Revocable Trust Amendment Requirements in South Dakota

At a glance

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).