The short answer
Certified Mail is a USPS extra service added to a First-Class Mail or Priority Mail piece, not a separate type of postage. For a $5.55 fee on top of postage (USPS retail prices effective July 12, 2026, unchanged in the October 4, 2026 Notice 123), the sender gets a mailing receipt with a numbered record, and USPS keeps a delivery record that includes the recipient’s signature. It doesn’t speed the letter up or insure what’s inside; it creates evidence that a specific piece was sent and delivered, or that delivery was attempted.
What Certified Mail means
Certified Mail is a numbered extra service. The Domestic Mail Manual says it gives the sender a mailing receipt and, on request, electronic verification that the piece was delivered or that a delivery attempt was made. USPS also keeps its own record of delivery, which includes the recipient’s signature.
You can add it only to First-Class Mail or Priority Mail. A certified letter is dispatched and handled in transit as ordinary mail, so it travels at the speed of the mail class it rides on. It can go to US addresses, including APO, FPO, and DPO addresses and US territories, but USPS doesn’t offer Certified Mail for international mail.
That is the whole point of the service: a record. When someone sends a certified letter, they’re usually planning to show later that a particular piece of mail reached a particular address on a particular date.
What the sender gets from Certified Mail
Certified Mail creates several separate records. Only the mailing receipt is guaranteed to be in the sender’s hands; a copy of the signature costs extra.
USPS’s Certified Mail guidebook says the delivery record is kept for two years from the date of mailing, and that records older than 60 days take longer to retrieve. A Return Receipt must be bought at the time of mailing; it can’t be added afterward.
| Record | What it shows | Cost |
|---|---|---|
| Mailing receipt (PS Form 3800) | The article number; if a clerk accepts the letter, a postmark showing the date USPS took it | Included in the $5.55 fee |
| Delivery status | Delivery or attempted delivery, looked up by article number on usps.com or by phone | Included |
| USPS delivery record | Delivery details including the recipient’s signature, held by USPS | Included |
| Return Receipt, electronic | A proof-of-delivery letter with the signature, sent by email | $2.91 |
| Return Receipt, hardcopy (PS Form 3811) | The signed green card, mailed back to the sender | $4.65 |
What Certified Mail does not do
People often expect more from Certified Mail than USPS promises. It doesn’t do any of the following:
- Speed up delivery. A certified First-Class letter moves at First-Class Mail speed.
- Insure the contents. Certified Mail has no insurance of its own, and USPS doesn’t let you buy additional insurance on a Certified Mail item. Priority Mail keeps its included insurance of up to $100 when Certified Mail is added.
- Prove what was inside. The receipt and delivery record identify a numbered piece of mail, not the pages in it, so the sender should keep an exact copy.
- Guarantee a refund. USPS may refund the Certified Mail fee in limited cases, such as non-delivery caused by USPS, but not when delivery was attempted and the letter went unclaimed.
What does Certified Mail look like?
A certified letter carries a green Certified Mail label, the barcoded part of PS Form 3800, above the delivery address and to the right of the return address. USPS requires the banner text CERTIFIED MAIL or USPS CERTIFIED MAIL above the barcode, including on the barcoded labels some business mailers print themselves.
Other markings tell you what the sender paid for. “Return Receipt Requested” near the Certified Mail endorsement means a green card (PS Form 3811) is usually attached to the back of a small envelope. “Restricted Delivery” above the address means only the named person or their authorized agent may sign for it.
When the carrier offers it to you, you sign and legibly print your name before the letter is handed over, and you may be asked for ID. Before you sign, you may ask to see the sender’s name and address.
Why would I get Certified Mail, and who sends it?
Certified Mail is rarely random. Someone paid extra because they may need to show that the letter reached you. USPS’s own guidebook lists the most common uses:
- Legal notices
- Government documents
- Debt collection letters
- Foreclosure notices
- Health care records
Why would the IRS send a certified letter?
