A USPS Certificate of Mailing is a postmarked receipt proving you handed a specific piece of mail to the Postal Service on a specific date — and that is the entire extent of what it does. It costs a few dollars, you fill out PS Form 3817 at the counter, and you walk out with the only copy that will ever exist. It doesn’t track your item, confirm delivery, or insure anything. If you need proof your mail arrived, you need Certified Mail instead — and that distinction is where most people get tripped up.
Key Takeaways
- It proves the date you mailed something — nothing more. USPS’s manual states it “does not provide a record of delivery.”
- You can only buy it at a Post Office counter, at the moment you mail the item. There’s no online option and no way to add it afterward — once the mail is gone, the window has closed.
- PS Form 3817 covers a single piece; a firm sheet covers three or more. USPS’s consumer page names PS Form 3877 for multiples, the Domestic Mail Manual names PS Form 3665 — the clerk will hand you the right one.
- USPS keeps no copy. The postmarked form you carry out is the record. Lose it and there’s nothing to look up.
- It’s one of the cheapest add-ons USPS sells — well under Certified Mail — making it the right tool for deadline-sensitive letters where you only need to prove you sent it on time.
What Is a USPS Certificate of Mailing?
A Certificate of Mailing is an extra service from the United States Postal Service that gives you a dated, postmarked receipt for a particular piece of mail. USPS calls it an official record establishing the date your mail was presented for mailing.
The form is refreshingly blunt about its own scope. Printed across the top of PS Form 3817 is one sentence: “This Certificate of Mailing provides evidence that mail has been presented to USPS for mailing.” Below it are address lines for sender and recipient, a box marked “To pay fee, affix stamps or meter postage here,” and a space marked “Postmark Here.” That’s the whole document — a sender, a recipient, a fee, and a date stamp.
The postmark is what makes it useful: a round-dated Postal Service stamp on an official form is evidence of a mailing date in a way your own calendar entry is not, which is why it turns up wherever a rule says a document counts when it’s postmarked rather than when it’s received.
Per the Domestic Mail Manual, it’s available with First-Class Mail, Priority Mail, Media Mail, Library Mail, and Bound Printed Matter. The International Mail Manual also allows it for postcards, unregistered First-Class Mail International, unregistered First-Class Package International Service, and airmail M-bags — but never with Registered Mail, insured parcels, or permit imprint postage.
How Much Does a Certificate of Mailing Cost?
A few dollars — one of the cheapest add-ons USPS sells, and materially less than Certified Mail. The fee sits on top of your postage rather than replacing it, so a letter costs a First-Class stamp plus the certificate fee.
The fee differs slightly between an individual article and a piece listed in a firm mailing book, which is priced per piece and works out cheaper on a stack. USPS also adjusts extra-service fees periodically, so any figure quoted in a blog post has a short shelf life. For the current number, check USPS Notice 123, the official Price List, or the USPS extra services page, which shows it alongside Certified Mail and Return Receipt.
How Do You Get a Certificate of Mailing?
At a Post Office retail counter, and only at the time of mailing. This is the rule that catches people out: you cannot buy a Certificate of Mailing online, and you cannot buy one after your mail has left your hands. The Domestic Mail Manual specifies it must be presented only at the time of mailing. Drop the envelope in a blue collection box and the opportunity is gone.
- Bring the sealed, addressed mailpiece to the counter — don’t mail it first and ask afterward.
- Fill in the From and To lines on PS Form 3817 exactly as they appear on the envelope. Blank forms sit in the lobby at most branches, so you can do this before queuing.
- Pay the fee — affix stamps or meter postage in the marked box, or have the clerk ring it up with your postage.
- The clerk round-dates the form with the office postmark and hands it back. That’s your receipt.
- File it somewhere you’ll find it again — this is the only copy in existence.
PS Form 3817 vs. the Firm Sheet (Form 3665 / Form 3877)
PS Form 3817 is the single-piece version, used for fewer than three pieces presented at one time at a retail Post Office. For three or more you use a firm sheet — one itemized list of every recipient, given a single postmark covering the whole batch. That’s how law offices and property managers handle notice mailings without filling out twenty separate 3817s.
One genuine wrinkle before you go hunting for a form number: USPS’s own sources name two different forms. The consumer-facing extra services page tells customers to complete “PS Form 3817 or PS Form 3877,” while the Domestic Mail Manual and PostalPro both name PS Form 3665, “Certificate of Mailing — Firm.” The distinction: 3665 is the firm sheet for Certificate of Mailing, while PS Form 3877, the Firm Mailing Book for Accountable Mail, lists pieces of accountable mail — Certified, Registered, insured, COD, Priority Mail Express. Ask the clerk for a Certificate of Mailing for however many pieces you have and you’ll get the right one.
Does a Certificate of Mailing Provide Tracking or Proof of Delivery?
No — to all of it. There’s no tracking number, no scan events, no delivery confirmation, no signature, and no insurance. The Domestic Mail Manual states it “does not provide a record of delivery,” and the International Mail Manual adds that it “does not insure the item against loss or damage.”
There’s also no backup copy. USPS retains no copies of PS Form 3817 or the firm sheet, so nothing about your certificate exists in a Postal Service database — unlike every tracked service, where USPS holds the scan history regardless.
If you need to know something actually arrived, you’re shopping for a different product:
- Need to know it arrived? Any tracked service will tell you — see our guide to USPS proof of delivery for how to obtain and document a delivery record.
- Need a signature on file? That’s Certified Mail territory.
- Need the recipient’s signature returned to you? Add a Return Receipt to Certified Mail — the upgrade that turns “it was delivered” into “here is who signed for it.”
