looks complete, and for a genuinely simple situation, any of them can be better than having nothing. The catch is the same for all of them, and it is worth understanding before you rely on one.
A tool generates a document. It does not have a conversation with you. The value of working with a lawyer is not mainly the words on the page, which are often similar. It is that an attorney knows what to ask. A short conversation surfaces the things a template never thinks to raise: a blended family, a child with special needs, a partner you are not married to, property held in an unusual way, or a beneficiary designation that quietly contradicts the will. A form cannot ask those questions, and an AI tool answers only what you already knew to tell it. The plan that fits you comes out of the questions, not the software.
The second problem is execution. Missouri’s witnessing requirements are specific, and a will that reads perfectly can still be invalid because it was signed incorrectly. A tool can hand you a document. It cannot make sure that document is valid when it counts, which is often the moment no one is left to fix it.
How The Boyd Law Firm helps with wills
When you work with The Boyd Law Firm, you work directly with attorney Michael Boyd from the first call to the signing. He drafts the wills himself, so the person answering your questions is the person doing the work, and nothing important gets handed to an intake team or a paralegal.
The firm works with individuals and families throughout St. Charles County, from St. Peters and St. Charles to O’Fallon and Wentzville. When probate is needed for a local estate, it is generally handled through the probate division of the St. Charles County Circuit Court, and a plan built with that in mind tends to go more smoothly for the people you leave behind.
The work starts with your situation, not a form. Before anything is drafted, the conversation is about your family and what you actually want to happen, not about filling in blanks. You do not need to know the legal terminology before you call. You just need to know that you want a clear plan.
Talk with a St. Charles County wills attorney
Estate Planning Consultation
Talk with a St. Charles County wills attorney
Whether you are creating your first will, updating an old one, or deciding whether a will or a trust fits your family, The Boyd Law Firm can help. Michael Boyd will give you a straight answer about what you need and what it involves.
5770 Mexico Road, Suite A
St. Peters, MO 63376
This page is general information about Missouri wills and is not legal advice.
Frequently asked questions about Missouri wills
Does a will avoid probate in Missouri?
No. A will does not avoid probate by itself. It tells the probate court how property should be distributed, but property held in your individual name may still go through probate unless it passes by trust, beneficiary designation, beneficiary deed, joint ownership, or another non-probate method.
Do I need a will in Missouri?
Most adults benefit from at least a basic will, especially if they own property, have children, or want to choose who handles their estate and who receives their property. Without a will, Missouri’s intestacy rules control whatever passes through your estate, and that formula may not match your wishes.
Can I write my own will in Missouri?
You can prepare your own will, but it still has to meet Missouri’s legal requirements. Missouri does not treat a handwritten note as a valid will just because someone wrote it by hand. Problems with signing, witnesses, unclear language, or conflicting beneficiary designations can create serious issues after death, which is when they are hardest to fix.
Who should I name as my personal representative?
Choose someone responsible and organized who can handle court filings, debts, property, and deadlines. It is wise to name a backup in case your first choice cannot serve when the time comes.
Can I name a guardian for my children in my will?
Yes. A will is the usual place to nominate a guardian for minor children. A court keeps final authority, but your written nomination gives the court and your family clear guidance about who you want to raise your children.
Should I have a will or a trust?
Some families are well served by a will-based plan. Others benefit from a trust, especially when they own real estate, want to reduce probate, have minor children, or have blended-family concerns. The right choice depends on your family, your property, and your goals.
When should I update my will?
Review your will after a major life change, such as marriage, divorce, a new child, the death of a beneficiary or your named personal representative, a move to or from Missouri, or a significant change in your assets.