Revocable Trust Amendment Requirements in Missouri

Short answer Missouri permits amendment unless the trust expressly says it is irrevocable, but that default does not apply to an instrument executed before January 1, 2005. The settlor may substantially comply with a method in the trust; only when the trust provides no method may the settlor use another method manifesting clear and convincing evidence of intent, including a later duly probated will or codicil that identifies the trust or amended terms. Will-equivalent capacity, contribution-based co-settlor authority, either-document express authority for an agent, court-approved conservator or conservator-ad-litem authority, and a no-knowledge trustee safe harbor also apply.
State
Missouri
Statute checked
August 10, 2026
Sources
2 statutes

At a glance

Governing law and revocability presumptionMo. Rev. Stat. §§ 456.6-601–602; amendable unless terms expressly say irrevocable. Default excludes instruments executed before Jan. 1, 2005
Who may amend or restateSettlor; expressly authorized agent; conservator or conservator ad litem with supervising-court approval. Restatement is comprehensive amendment
Trust method and exclusivitySubstantial compliance with any trust method; alternative exists only when trust provides no method—not merely a nonexclusive method (subsection 3 of § 456.6-602)
Alternative statutory methodIf trust provides no method, any method manifesting clear-and-convincing intent, including later duly probated will/codicil identifying trust or amended terms (subsection 3 of § 456.6-602)
Signature, witnesses, notary, and deliveryTrust method or chosen will/codicil controls its formalities. No universal amendment writing, signature, witness, notary, trustee-delivery, or trustee-acceptance rule in § 456.6-602
Capacity standardSame capacity required to make a will (§ 456.6-601)
Multiple settlors and contributed propertyCommunity-property amendment requires joint spouses; other property follows each settlor's contribution. No prompt co-settlor notice rule (subsection 2 of § 456.6-602)
Agent, guardian, conservator, and court authorityAgent needs express authority in trust or POA. Conservator, or conservator ad litem if none, needs supervising-court approval; no guardian route stated (subsections 5–6 of § 456.6-602)
Effective time, notice, and trustee protectionApplicable method controls completion; no general co-settlor, beneficiary, trustee-receipt, or trustee-acceptance condition. Trustee without knowledge protected (subsection 7 of § 456.6-602)

Requirements one by one

Governing law and revocability presumption

Subsection 1 of Mo. Rev. Stat. § 456.6-602 permits amendment unless the trust terms expressly provide that the trust is irrevocable. The statutory default does not apply to a trust created under an instrument executed before January 1, 2005.

That cutoff makes the instrument's execution history material. The current default does not itself establish amendment authority for every older Missouri trust.

Who may amend or restate

The settlor is the ordinary actor. Subsections 5–6 of § 456.6-602 separately supply limited routes for an expressly authorized agent and a court-approved conservator or conservator ad litem. Trustee or beneficiary status alone does not confer amendment authority.

Missouri states no distinct lifetime-restatement route. A complete restatement is a comprehensive amendment and must satisfy the same authority and method rules.

Trust method and exclusivity

If the trust supplies a method, the settlor may substantially comply with any method it provides. The statutory intent fallback appears only when the trust terms provide no method.

Missouri therefore does not preserve that fallback merely because a stated method is nonexclusive. A method remains the statutory route whenever the trust provides one.

Alternative intent or probated-will method

When the trust provides no method, the settlor may use any other method manifesting clear and convincing evidence of intent. The statute expressly includes the terms of a later duly probated will or codicil that identify the trust being revoked or the trust terms being amended.

Probate and identification are part of Missouri's will route. A will or codicil that has not been duly probated does not satisfy the express example in subsection 3(2) of § 456.6-602.

Signature, witnesses, notary, and delivery

The trust's own method controls its required signing, witnessing, notarization, or delivery acts. A settlor using the statutory will-or-codicil example must have the duly probated and sufficiently identifying instrument described in subsection 3(2).