- Need the item insured and secured in transit? Registered Mail, a separate and more involved service.
Certificate of Mailing vs. Certified Mail — Which Do You Need?
These two get confused constantly because both are sold as “proof,” but they cover opposite ends of the journey. A Certificate of Mailing proves departure. Certified Mail proves arrival.
| Certificate of Mailing | Certified Mail | |
|---|---|---|
| What it proves | You mailed it, on this date | It was delivered, with a signature on record |
| Tracking number | No | Yes |
| Proof of delivery | No | Yes |
| Signature | No | Yes, retained by USPS |
| USPS keeps a copy | No — your form is the only record | Yes, delivery record retained |
| Where to buy | Post Office counter only, at time of mailing | Post Office counter or online |
| Relative cost | Lowest — a few dollars | Several times higher |
The decision rule is short. If you need delivery proof, send Certified Mail — our walkthrough on how to send Certified Mail covers the green card, the electronic return receipt option, and what the signature record gets you. If you only need to show a document left your hands before a deadline, the Certificate of Mailing does that for far less.
One caution: read the requirement first. Plenty of contracts and state statutes specify “certified mail, return receipt requested” by name, and a Certificate of Mailing does not satisfy that no matter how good your postmark is. If Registered Mail is also on the table, our comparison of Certified Mail vs. Registered Mail covers the security and liability differences.
When Should You Use a Certificate of Mailing?
It earns its keep on one shape of problem: the deadline is what matters, and the recipient’s cooperation isn’t guaranteed.
- Deadline-governed filings, where a rule says the postmark date controls — tax documents, regulatory submissions, appeal notices.
- Contract cancellations and lease notices. A lease requiring 30 days’ written notice is satisfied by the date you sent it, and a landlord who claims nothing arrived is met with a postmarked form.
- Insurance claims and policy correspondence, where timeliness is frequently the entire dispute.
- High-volume batch notices. An HOA sending 200 assessment letters gets all of them onto one postmarked firm sheet for a fraction of the Certified Mail cost.
- Mail the recipient might refuse. Certified Mail can be declined at the door, and a refused piece proves nothing about your compliance. A Certificate of Mailing can’t be refused — which is why many attorneys send both.
Where it’s the wrong tool: valuables, anything you’d file a loss claim on, and packages generally. If you’re shipping a parcel through a platform like ParcelPath, the discounted USPS and UPS labels come with tracking built in, which already answers the “did it get there” question a Certificate of Mailing cannot.
How Long Should You Keep the Certificate?
Longer than you think, because there’s no way to get another one — USPS retains no copies, so the postmarked form is a single point of failure. Scan it the day you get it, then keep the paper original stapled to a copy of what you mailed — a postmark proving you sent an envelope is much weaker than one attached to the document it carried. Match retention to the underlying deadline: as long as the statute of limitations or dispute window it protects, often years rather than months. Duplicates are available after mailing, but the Domestic Mail Manual requires the original postmarked certificate to get one.
Sources
- USPS Domestic Mail Manual 503 — Extra Services, Section 5.0 Certificate of Mailing
- USPS International Mail Manual, Chapter 3 — Extra Services
- USPS PS Form 3817, Certificate of Mailing (PDF)
- USPS — Insurance & Extra Services
- USPS PostalPro — Certificate of Mailing
- USPS Notice 123 — Price List
Frequently Asked Questions
What is a USPS Certificate of Mailing?
It’s a postmarked receipt from USPS proving you presented a specific piece of mail on a specific date. The form states it “provides evidence that mail has been presented to USPS for mailing.” It establishes the mailing date only — not tracking, not insurance, not proof of delivery.
How much does a USPS Certificate of Mailing cost?
A few dollars — one of the cheapest extra services USPS sells, and considerably less than Certified Mail. The fee is charged on top of postage and differs slightly between an individual article and a piece listed in a firm mailing book. Check USPS Notice 123, the official Price List, for the current fee.
Can I get a Certificate of Mailing online or after I’ve already mailed something?
No to both. USPS sells it only at a Post Office retail counter, and the Domestic Mail Manual specifies it must be presented only at the time of mailing. Once your mail has been dropped in a collection box or handed over without the form, a certificate can no longer be issued for it.
What is the difference between PS Form 3817, PS Form 3665, and PS Form 3877?
PS Form 3817 covers a single piece. For three or more mailed at once, USPS’s Domestic Mail Manual names PS Form 3665, the “Certificate of Mailing — Firm” sheet, while USPS’s consumer-facing extra services page refers customers to PS Form 3877 — technically the Firm Mailing Book for Accountable Mail, used for Certified, Registered, insured, COD, or Priority Mail Express. Ask the clerk for a Certificate of Mailing for the number of pieces you have and you’ll get the correct form.
Does a Certificate of Mailing prove my letter was delivered?
No. The Domestic Mail Manual is explicit that it “does not provide a record of delivery,” and it includes no tracking number, no delivery scan, and no signature. If you need evidence your mail arrived, use a tracked service such as Certified Mail, optionally with a Return Receipt to capture the recipient’s signature.
What happens if I lose my Certificate of Mailing?
The proof is gone. USPS retains no copies, so there’s no record to look up and no way to reissue it. Duplicates are available only by presenting the original postmarked certificate — so scan the form the day you receive it and store the original with a copy of what you mailed.
Part of our USPS shipping guide. Related: How to Send Certified Mail · Certified Mail vs. Registered Mail · USPS Return Receipt · USPS Proof of Delivery.
