What it means to sign with power of attorney

When you sign a document with power of attorney, you are signing on behalf of someone else — the person who gave you that authority. You do not sign your own name. Instead, you sign the name of the person you represent, then add language that shows you are acting as their attorney-in-fact (the legal term for someone holding power of attorney).

The correct format is: the principal's name (the person who gave you power of attorney), followed by their signature line, and then you sign your own name below it with a notation like "By [Your Name], Attorney-in-Fact" or "By [Your Name], as Power of Attorney for [Principal's Name]." Some documents have a specific signature block already printed for this purpose.

The document itself — the power of attorney form — must already exist and be in effect before you sign anything on someone else's behalf. You cannot create authority to sign; that authority has to be given to you first in writing by the principal.

Key Takeaways

  • You sign the principal's name, not your own, followed by notation showing you are their attorney-in-fact.
  • The power of attorney document must be signed and notarized (in most cases) before you can use it to sign anything else.
  • Different documents may require different signature formats, so check the specific form or ask the organization accepting it.
  • Some institutions require you to show them the original power of attorney document before they will accept your signature on their forms.
  • If the power of attorney is limited to certain types of documents or decisions, you can only sign within those limits.

The power of attorney document must be in place first

Before you can sign anything on someone else's behalf, the principal must have created and signed a power of attorney document. This document names you as their attorney-in-fact and describes what authority you have — whether you can handle all financial matters, only real estate, only healthcare decisions, or something narrower.

In most states, the power of attorney document itself must be notarized. That means a notary public watches the principal sign it and verifies their identity. Some states allow certain powers of attorney (like healthcare directives) to be witnessed by two people instead of notarized, but financial powers of attorney almost always require notarization.

The principal keeps a copy, and you should have a copy as well. Many institutions will ask to see the original or a certified copy before they accept your signature on their documents. Do not sign anything until you have the power of attorney document in hand and have confirmed it covers what you are about to sign.

How to format your signature on the actual document

The signature line should show the principal's name first. If the document has a blank line for a signature, write the principal's name on that line, then sign below it with your own signature and add a title that identifies you as their attorney-in-fact.

Common formats include:

  • [Principal's Name], by [Your Name], Attorney-in-Fact
  • [Principal's Name], by [Your Name], as Power of Attorney
  • [Principal's Name] / By [Your Name], its Attorney-in-Fact

If the document has a printed signature block with spaces for multiple lines, use it as written. Some forms have a line for the principal's name, a line for your signature, and a line for your title — fill each one in order. If you are unsure about the format, contact the organization that will receive the document (a bank, real estate office, court, or government agency) and ask how they want it signed.

What institutions need to see before accepting your signature

Banks, title companies, government offices, and other organizations will not accept a signature made under power of attorney without proof that your authority is real. Most will ask to see a copy of the power of attorney document itself.

Some institutions keep a copy on file after the first time you use it. Others require a new copy every time. A few will ask for a certified copy — one stamped by the court or notary that issued it — rather than a photocopy. Call ahead and ask what they need before you show up to sign.

If the power of attorney is old (more than a few years), some banks and government agencies may ask for a new one, even if it is still legally valid. This is not a legal requirement in most places, but it is a business practice to reduce their risk. If an institution refuses to accept your power of attorney, ask them in writing what specific language or format they need, and consider having the principal consult an attorney about updating it.

Signing within the limits of your authority

You can only sign documents that fall within the scope of authority the principal gave you. If the power of attorney says you can handle "all financial matters," you have broad authority. If it says you can only "manage real estate transactions," you cannot sign a bank loan or healthcare form.

Read the power of attorney document carefully before you sign anything. If you are unsure whether a particular document falls within your authority, contact the principal and ask, or consult an attorney. Signing outside your authority can expose you to legal liability and may make the document invalid.

Some powers of attorney have an expiration date or become invalid if the principal becomes incapacitated (called a "springing" power of attorney). Check the document to see if there are any time limits or conditions on your authority.

Special situations: healthcare, real estate, and financial accounts

Healthcare documents often have their own signature requirements. A healthcare power of attorney (also called a healthcare proxy or medical power of attorney) may need to be signed in front of witnesses rather than a notary, depending on your state. Hospitals and doctors may have their own forms they want you to sign instead of using the original power of attorney document.

Real estate transactions usually require the power of attorney to be notarized and sometimes recorded with the county. Title companies and real estate attorneys often have specific requirements about how the signature should appear on the deed or mortgage. Contact the title company or attorney handling the transaction before you sign.

Financial institutions — banks, investment firms, insurance companies — often have their own power of attorney forms they want the principal to sign instead of accepting a general power of attorney document. If you are opening an account or making a transaction on someone's behalf, ask the institution what form they need before the principal signs anything.

What happens if you sign incorrectly or without authority

If you sign a document without the proper power of attorney in place, or if you sign outside the scope of your authority, the document may be invalid. The other party (a bank, seller, lender, or government agency) may refuse to honor it, or they may pursue legal action against you for signing without authority.

If you sign with the correct authority but use the wrong format, the document may still be valid — many institutions will accept it and move forward. However, it is better to get the format right the first time to avoid delays or questions.

If you make a mistake on a document you have already signed, do not cross it out or write over it. Ask the principal to sign a new copy of the document, or contact the institution that will receive it and ask whether they can accept a corrected version.

Frequently Asked Questions

Can I sign a power of attorney document for someone else?

No. The principal must sign the power of attorney document themselves (or have someone sign it on their behalf if they are physically unable, depending on state law). You cannot create power of attorney for someone else. Once it is signed and notarized, you can then use it to sign other documents on their behalf.

What if the principal is no longer able to sign the power of attorney?

If the principal has lost the ability to sign (due to illness, injury, or cognitive decline), they cannot create a new power of attorney. If no power of attorney exists, family members may need to go through a court process called guardianship or conservatorship to make decisions on their behalf. This is why it is important for people to create a power of attorney while they are still able to do so.

Do I need to tell the principal every time I sign something on their behalf?

You should keep the principal informed of major decisions and transactions, especially if they are still able to communicate. However, the power of attorney gives you the legal right to sign without asking permission each time, as long as you stay within your authority. If the principal objects to something you have signed, they can revoke the power of attorney.

What if an organization refuses to accept my signature under power of attorney?

Ask them in writing what specific problem they have with the document — whether it is the format, the age of the power of attorney, or something else. Some institutions have their own forms they prefer. If they continue to refuse, you may need to have the principal consult an attorney, or you may need to pursue the matter through a different channel (such as a different branch of the same bank, or a court order).

Does the power of attorney end when the principal dies?

Yes. Once the principal dies, your authority to sign on their behalf ends when ready. After that point, only the executor or administrator of the estate (appointed through the will or by the court) can sign documents on behalf of the deceased person's estate. Do not sign anything after the principal's death unless you have been appointed as executor or administrator.