Whether both co-trustees have to sign depends first on the trust document and second on the state’s default rule. If the trust says co-trustees must act unanimously, both signatures are required. If the trust is silent and the state has adopted the Uniform Trust Code, co-trustees act by majority decision, which in a two-trustee setup still means both must agree. And even where the law would let one co-trustee act alone, banks, brokerages, and title companies often insist on every signature anyway.
What the Trust Document Says Controls
The grantor decides how co-trustees share power, and those instructions override any default state rule. Two trusts in the same state can have completely different signing requirements based on how each was drafted.
A trust can require unanimous consent for every action, so no co-trustee can move without the others agreeing. A trust with three or more co-trustees might instead allow decisions by majority vote. The grantor can also split duties: one co-trustee handles investments while the other manages distributions, each authorized to act alone in their assigned area. A grantor who appoints a family member alongside a professional advisor might give the professional sole authority over investment trades while requiring both signatures for distributions.
Before doing anything else, read the trust’s provisions on trustee powers, decision-making, and delegation. That language is where the answer usually lives.
Default Rules When the Trust Is Silent
If the trust doesn’t address how co-trustees make decisions, state law fills in. The rule depends mostly on whether the state has adopted the Uniform Trust Code.
The Modern Majority-Decision Rule
Under the UTC, co-trustees who cannot reach a unanimous decision may act by majority decision. This replaced the older common-law rule that required unanimity, a change intended to prevent a single dissenter from paralyzing administration.1National Conference of Commissioners on Uniform State Laws. Uniform Trust Code (2023) When only two co-trustees serve, majority rule effectively requires both, because neither alone is a majority.
The Traditional Unanimity Rule
States that have not adopted the UTC may still follow the older common-law standard requiring every co-trustee to consent to every action. If you’re administering a trust governed by a non-UTC state, check that state’s trust code carefully. The unanimity rule makes acting alone far riskier.
When One Co-Trustee Can Act Alone
Even in trusts that require joint action, the law recognizes situations where a single co-trustee can move forward without the other’s signature.
- Emergency or unavailability. If a co-trustee is unavailable due to illness, absence, or other temporary incapacity and prompt action is necessary to protect trust property or carry out the trust’s purposes, the remaining co-trustee can act. If the matter can wait, it should.1National Conference of Commissioners on Uniform State Laws. Uniform Trust Code (2023)
- Vacancy. If a co-trustee dies, resigns, or is removed and no replacement has been appointed, the remaining co-trustee can act for the trust without waiting for court approval.
- Delegated duties. One co-trustee can delegate specific functions to the other, but not any function the grantor reasonably expected them to perform jointly. Delegations are revocable unless the terms say otherwise, and in some states the delegation and acceptance must be in writing.
Routine tasks like paying recurring bills, collecting income, or maintaining insurance are the easiest to delegate. Major decisions involving investment strategy, large distributions, or selling real property generally fall on the other side of the line and need both signatures.
Banks and Title Companies Often Demand Both Signatures Anyway
This is where co-trustees hit the most friction. The trust or state law may authorize one co-trustee to act alone, but the institution on the other side of the transaction can refuse to cooperate without every signature.
Banks and Brokerages
Financial institutions often require all co-trustees to sign account documents, withdrawal authorizations, and transfer requests. Some will not recognize joint-authority co-trustees at all and insist the trust give each co-trustee independent authority. Others require both co-trustees to appear in person and sign a trust certification in front of a notary. These policies exist to limit the institution’s own liability, and they effectively override what the trust allows.
When a bank refuses to honor one co-trustee’s instructions, the practical options are limited: get the other co-trustee to cooperate, provide a certificate of trust proving independent authority, or escalate to the bank’s trust department.
Real Estate
Title companies and county recording offices generally require all co-trustees to sign deeds, deeds of trust, and other recorded instruments. Title insurers are cautious about issuing policies when only one co-trustee signs a conveyance, because a transaction executed without proper authority can be challenged later. If trust-owned real property is being sold, expect the title company to demand every co-trustee’s signature or clear documentation that the signing co-trustee has authority to act alone.
Proving Authority With a Certificate of Trust
A certificate of trust (sometimes called a trust certification or memorandum of trust) is the standard tool for proving a co-trustee’s authority without producing the full trust agreement. Under the UTC, the certificate must state, among other details, whether all co-trustees or fewer than all are required to exercise the trustee’s powers. Third parties who rely on the certificate in good faith are protected even if something in it turns out to be incorrect.
The certificate keeps the dispositive terms private. A bank or title company gets only the information it needs to verify signing authority. If a third party demands the entire trust instrument in bad faith rather than accepting the certificate, the UTC allows the co-trustee to push back and can hold that party liable for damages.
Federal Tax Returns: One Signature Is Enough
When a trust earns income, the co-trustees must file IRS Form 1041. The IRS requires only one co-trustee to sign, even when multiple fiduciaries serve.2Internal Revenue Service. Instructions for Form 1041 and Schedules A, B, G, J, and K-1 All co-trustees still share fiduciary responsibility for the return’s accuracy. The non-signing co-trustee should review it before filing, because a wrong position creates liability for every serving trustee.
What Happens If a Co-Trustee Signs Without Authority
A co-trustee who takes a major action without required consent exposes both the trust and themselves to serious risk. The transaction itself may be voidable. A beneficiary or the other co-trustee can petition a court to unwind the unauthorized act, and the trustee who acted alone can be personally surcharged for any resulting loss.
Courts treat unauthorized unilateral action as a breach of fiduciary duty. The acting trustee may lose the right to compensation for the period of the breach and may owe restitution for profits gained through the unauthorized transaction. Where self-dealing or misappropriation is involved, consequences can include removal from the trusteeship.
The Silent Co-Trustee Isn’t Off the Hook
A co-trustee who looks the other way doesn’t escape liability. Under the UTC, each co-trustee has an affirmative duty to exercise reasonable care to prevent a fellow co-trustee from committing a serious breach of trust and to pursue a remedy if one occurs.1National Conference of Commissioners on Uniform State Laws. Uniform Trust Code (2023) A co-trustee who notices unauthorized transactions and says nothing can be held jointly liable for the losses.
A co-trustee outvoted by a majority who disagrees with the decision has a way to protect themselves: document the dissent at or before the time of the action. A co-trustee who does this in writing is generally not liable for the majority’s decision unless the action is a serious breach of trust. Grumbling afterward is not the same as a written record.
When Co-Trustees Won’t Both Sign
Two co-trustees who disagree on a significant decision are, practically, deadlocked, because neither alone is a majority. It’s worth trying to resolve the impasse informally before spending trust money on legal proceedings.
The trust document itself may provide a tiebreaker mechanism, such as naming a third party to cast a deciding vote or requiring mediation. If the trust is silent, the co-trustees can agree to bring in a mediator on their own. Mediation costs less than litigation and keeps the dispute private.
When informal methods fail, the settlor, a co-trustee, or a beneficiary can petition the court. Courts have broad authority to interpret ambiguous trust language, order the trustees to take a specific action, appoint a special trustee to handle a disputed matter, or in severe cases remove a co-trustee. Under the UTC, a court may remove a co-trustee when lack of cooperation substantially impairs administration of the trust, but only if removal best serves the beneficiaries’ interests and a suitable replacement is available.1National Conference of Commissioners on Uniform State Laws. Uniform Trust Code (2023) Judges tend to view removal as a last resort rather than a way to break a one-time tie.
Pending a final decision on removal, a court can order interim relief, such as freezing certain accounts or appointing a temporary fiduciary to handle urgent business while the dispute is worked out.