What signing as power of attorney means
When you sign as power of attorney, you are signing a document on behalf of someone else—the person who gave you that authority. Your signature shows that you are acting in their legal capacity, not your own. The way you sign matters: you must write the principal's name (the person you represent) first, then add language that identifies you as their attorney-in-fact.
The correct format protects both you and the principal by making clear that you are not personally responsible for the obligation. If you sign your own name without identifying your role, you may be held personally liable for the debt or commitment, even though you had no personal stake in it.
Key Takeaways
- Sign the principal's name first, then write "by" and your name, followed by "as Power of Attorney" or "as Attorney-in-Fact."
- Keep a copy of the power of attorney document with you when signing on someone else's behalf, in case the other party questions your authority.
- Some institutions require you to show the original power of attorney document or a certified copy before they will accept your signature.
- Your signature is only valid for documents that fall within the scope of authority granted in the power of attorney—signing outside that scope has no legal effect.
- Different states have different rules about whether you must initial certain sections or provide additional documentation alongside your signature.
The correct signature format
Write the principal's name on the signature line first. Then on the same line or when ready below, write "by" followed by your name. After your name, add your title: "as Power of Attorney," "as Attorney-in-Fact," or "as POA." Some documents have a separate line for this information; others expect it all on one line.
Example: If you are signing for your mother, Margaret Walsh, the signature line should read: "Margaret Walsh, by James Walsh, as Power of Attorney" or "Margaret Walsh / by James Walsh, as Attorney-in-Fact." The exact spacing depends on the document, but the order is always the principal's name first, then your name with your role.
Print your name clearly below the signature line if there is space for it. This prevents confusion later if someone needs to verify who actually signed. Some financial institutions and government offices will not process a signature they cannot read, even if the power of attorney document is valid.
When you need to show the power of attorney document
Banks, insurance companies, and government agencies often require you to present the power of attorney document itself before accepting your signature. They want to verify that your authority is real and that it covers the specific transaction. Do not assume your signature alone will be enough.
Bring the original power of attorney document or a certified copy. A certified copy is a photocopy that has been stamped and signed by a notary or court clerk confirming it matches the original. Some institutions will accept a photocopy if you also show them the original to compare, but this varies by organization.
If the institution refuses to accept your signature without seeing the document, ask what form they need—original, certified copy, or notarized copy. Getting this answer before you sign saves time and prevents the document from being rejected later.
Scope of authority and what you can sign
You can only sign documents that fall within the powers granted to you in the power of attorney. If the document says you have authority over financial matters, you cannot sign medical decisions. If it limits you to bank accounts at one specific bank, you cannot sign for accounts at another bank.
Read the power of attorney document carefully before signing anything. Look for language that says "limited to" or "excluding" or "only for the purpose of." These phrases narrow your authority. If you are unsure whether a particular document is covered, contact the person who created the power of attorney and ask before you sign.
Signing outside your authority does not make the document valid. The other party may accept your signature, but if the principal later disputes it, the signature can be voided. This creates liability for you and confusion for everyone involved.
Notarization and additional requirements
Some documents require your signature to be notarized—that is, witnessed and certified by a notary public. This is common for real estate transactions, certain financial documents, and court filings. Check the document itself or ask the institution whether notarization is required before you sign.
If notarization is needed, you must sign in front of the notary. Bring your photo ID and the power of attorney document. The notary will watch you sign, verify your identity, and then stamp and sign the document themselves. This process usually costs between $5 and $15 per signature.
Some states also require you to initial specific sections of certain documents when signing as power of attorney. This is especially common in real estate and healthcare contexts. Ask the other party or the institution whether initialing is required in your state before you sign.
Common mistakes to avoid
Do not sign your own name on the principal's signature line. This makes it appear that you are the one entering into the agreement, not acting on behalf of someone else. It also creates personal liability for you.
Do not assume that a photocopy of the power of attorney is sufficient without checking first. Many institutions require a certified copy or the original. Bringing the wrong version wastes time and may force you to come back later.
Do not sign documents that are not clearly covered by the power of attorney. If you are uncertain, ask the principal or a lawyer before you sign. Signing outside your authority can be challenged later and may create legal problems for both you and the principal.
Do not lose track of what you have signed. Keep copies of every document you sign as power of attorney, along with a copy of the power of attorney itself. This protects you if questions arise later about what you were authorized to do.
What to do if an institution refuses your signature
Some banks and government offices have their own rules about power of attorney signatures and may reject yours even if it is correct. Ask the institution what specific problem they see. Common reasons include: the power of attorney is too old (some institutions set their own age limits), the document does not match their internal template, or they need a certified copy instead of an original.
If the institution has a specific form they require, ask them to provide it. Some will let you use their own power of attorney form instead of the one the principal signed. This is legal in most states, but it requires the principal's signature on the new form.
If the institution continues to refuse, ask to speak with a supervisor or the legal department. Explain that the power of attorney is valid under state law and that you are signing within your authority. If they still refuse, you may need to contact a lawyer to send a letter on your behalf, or the principal may need to contact the institution directly.
Frequently Asked Questions
Do I need to write "power of attorney" every time I sign, or can I just write "POA"?
Either is legally acceptable, but "Power of Attorney" or "Attorney-in-Fact" is clearer and less likely to be questioned. If the document has a specific line for your title, follow the format shown. When in doubt, spell it out fully.
What if the power of attorney document is very old—can I still use it to sign?
A power of attorney does not expire unless the document itself says it does or unless the principal revoked it. However, some banks and institutions set their own rules and may refuse to accept a power of attorney that is more than a few years old. If this happens, ask the institution what they need, or contact the principal about signing a new power of attorney.
Can I sign as power of attorney if the principal is still alive and able to sign themselves?
Yes. A power of attorney remains valid as long as the principal has not revoked it, regardless of whether the principal is able to sign. However, if the principal is present and able to sign, the other party may ask them to sign instead. You should only sign if the principal has asked you to or if they are unavailable.
What happens if I sign something I was not supposed to sign as power of attorney?
The signature may still be valid if it falls within your authority, even if you made a mistake about whether to sign. However, if you signed outside your authority, the principal can challenge the signature and may hold you liable for any losses. If you realize you made a mistake, tell the principal and the other party when ready.
Do I need to tell the principal every time I sign something as power of attorney?
This depends on the arrangement between you and the principal. Some principals want to be informed of every transaction; others give you broad authority to act without reporting. Check the power of attorney document and any instructions the principal gave you. At minimum, keep records so you can report to the principal if they ask.