Federal tax law names Certified Mail for some IRS notices. The IRS may send a statutory notice of deficiency, the letter that proposes additional tax and opens your right to go to the U.S. Tax Court, by certified or registered mail. It also uses certified or registered mail, when the notice isn’t delivered in person, for a final notice of intent to levy, such as an LT11 or Letter 1058, and for notice that a federal tax lien was filed.
Don’t ignore one. A deficiency notice mailed to your last known address is legally sufficient, and the Tax Court petition period, generally 90 days, runs from the date it was mailed. The letter itself gives the exact deadline.
Look up the notice number, printed in the corner of the letter, on IRS.gov. If it doesn’t appear there or looks suspicious, the IRS says to call 800-829-1040.
What happens when no one signs for Certified Mail?
If nobody is available to sign, the carrier leaves a notice, PS Form 3849, and the letter goes back to the Post Office. USPS holds Certified Mail there for 15 days and returns it to the sender on the 16th day, unless the sender marked fewer days on the piece. Within that window you can pick it up or schedule a redelivery online with the barcode on the notice or the tracking number. Signing the notice and leaving it out doesn’t count: someone must sign at delivery.
You can also refuse a certified letter when the carrier offers it, and it goes back to the sender. Once you’ve accepted it, you can’t mark it Refused and return it for free. Refusing or ignoring the letter doesn’t make the underlying matter go away: for an IRS deficiency notice, as noted above, the deadline runs from the date it was mailed.
How much Certified Mail costs and how to send it
The Certified Mail fee is $5.55 plus postage, so a 1-ounce letter with a Forever stamp costs $6.37 (USPS retail prices effective July 12, 2026, unchanged in the October 4, 2026 Notice 123). An electronic Return Receipt adds $2.91 and the hardcopy green card adds $4.65. The full price breakdown, with Restricted Delivery, is in the cost guide.
To send one, fill out PS Form 3800 with the recipient’s name and address, attach the green label, and hand the letter to a Post Office clerk so the receipt is postmarked. You can also send a certified letter online without visiting the Post Office. The forms guide covers every field on PS Forms 3800 and 3811.
What IRIS does and doesn’t do for Certified Mail
IRIS prints a letter from the US Letter-size PDF you upload and mails it by USPS First-Class Mail to a US address. Certified Mail adds $6.95 to the letter price of $3.00 plus $0.20 per black-and-white page or $0.40 per color page, so a one-page black-and-white certified letter costs $10.15. An electronic Return Receipt adds $2.91 and is available only with Certified Mail. Certified letters can be up to six sheets (6 single-sided or 12 double-sided pages), and you review the document, addresses, options, and total before paying.
IRIS doesn’t offer Priority Mail, Registered Mail, Restricted Delivery, or the hardcopy green-card Return Receipt, and it can’t enclose originals, checks, or anything you hold on paper; it prints your PDF. It doesn’t guarantee a delivery date, and payment or order status is not proof of delivery. If an agency needs an original signature or another submission method, follow its instructions.
Sources & further reading
Product details checked against the IRIS API contract when this article was published. Platform references can change; consult the linked documentation when implementing.
- USPS FAQ: Certified Mail – The Basics
- USPS Domestic Mail Manual 503: Extra Services (1.8 delivery records; 3.0 Certified Mail; 8.0 Signature Services)
- USPS Domestic Mail Manual 508: Recipient Services (1.1 refusal and accountable mail delivery)
- USPS Notice 123 price list (Postal Explorer)
- USPS: Insurance and Extra Services
- USPS PostalPro: Certified Mail Guidebook (PDF, May 2024)
- USPS FAQ: Return Receipt – The Basics
- USPS FAQ: Redelivery – The Basics
- IRS: Understanding your IRS notice or letter
- IRS: Understanding your Letter 3219B (Statutory Notice of Deficiency)
- IRS: Understanding your LT11 notice or Letter 1058
- Internal Revenue Manual 5.11.1: Notice of Intent to Levy
- 26 U.S.C. 6212: Notice of deficiency
- 26 U.S.C. 6331: Levy and distraint
Published by IRIS Postal Forms, operated by Great Lakes Computing Office LLC. Send a correction.