To write an authorization letter, put in writing that you are giving a named person permission to act on your behalf for a specific task, name the institution that will receive the letter, spell out exactly what the representative may and may not do, set a start and end date, and sign and date the page. Banks, hospitals, and government offices reject vague or unsigned letters routinely, so precision is the point.
An authorization letter is narrow and informal. It covers a defined task within a defined window: picking up a package, collecting a bank statement, retrieving a document. It does not create a legal agency relationship and usually does not need to be filed anywhere. If you need someone to manage finances while you’re away for months, sign legal documents, or make decisions if you become incapacitated, you need a power of attorney instead. Banks will refuse an authorization letter for major account actions like closing accounts, applying for loans, or changing beneficiaries, and will ask for a properly executed power of attorney.
Gather the Details Before You Start
Incomplete information is the fastest way to get a letter rejected, and vague information is a close second. Pull these together first:
- Your full legal name, address, phone number, and email as the grantor.
- Your representative’s full legal name and contact details. Some institutions also ask for a copy of the representative’s government-issued ID.
- The name, department, and address of the bank, hospital, or agency that will receive the letter.
- A precise description of what the representative can do. “Withdraw up to $500 from checking account #XXXXXX” is useful. “Handle my banking” is not.
- A start date and an end date, or a statement that the authorization covers a single transaction.
- Any account numbers, policy numbers, case numbers, or document names tied to the task.
Specificity does two jobs. It makes the letter easier for the recipient to accept, and it limits what your representative can be asked to do in your name. If you want them to pick up one prescription, name the medication. If you’re authorizing access to financial statements, name the accounts and the date range.
Structure the Letter Like a Business Letter
Authorization letters follow a standard business-letter format, and the format itself signals that the document is serious. Put your full name, address, and contact details at the top left. Add the date below. Then the recipient’s name or department, title, and mailing address. Open with “Dear [Recipient’s Name]” or “To Whom It May Concern” if you don’t know who will handle it.
The first paragraph of the body states the purpose: you are authorizing a specific person to act on your behalf. Name both parties by full legal name. The next paragraph lists exactly what the representative may do, and then what they may not do. Explicit limitations keep your representative from being asked to take actions you didn’t intend. Close with a line inviting the recipient to contact you to verify the letter, sign off with “Sincerely” or “Respectfully,” leave room for your signature, and print your name beneath.
Sample Authorization Letter
Adapt this to your situation, but keep the structure.
Jane A. Smith
456 Maple Avenue
Austin, TX 78701
jane.smith@email.com
(512) 555-0142
January 15, 2026
Customer Service Department
First National Bank
200 Congress Avenue
Austin, TX 78701
Dear Customer Service Representative,
I, Jane A. Smith, residing at 456 Maple Avenue, Austin, TX 78701, hereby authorize my brother, Michael R. Smith (date of birth: March 10, 1990), to act on my behalf regarding my checking account (#XXXXXXX789) at First National Bank from January 15, 2026 through April 15, 2026.
During this period, I grant Michael R. Smith permission to:
– Withdraw funds up to a total of $3,000
– Make deposits into the account
– Request account statements for January through March 2026
This authorization does not permit Michael R. Smith to close the account, open new accounts, apply for loans, or change beneficiary information.
Please contact me at (512) 555-0142 or jane.smith@email.com to verify this authorization. A copy of my government-issued photo ID is attached for your reference.
Sincerely,
[Signature]
Jane A. Smith
Notice three things: a dollar cap on withdrawals, an explicit list of actions the representative cannot take, and a direct line for the bank to verify the letter with the account holder. Those are the details that separate a letter the bank accepts from one it hands back.
Signatures and Notarization
Whether a handwritten signature is required depends entirely on who is receiving the letter. Some institutions still insist on one. The FDA, for example, requires authorization letters to be “signed with a traditional handwritten signature.”1U.S. Food and Drug Administration. Authorization Letter Many banks, notary offices, and government agencies take the same approach for in-person transactions.
