The bank stamp for verification that transfer agents require on securities paperwork is called a Medallion Signature Guarantee. You get one in person at a bank, credit union, or brokerage where you already hold an account, by bringing government-issued photo ID, a recent account statement, and the unsigned transfer document. The stamp is a warranty from the financial institution that you are who you say you are and are authorized to make the transaction, and the institution takes on financial liability if the signature turns out to be forged. That assumption of risk is why transfer agents insist on this stamp instead of accepting a notary’s seal.
How a Medallion Guarantee Differs From a Notarization
A notary public confirms that someone signed a document in the notary’s presence and has no financial exposure if the signer is an imposter. A bank that applies a Medallion stamp is on the hook. If the transaction turns out to be fraudulent, the guaranteeing institution is liable for losses up to the stamp’s coverage limit through the Medallion program’s indemnity agreement.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities Federal rules at 17 CFR 240.17Ad-15 govern which institutions may issue the guarantee and how transfer agents must handle it.2eCFR. 17 CFR 240.17Ad-15 – Signature Guarantees
When You Need One
You’ll need the stamp whenever securities change hands or accounts. Typical triggers include transferring stock or bond certificates into a brokerage account, moving investments between firms, re-registering securities after a name change, and requesting physical certificates for shares held electronically. Any change of ownership involving securities almost always requires it.
The Medallion Guarantee is specifically for securities transactions. It is not used for address changes, account number updates, or other administrative tasks. A separate program, the Signature Validation Program, covers non-securities commercial paperwork such as loan applications, changes to certificates of deposit, and trust amendments. The two are not interchangeable, so asking for a Medallion stamp on a non-securities form, or a Signature Validation on a stock transfer, will get you turned away.
Where to Get One
The federal regulation recognizes five categories of eligible guarantors: banks, broker-dealers, credit unions, national securities exchanges and clearing agencies, and savings associations.2eCFR. 17 CFR 240.17Ad-15 – Signature Guarantees In practice, commercial banks, credit unions, and brokerage firms are where most people get their stamps.
The catch: most institutions provide the stamp only to their own customers. The SEC states directly that if you are not a customer of a participating financial institution, it is unlikely the institution will guarantee your signature.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities The SEC recommends starting with a bank, savings association, brokerage firm, or credit union where you already do business.
Fees range from nothing to about $100. Many banks and brokerages waive the charge for established customers. Non-customers who find a willing institution can expect to pay in the $10 to $100 range, and some institutions factor in the value of the transaction. Ask about the fee when you schedule the appointment.
What to Bring
Walking in without the right paperwork is the most common reason people leave empty-handed. Gather all of it before you go:
- Government-issued photo ID such as a valid passport or driver’s license.3Bank of America. Requesting a Medallion Signature Guarantee
- A recent account statement showing ownership, the account number, and the value of the securities. Most institutions require a statement dated within the last six months.3Bank of America. Requesting a Medallion Signature Guarantee
- The unsigned document. The stock power form, transfer request, or other paperwork must stay completely unsigned until you are sitting in front of the bank officer. A pre-signed document will be rejected.4eCFR. 31 CFR 306.45 – Certifying Individuals
- Transfer instructions from the receiving brokerage or transfer agent, so the officer understands what is being requested.
- A statement from the receiving firm if one is required, typically dated within 90 days.
You can fill in the informational fields ahead of time: legal name, account numbers, share counts, and dollar amounts. Copy those figures from your most recent statement so they match the bank’s records exactly. Leave only the signature line blank.
What Happens at the Appointment
The stamp must be applied in person. No bank offers a fully remote or online version, because the whole point is that a trained officer watches you sign and personally verifies your identity.5Bank of America. Medallion Signature Guarantee The stamp is restricted to designated officers, not general tellers, so calling ahead for an appointment is standard.
During the meeting, the officer reviews your ID, verifies your account information, and watches you sign. The officer then applies the physical stamp, adds their own identifying information, and logs the transaction internally.6Insured Retirement Institute. Medallion Signature Guarantee Best Practices
Once stamped, the document is active and ready to send. A Medallion Guarantee does not technically expire, but it is intended for immediate use. If you wait months to submit it, the receiving firm may require a new one, and higher-value transactions tend to face stricter time limits.
Coverage Limits You Should Know Before You Go
Not all Medallion stamps are equal. Each stamp carries a letter prefix indicating the maximum dollar value it covers, and if your transaction exceeds that limit the transfer agent will reject the stamp.7Computershare. What Is a Medallion Guarantee This is why the bank asks for the estimated value before stamping. The common tiers:
- D: up to $250,000
- C: up to $500,000
- B: up to $750,000
- A: up to $1,000,000
- X: up to $2,000,000
- Y: up to $5,000,000
- Z: up to $10,000,000
Your bank’s surety bond determines which prefix levels it can issue. A small credit union may only be authorized for the lowest tiers, while a major commercial bank can typically handle higher amounts. If your transaction exceeds what your institution can stamp, you will need to find a different provider with a higher authorization level.
Why Banks Sometimes Refuse
Banks take the process seriously because their own money is at risk. The most frequent reasons for denial:
- Incomplete or incorrect documents, an expired ID, or a mismatch between the name on your ID and the name on the document.
- A transaction value that exceeds the institution’s surety bond limit.
- Anything irregular about the request, such as conflicting instructions, unclear beneficiaries, or documents that don’t match.
- No designated space on the document itself for the stamp. If there is nowhere to place it properly, the receiving institution may reject it.
- Signing in a representative capacity — as trustee, executor, or agent under a power of attorney — without documentation proving your authority.
A denial isn’t necessarily permanent. Fix the issue and come back. But the bank’s legal counsel has the final say, and no institution is obligated to approve a request it isn’t comfortable with.
Estate Transfers and Power of Attorney
Transferring a deceased person’s securities is one of the most common complicated cases. Along with the standard documents, you’ll need a certified copy of the death certificate and court-issued documents appointing you as the estate’s personal representative, executor, or administrator. A will alone isn’t sufficient; court appointment documents are required.5Bank of America. Medallion Signature Guarantee
Those court documents have their own shelf life. Letters testamentary generally must be dated within 60 days of original issuance. New York extends this to six months.5Bank of America. Medallion Signature Guarantee If yours are older than the allowed window, you’ll need to return to the court for a fresh set. Some states also allow a small estate affidavit instead of formal probate, though availability and requirements vary by state.
If you hold a power of attorney and need to sign on behalf of the account owner, bring the original or a certified copy of the POA along with your own photo ID. The officer will review it to confirm it grants authority over financial transactions. Expect a longer appointment, because compliance review is more involved when someone signs in a representative capacity.
If No Institution Will Stamp for You
If your own bank turns you down, try other participating institutions where you already hold accounts, whether that’s a brokerage, a credit union, or another bank. If you have exhausted your options, contact the transfer agent or brokerage requiring the stamp and explain the situation. Some transfer agents, including Computershare, operate their own Medallion waiver programs for certain transactions.7Computershare. What Is a Medallion Guarantee These alternatives typically involve additional identity verification and may carry a separate fee. Transfer agents may also accept other safeguards for lower-risk transactions, such as sending redemption proceeds only to the address on file or verifying by phone. The workarounds aren’t guaranteed, but transfer agents have more flexibility than most people realize.