South Dakota: Revocable Trust Amendment Requirements
The short answer
South Dakota reverses the common revocability default: a trust is irrevocable unless its terms expressly reserve to the settlor a power to revoke or modify. The current statutes supply no universal signed-writing, will, intent, delivery, witness, notary, co-settlor, or trustee-protection fallback for exercising that reserved power, so the trust's terms require close review. A governing instrument may confer stated amendment powers on a trust protector; an agent needs express authority in both the power of attorney and trust and may act only when the settlor is incapacitated or not reasonably available; a conservator needs a court order and statutory hearing notice.
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This is the general rule in South Dakota. Ask about your specific facts and see which parts of current South Dakota law apply, with citations to the statutes.
| Governing law and revocability presumption | SDCL §§ 55-3-5 to -6; irrevocable unless trust terms expressly reserve to settlor a power to revoke or modify |
|---|---|
| Who may amend or restate | Settlor holding expressly reserved power; governing instrument may give a trust protector stated amendment powers. Agent or court-authorized conservator may act within statutory limits (§§ 55-1B-6, 59-12-23, 29A-5-420) |
| Trust method and exclusivity | Current statutes state no general strict- or substantial-compliance test or exclusivity rule; reserved power and any stated method come from trust terms (§ 55-3-6) |
| Alternative statutory method | No general signed-writing, will/codicil, delivery, or clear-and-convincing-intent fallback located in current Title 55 ordinary-trust scheme |
| Signature, witnesses, notary, and delivery | No universal amendment signature, witness, acknowledgment, notary, or trustee-delivery rule in §§ 55-3-5 to -6. Trust terms may supply formalities; § 29A-5-420's two-witness rule addresses a conservator-made will, not a trust amendment |
| Capacity standard | No direct-settlor trust-amendment-specific statutory capacity standard located in current Title 55; conservator route uses substituted-decision and protective factors (§ 29A-5-420) |
| Multiple settlors and contributed property | No general statutory contribution-based, community-property, joint-action, or other-settlor-notice allocation located in current Title 55 ordinary-trust scheme |
| Agent, guardian, conservator, and court authority | Agent: express authority in both POA and trust, only when settlor incapacitated or not reasonably available. Conservator: petition, court authorization, substituted-decision factors, and hearing notice. No parallel guardian amendment power stated (§§ 59-12-23(8), 29A-5-420) |
| Effective time, notice, and trustee protection | No universal effectiveness, trustee-receipt, beneficiary-notice, or no-knowledge safe harbor for exercise of the reserved power. Court-supervised conservator amendment requires advance hearing notice, including notice to trustee (§ 29A-5-420) |
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Requirements one by one
Revocability depends on an express reservation
South Dakota does not presume that an ordinary trust is revocable. Under S.D.
Codified Laws § 55-3-6, the trust is irrevocable unless its terms expressly
reserve to the settlor a power to revoke or modify. A particular trust must
therefore be checked for the existence, holder, scope, duration, and conditions
of the reserved amendment power before any method question is reached.
Section 55-3-5 directs the trustee to fulfill the trust purposes and follow the
trustor's directions as declared at creation or as subsequently amended. It
sends consent-of-interested-parties and court-approved modifications to chapter
55-18. That cross-reference does not create a general settlor-amendment method
for a revocable trust.
South Dakota states no separate procedure for a complete restatement. Replacing
all operative terms must fit the reserved amendment power and its conditions;
calling the document a restatement does not supply authority missing from the
trust.
The statutes supply no universal fallback method
The current Title 55 scheme states no generally applicable strict-compliance or
substantial-compliance test for a method stated in a revocable trust. It also
states no rule allowing a nonexclusive trust method to be bypassed.
Unlike a Uniform Trust Code fallback, the current South Dakota provisions do
not offer every settlor a signed writing, later will or codicil, delivered
record, or clear-and-convincing proof of intent when the trust states no method.
The reserved power's actual terms and other applicable law therefore require
individual review.
No universal amendment execution or delivery form
Sections 55-3-5 and 55-3-6 state no universal requirement that the settlor sign
before witnesses, acknowledge or notarize the amendment, or deliver it to the
trustee. They likewise state no universal trustee-acceptance condition. The
trust may impose one or more of those steps, and a separate deed, assignment,
account record, or other asset-transfer instrument may have its own formalities.
Section 29A-5-420 contains a two-witness rule for a will made or amended by a
conservator. The statute does not extend that sentence to a trust amendment, so
the will formality should not be imported into the trust document.
Capacity and multiple settlors are not given universal defaults
The current Title 55 ordinary-trust scheme states no direct-settlor
amendment-specific cognitive standard and does not direct courts to substitute
will or contract capacity. It also states no general rule allocating amendment
authority by each settlor's contribution, requiring all settlors to act, or
requiring notice to another settlor.