The other no-method fallback turns on clear and convincing evidence of intent. Section 456.6-602 itself states no universal amendment writing, signature, witness, acknowledgment, notarization, trustee-delivery, or trustee-acceptance requirement.

Capacity standard

Mo. Rev. Stat. § 456.6-601 makes the capacity required to amend a revocable trust the same as the capacity required to make a will. The same comparison covers creation, revocation, adding property, and directing the trustee.

Multiple settlors and contributed property

Community property may be amended only by both spouses acting jointly. For property other than community property, each settlor may amend the portion attributable to that settlor's contribution.

Subsection 2 of § 456.6-602 states no general prompt-notice duty to the other settlors when fewer than all act within their allocated authority.

Agent, guardian, conservator, and court authority

An agent may exercise amendment powers only to the extent expressly authorized by the trust terms or the power of attorney. Missouri uses an either-document rule rather than requiring the express grant in both.

A conservator—or a conservator ad litem if no conservator has been appointed— may act only with approval from the court supervising that fiduciary. Section 456.6-602 states no separate guardian amendment route.

Effective time, notice, and trustee protection

The applicable trust method or no-method evidentiary route determines when its required acts are complete. Section 456.6-602 states no general beneficiary notice, co-settlor notice, trustee receipt, trustee acknowledgment, or trustee acceptance condition for an amendment.

Under subsection 7, a trustee without knowledge of the amendment is not liable to the settlor or successors for distributions and other actions taken on the assumption that the old terms remain operative.

What trips people up

  • Using the fallback for a nonexclusive method. Missouri makes it available only when the trust provides no method at all.
  • Treating any later will as immediately operative. The statutory example requires a duly probated will or codicil that identifies the trust or amended terms.
  • Requiring express agent authority in two documents. The trust or the power of attorney may supply it.
  • Substituting an ordinary guardian. The statute names a conservator or, if none, a conservator ad litem and requires supervising-court approval.

Common questions

Must a Missouri amendment be written, witnessed, or notarized?

Section 456.6-602 states no universal formality for every route. The trust method controls when one exists; when none exists, any method may work if it manifests clear and convincing evidence of intent.

Can one settlor amend the entire trust?

Not automatically. Community property requires joint spouses for amendment; other property follows each settlor's contribution.

Does an agent need express authority in both the trust and power of attorney?

No. Subsection 5 of § 456.6-602 permits the trust or the power of attorney to supply the express authority.

Statutes and sources

  • Mo. Rev. Stat. § 456.6-601 — will-equivalent amendment capacity. Official Missouri Revisor text (accessed 2026-08-10).
  • Mo. Rev. Stat. § 456.6-602 — revocability default, methods, multiple settlors, agent and conservator authority, and trustee protection. Official Missouri Revisor text (accessed 2026-08-10).

Source links

Every statute quoted above, linked, with the date we checked it.

Mo. Rev. Stat. § 456.6-601 · accessed 2026-08-10
Mo. Rev. Stat. § 456.6-602 · accessed 2026-08-10
This page is general legal information about state-law amendment and complete restatement of an ordinary revocable trust, not legal, tax, fiduciary, property, creditor, Medicaid, marital-rights, litigation, or estate-planning advice about a particular trust, person, family, asset, deed, account, agent, guardian, conservator, trustee, or beneficiary. The trust's own terms, date, governing law, settlors, contributed property, retained powers, capacity, fiduciary authority, delivery, and later court orders can change the result. An amendment does not by itself transfer every asset, and a document that fails an exclusive trust method may be ineffective. Verified against the cited official statutes on the date shown; obtain prompt advice from a licensed estate-planning attorney before signing, delivering, relying on, or implementing an amendment or restatement.

What does Missouri law mean for your facts?

You just read the general rule. Ask your own question and see which parts of current Missouri law apply to your situation, with citations you can check.

Opens in Ezel Pro.

  • Starts from the statutes this survey is built on
  • Cites every source it relies on, so you can verify it
  • Chat, drafting and research in one workspace