What a power of attorney does

A power of attorney is a legal document that lets one person (called the principal) authorize another person (called the agent or attorney-in-fact) to make decisions or sign documents on their behalf. The agent can act only in the ways the document permits — they cannot do anything outside those boundaries, and the power ends when the principal dies or revokes it.

The agent does not need to be a lawyer. They are often a family member, trusted friend, or professional like an accountant or financial advisor. What matters is that the principal trusts them to act in their interest and follow the specific instructions written into the document.

A power of attorney is not the same as a will. A will takes effect after death and distributes property. A power of attorney takes effect while the principal is alive (unless it is a "springing" power of attorney, which activates only if the principal becomes incapacitated) and ends at death.

Key Takeaways

  • The principal signs a power of attorney document that names an agent and lists exactly what decisions that agent can make.
  • The agent can act when ready after the document is signed, unless it is written to "spring" into effect only if the principal becomes unable to act.
  • The agent's authority is limited to what the document says — they cannot sell property, change a will, or make medical decisions unless the document explicitly permits it.
  • The principal can revoke the power of attorney at any time while they are mentally capable, and it automatically ends when the principal dies.
  • Banks, hospitals, and other institutions may ask to see the original document or a certified copy before they will accept the agent's signature.

How the agent's authority works in practice

Once the principal signs the power of attorney, the agent can begin acting when ready — unless the document says otherwise. For example, if the principal is in the hospital and unable to pay bills, a named agent with financial power of attorney can write checks, access bank accounts, and pay creditors right away.

The agent's power is only as broad as the document makes it. A financial power of attorney might allow the agent to manage bank accounts and investments but not to sell real estate. A healthcare power of attorney (also called a healthcare proxy or medical power of attorney) lets the agent make medical decisions but has nothing to do with money. Some documents are "general" and give broad authority; others are "limited" and cover only specific tasks.

The agent must act in the principal's best interest, not their own. If the agent misuses the power — for example, transferring the principal's money to themselves — they can be sued and held liable. Many states allow the principal to name a successor agent who takes over if the first agent dies, becomes incapacitated, or resigns.

Durable versus springing powers of attorney

A durable power of attorney stays in effect even if the principal becomes mentally incapacitated or unable to make decisions. This is the most common type because it ensures someone can act on the principal's behalf if they develop dementia, have a stroke, or fall into a coma. Without durability language, the power of attorney becomes void the moment the principal loses capacity — exactly when the agent's help is most needed.

A springing power of attorney does not set up until a specific event occurs, usually when a doctor certifies that the principal is incapacitated. The advantage is that the agent has no authority unless and until that trigger happens. The disadvantage is that proving incapacity takes time, and some institutions refuse to accept springing powers because the timing is unclear.

Most people choose a durable power of attorney because it is simpler and works when ready. The principal can still revoke it at any time while they are mentally capable, so the risk of the agent acting without permission is low if the principal chooses someone they trust.

What institutions need to see before accepting the agent's signature

Banks, investment firms, hospitals, and government agencies do not have to take the agent's word that they have authority. They will usually ask to see the original power of attorney document or a certified copy. Some institutions have their own power of attorney forms and ask the principal to sign those instead of accepting a third-party document.

If the power of attorney is old — sometimes institutions set a limit of five or ten years — they may refuse it and ask for a new one. The principal's signature on the document must be notarized in most states, and some institutions require that notarization to be recent (within the last year or so).

The agent should keep multiple certified copies of the power of attorney on hand. Getting certified copies from the court or a notary costs a small fee but saves time when dealing with multiple institutions. Some agents give a copy to the principal's bank, doctor's office, and other places where they expect to act, so the institution has it on file.

How the principal can change or end the power of attorney

The principal can revoke a power of attorney at any time, as long as they are mentally capable of understanding what they are doing. Revocation is usually done in writing — the principal signs a document stating that the power of attorney is no longer valid. That revocation should be notarized and given to the agent and any institutions that have a copy of the original document.

The principal can also replace the power of attorney by signing a new one. If the new document does not explicitly revoke the old one, both may be considered valid, which can create confusion. It is clearer to revoke the old document in writing before signing a new one.

If the principal becomes mentally incapacitated and did not sign a durable power of attorney, the only way to get someone authorized to act on their behalf is through a court process called guardianship or conservatorship. This is slower, more expensive, and more restrictive than a power of attorney, which is why planning ahead matters.

The difference between financial and healthcare powers of attorney

A financial power of attorney covers money and property: paying bills, managing bank accounts, selling real estate, filing taxes, and managing investments. The agent can do anything with the principal's finances that the document permits.

A healthcare power of attorney (also called a healthcare proxy, medical power of attorney, or healthcare agent designation) covers medical decisions: choosing doctors, consenting to surgery, deciding on life support, and accessing medical records. A healthcare power of attorney does not give the agent any control over money.

These are separate documents. The principal can name the same person as agent for both, or different people. For example, an adult child might be the financial agent while a spouse is the healthcare agent. The principal can also name co-agents who must agree before acting, though this slows decisions down and is less common.

What happens if there is no power of attorney

If the principal becomes incapacitated and has not signed a power of attorney, family members cannot automatically access their bank accounts, pay their bills, or make medical decisions. A family member who tries to act without authority can be held liable for any mistakes.

The only legal route is to ask a court to appoint a guardian (for personal and healthcare decisions) or conservator (for financial decisions). This process takes weeks or months, costs hundreds to thousands of dollars in legal and court fees, and gives the court ongoing control over the principal's affairs. The court may appoint someone the principal would not have chosen.

This is why financial advisors and elder law attorneys recommend signing a power of attorney while the principal is healthy and able to make clear decisions. It is inexpensive compared to guardianship and gives the principal control over who acts on their behalf.

Frequently Asked Questions

Can an agent use a power of attorney to change the principal's will?

No. A power of attorney does not give the agent authority to change, create, or revoke a will, even if the document says the agent has "broad" or "general" authority. The principal must change their will themselves, and they must do it while mentally capable. Some states allow the agent to help the principal update their will, but the principal must sign any changes.

What happens to the power of attorney when the principal dies?

The power of attorney becomes void when ready upon death. The agent has no authority to act after that point. If the principal's estate needs to be managed, the executor named in the will (or an administrator appointed by the court if there is no will) takes over those duties.

Can the principal still make decisions if they have signed a power of attorney?

Yes. Signing a power of attorney does not remove the principal's right to make their own decisions. The principal and agent can both act, though if they disagree, the institution may ask which one to follow. The principal can always revoke the power of attorney if they want to take back full control.

Does the agent have to tell the principal what they are doing?

The agent should keep the principal informed, especially if the principal is still capable of understanding. However, the document itself does not require regular reporting unless the principal writes that requirement in. If the principal becomes incapacitated, the agent should keep records of all actions taken and be ready to show them to the court or family members if asked.

What if the agent and the principal's family disagree about what the agent should do?

The agent's authority comes from the power of attorney document, not from family agreement. If family members believe the agent is misusing their power, they can file a lawsuit asking the court to remove the agent and order them to return any money or property. The agent must be able to show that their actions followed the document's instructions and served the principal's interest.