Yes — a parent can name two siblings as co-agents under one power of attorney. The harder question is whether they should, and almost everyone gets the default rule backwards.
The short answer
Two siblings can share power of attorney. What matters is a single line in the document saying how they must act:
- Jointly — every decision needs both signatures.
- Independently (also written “jointly and severally”) — either one can act alone, without telling the other.
Most families assume the first. In roughly 30 states, the law assumes the second unless the document says otherwise.
On this page
The default rule people get backwards
When a parent names two children as co-agents, families picture a safeguard: two siblings, checking each other, agreeing before anything happens.
That is not what most powers of attorney actually do.
Under the Uniform Power of Attorney Act — adopted in some form by roughly 30 states and the District of Columbia — each co-agent may act independently unless the document expressly requires them to act together. One sibling can move money, sign paperwork, or close an account without the other’s knowledge, consent or signature.
If your parent named two of you and the document says nothing about how you must act, the odds are you each hold full independent authority. Many siblings only discover this after one of them has already done something the other disagrees with.
States that have not adopted the uniform act set their own defaults, and some presume the opposite. The only reliable answer is the wording of your document — read the clause naming the agents, and read it before you need it.
What each setup means day to day
| Acting jointly | Acting independently | |
|---|---|---|
| Routine bills | Both must sign | Either can pay |
| In an emergency | Stalls if one is unreachable | Whoever is available acts |
| Protection from a bad decision | Strong — neither acts alone | Weak — no built-in check |
| If siblings disagree | Deadlock, nothing happens | Each may act against the other |
| Institutions | Often slow, more paperwork | Simpler, but easier to misuse |
Neither column is obviously better. Joint authority buys oversight at the cost of speed; independent authority buys speed at the cost of oversight. What causes trouble is a family that believes it chose one and actually signed the other.
The problem banks create
Even a well-drafted co-agency runs into institutions that handle it badly.
Banks are cautious about multiple agents on one account, partly over fraud exposure. That can mean requiring both siblings to appear in person, refusing a transaction one sibling already approved, or applying their own internal rule rather than the document.
Joint authority makes this worse. If both signatures are required and one sibling lives three states away, every routine transaction becomes a scheduling problem — during exactly the period when a parent’s affairs most need attention.
Take the document to every bank, brokerage and insurer before you need to use it. Ask each one directly how they handle co-agents. Finding out that a bank wants both of you present is a nuisance in March and a crisis in an emergency room.
What co-agents owe each other
Co-agency is not a joint liability arrangement, and the rules surprise people in both directions.
You are generally not liable for what your sibling does. Under the uniform act, one agent is typically not responsible for another agent’s breach of fiduciary duty — unless you took part in it or helped conceal it.
But you cannot look away. An agent who actually knows that a co-agent has breached their duty, or is about to, is generally required to tell the principal. If the parent is already incapacitated, the obligation is to take reasonable steps to protect them. An agent who stays quiet can be held liable for losses that speaking up would have prevented.
Suspecting your sibling of mismanaging your parent’s money is not a family matter you can quietly sit on. It is a duty.
Both siblings also owe the usual fiduciary duties to the parent: act in their interest, stay within the authority granted, keep their money separate from your own, and keep records.
Usually a better structure
Most elder law practitioners steer families away from co-agents, for a simple reason: the problem co-agency is meant to solve is usually a fairness problem, and there are cleaner ways to solve it.
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One agent, one named successor
The most common recommendation. One sibling holds the authority; the other is named to take over if the first cannot serve. Clear lines, no deadlock, and the second sibling is still formally recognised.
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Split the roles
One sibling takes financial power of attorney, the other takes healthcare. Both have real responsibility, neither can block the other, and the division often matches who is actually better suited to each.
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Independent co-agents with a communication agreement
If your parent insists on naming both, independent authority usually works better than joint — then write a private agreement between siblings about what gets discussed before acting. It carries no legal force, but it prevents most of the conflict.
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Have the conversation before signing
Most co-agent disputes are really disputes about fairness that nobody voiced. A parent explaining why they chose a particular child, while they are well enough to explain it, prevents more conflict than any drafting choice.
If you are already co-agents and stuck
Start by reading the document to confirm whether you actually need to act together. A surprising number of deadlocks dissolve here, because the siblings never had to agree in the first place.
If you are genuinely jointly appointed and cannot agree, and your parent still has capacity, the simplest fix is theirs to make: they can revoke the document and sign a new one with a different structure.
If your parent has lost capacity, your options narrow considerably. One agent can resign, leaving the other to act alone. Failing that, unresolved disputes end up in probate court — slow, public, paid for out of your parent’s money, and corrosive to the relationship. It is worth considerable effort to avoid.
Frequently asked questions
Can my parent name two of us as co-agents?
Yes. The document should state clearly whether you must act jointly or may act independently — if it is silent, many states default to independent authority.
Can two siblings each have a separate power of attorney?
A parent with capacity can sign more than one document, and a later one may revoke an earlier one depending on its wording. Overlapping documents are a common source of confusion and institutional refusal. One document naming both of you is almost always cleaner.
What if one sibling refuses to cooperate?
If you hold independent authority, you can act without them. If authority is joint, the practical routes are the other sibling resigning, your parent signing a new document while they still have capacity, or court involvement.
Am I responsible if my sibling misuses the authority?
Generally not, unless you participated or helped conceal it. But if you know of a breach, you are usually required to report it, and staying silent can create liability of your own.
Sources
- Uniform Law Commission, Uniform Power of Attorney Act (2006), § 111 — coagents and successor agents
- N.C.G.S. § 32C-1-111; N.H. RSA § 564-E:111 — state enactments of the coagent provisions
- Consumer Financial Protection Bureau, Managing Someone Else’s Money: Help for Agents Under a Power of Attorney
Disclaimer: This article is general information, not legal advice, and reading it creates no attorney-client relationship. Power of attorney law varies significantly between states, and your authority depends on the wording of your own document. Consult a licensed attorney in your parent’s state of residence.