Those omissions do not establish that any person has capacity or that one
settlor may alter another's share. The trust, the reserved power, ownership of
the contributed property, and other applicable law require review.
A trust protector may hold instrument-defined amendment powers
Under § 55-1B-6, a trust protector's powers are those provided in the governing
instrument. The listed possibilities include amendments responding to tax or
law changes, changing beneficiary interests within the stated limits, modifying
powers of appointment, and amendments concerning restraints, distributions, or
administration. The instrument may provide other powers and discretions.
This is not a blanket statutory transfer of every settlor amendment power to
every trust protector. The governing instrument determines whether the office
exists and which powers it carries.
An agent needs two express grants and a triggering circumstance
S.D. Codified Laws § 59-12-23(1)(a) treats creation, amendment, revocation, or termination of
an inter vivos trust as authority requiring an express power-of-attorney grant.
Subsection (8) adds narrower conditions for a revocable trust: the settlor must
be incapacitated or not reasonably available, and the exercise must be
expressly authorized by both the power of attorney and the governing trust
instrument.
A conservator needs a court order and hearing notice
Under § 29A-5-420, a court may authorize a conservator, upon petition, to amend
or revoke a protected person's trust. The court primarily considers the
decision the protected person would have made, if ascertainable, and also
considers the person's needs, dependents, taxes, benefits, prior giving or
support, estate plan, life expectancy, possible end of the conservatorship, and
other pertinent factors.
Before the order, hearing notice must go to the protected person, estate-plan
beneficiaries, intestate successors, known recent legal or financial advisers,
and—before a trust is amended or revoked—the trustee. The section creates no
duty for a conservator to revise the estate plan. It states no parallel general
guardian power to amend the trust.
Effectiveness and trustee protection
The current reserved-power statutes state no universal rule making an amendment
effective on signing, delivery, receipt, acknowledgment, or another fixed event.
They also state no general beneficiary-notice duty or safe harbor for a trustee
who acts without knowledge of the amendment.
The conservator route has the specific pre-order hearing notices described
above. Section 55-3-24's thirty-day notice and effectiveness rule belongs to its
expressly stated irrevocable-trust consent or judicial modification route, not
to every exercise of a settlor's reserved revocable-trust amendment power.
What trips people up
- Assuming revocability. South Dakota requires an express reservation to
the settlor; silence makes the trust irrevocable under § 55-3-6. - Using the irrevocable-trust consent statute as the ordinary amendment
method. Section 55-3-24 addresses an irrevocable trust, not every exercise
of a reserved amendment power. - Inventing a signed-writing or delivery fallback. Current Title 55 states
no universal alternative method for a trust that lacks one. - Giving an agent authority from one document. The power of attorney and
trust must both expressly authorize the exercise, and the settlor must be
incapacitated or not reasonably available. - Treating trust-protector powers as automatic. Section 55-1B-6 makes them
dependent on the governing instrument.
Common questions
Must a South Dakota trust amendment be signed, witnessed, notarized, and
delivered to the trustee?
The current reserved-power statutes state no universal package of those
formalities. The trust's own method and other applicable law must be checked.
Section 29A-5-420's two-witness sentence concerns a conservator-made will, not a
trust amendment.
Can a power of attorney authorize an agent to amend the trust?
Only within § 59-12-23(8): the settlor must be incapacitated or not reasonably
available, and both the power of attorney and the governing trust instrument
must expressly authorize the exercise.
Can a conservator amend the trust?
The conservator must petition, obtain court authorization under § 29A-5-420,
and satisfy the hearing-notice process. The court applies the protected-person
decision and other statutory considerations.
Do all co-settlors have to sign?
Current Title 55 states no universal co-settlor allocation or all-signature
rule for exercise of a reserved power. The trust terms, reserved powers,
contributions, property law, and other applicable law require review.
Statutes and sources
- S.D. Codified Laws Title 55 index and §§ 55-3-5 to -6 — current trust
chapter structure, trustee direction, and the express-reservation rule.
Official Title 55 index,
§ 55-3-5, and
§ 55-3-6 (accessed
2026-08-11). - S.D. Codified Laws § 55-1B-6 — governing-instrument-defined trust
protector powers, including listed amendment powers. Official Legislature
text (accessed
2026-08-11). - S.D. Codified Laws § 59-12-23 — specific agent authority, the
incapacity-or-unavailability trigger, and express authority in both
documents. Official Legislature
text (accessed
2026-08-11). - S.D. Codified Laws § 29A-5-420 — court-authorized conservator amendment,
decision factors, hearing notice, and no duty to revise the estate plan.
Official Legislature
text (accessed
2026-08-11). - S.D. Codified Laws § 55-3-24 — the separate irrevocable-trust consent or
judicial modification route and its thirty-day notice rule. Official
Legislature text
(accessed 2026-08-11).
Source links
Every statute quoted above, linked, with the date we checked it.
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