Federal law has recognized electronic signatures as legally valid since 2000. Under the Electronic Signatures in Global and National Commerce Act, a signature or record “may not be denied legal effect, validity, or enforceability solely because it is in electronic form.”2Office of the Law Revision Counsel. United States Code Title 15 Section 7001 USCIS, for instance, accepts photocopied, scanned, faxed, and electronic signatures for most benefit requests, and its regulations do not require a “wet ink” original.3U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 1 Part B Chapter 2 – Signatures
Call the receiving institution before you send the letter and ask what they accept. When in doubt, sign in ink and deliver the physical document. You lose nothing by providing a handwritten signature, but you can lose time if an institution rejects an electronic one.
Notarization is a separate question. No federal law requires it for a standard authorization letter, but specific institutions and situations may demand it. Real estate transactions, court-related authorizations, and some financial institutions handling large transfers often require a notarized document. International use frequently requires notarization or an apostille. Even where it isn’t required, notarization is worth considering for high-value or legally sensitive authorizations, because a notarized letter is harder to challenge later and the fees are modest.
Mistakes That Get Letters Rejected
The IRS publishes its own list of common rejection reasons for power of attorney forms, and the same patterns show up across institutions:4Internal Revenue Service. Common Reasons for Power of Attorney POA Rejection
- A missing or undated signature. This is the single most common reason for rejection.
- Vague scope. “All banking matters” or “any necessary actions” will not survive review; name the transactions and the account numbers.
- No time limit. Open-ended authorizations make institutions nervous. Include start and end dates.
- Wrong signer. If someone signs on behalf of a business, the letter must show their title and authority to bind the organization.
- No way to verify. Without the grantor’s phone number and email, the institution cannot confirm the authorization is real.
One less obvious mistake: writing a letter so formal that the recipient can’t tell what you’re asking for. Plain language works better than legalese. “I authorize my sister, Maria Lopez, to pick up my passport renewal from the post office on January 20, 2026” is clearer, and more likely to be accepted, than a paragraph padded with “hereinafter referred to as” and “pursuant to the authority vested.”
Delivering the Letter
Match the delivery method to what’s at stake. For routine tasks, handing the letter to your representative or to the receiving institution is enough. For anything involving money, legal rights, or sensitive records, use certified mail so you have proof the letter arrived and when.
Some institutions accept emailed or faxed letters, but confirm before relying on it. Even when an electronic copy is accepted, the institution may still ask your representative to present the original in person. Attaching a copy of your government-issued photo ID, physical or electronic, can speed up verification.
Keep at least one signed copy for yourself. Give another to your representative. If the authorization covers ongoing access rather than a single transaction, both of you should know where your copies are months later.
Medical Records Need a Different Form
If you are authorizing someone to access your medical records, a standard letter will not do the job. The HIPAA Privacy Rule at 45 CFR 164.508 lays out specific content requirements that healthcare providers must follow, including a precise description of the information to be shared, who may disclose it, who may receive it, the purpose, an expiration date or event, your signature, notice of your right to revoke, and warnings written in plain language.5eCFR. Title 45 CFR Section 164.508 Most providers have their own HIPAA-compliant forms. Using the provider’s form is faster and safer than drafting your own.
Revoking an Authorization Letter
You can withdraw an authorization at any time, but the revocation has to actually reach the institution. Write a revocation letter addressed to the same recipient, state clearly that you are withdrawing the authorization, identify the original by date and subject, and name the person whose authority you are revoking. Sign and date it. Send it the way you sent the original, or by a method that gives you proof of delivery, like certified mail. Keep a copy.
Then do two more things. Tell your representative directly that their authorization is revoked. And call the receiving institution to confirm they got the revocation and updated their records. A written revocation sitting in a mailroom will not stop someone from acting on the old letter in the meantime.
For medical records, HIPAA gives you the right to revoke in writing, with the revocation taking effect when the provider receives it. It does not undo disclosures the provider already made while the authorization was active.5eCFR. Title 45 CFR Section 164.508