The short answer
A USPS Certificate of Mailing is a postmarked receipt, usually PS Form 3817, that shows the date your letter or package was handed to USPS for mailing. It costs $2.45 per piece plus postage, effective July 12, 2026, so a 1-ounce letter with a certificate costs $3.27. You can only buy it at the time of mailing, at a Post Office, and it gives no tracking or delivery record. If you need to know that the mail arrived, use Certified Mail ($5.55 plus postage) instead.
What a Certificate of Mailing proves
A Certificate of Mailing is official evidence that a specific piece of mail was presented to USPS on a specific date. You fill in your name and address and the recipient’s name and address, the retail associate postmarks the form when you hand over the mail, and the postmarked form becomes your receipt.
That is all it proves. It does not show that the mail was delivered, when it arrived, or who received it. There is no tracking number. USPS also doesn’t keep a copy, so if you lose the form, the record is gone.
People use it when the question is “did you send it, and when?” rather than “did they get it?” It costs less than Certified Mail and works with ordinary First-Class Mail letters, postcards, and large envelopes, as well as Priority Mail, Media Mail, and Library Mail.
How much a Certificate of Mailing costs
The certificate fee is charged on top of postage, per piece. These are USPS prices effective July 12, 2026; check the current USPS price list, because fees change with each price adjustment.
For one ordinary 1-ounce letter, the total is $0.82 postage plus $2.45, or $3.27. If you mail three letters together and list them on a firm mailing sheet, the certificate fees come to $2.25 in total, plus postage for each letter.
| Form | Use it for | Fee |
|---|---|---|
| PS Form 3817 | One or two individual pieces, domestic | $2.45 per piece |
| PS Form 3817 | One or two individual pieces, international | $2.55 per piece |
| PS Form 3665 (firm mailing sheet) | Three or more pieces listed with addresses | $0.75 per piece listed, minimum 3 pieces |
| Additional copy of PS Form 3817 or 3665 | A second copy of your receipt | $2.45 per page (domestic) |
| PS Form 3606-D (bulk) | Counting identical-weight pieces, without addresses | $14.00 for the first 1,000 pieces, plus $1.75 per additional 1,000 |
How to get a Certificate of Mailing
USPS issues a Certificate of Mailing only at the time of mailing. You can’t add one after the letter has gone into a collection box or your mailbox, so plan for a trip to the counter.
- Print PS Form 3817 from the USPS forms site, or ask for one at the Post Office.
- Fill in the From and To addresses in ink or type them. Make sure they match the envelope exactly.
- Put full postage on the letter, or be ready to pay it at the counter.
- Take the letter and the form to a retail Post Office counter, pay the $2.45 fee, and ask for the certificate to be postmarked.
- Keep the postmarked form with a copy of what you mailed. USPS does not keep a copy for you.
Mailing several pieces at once
PS Form 3817 is for fewer than three pieces presented at one time. For three or more, list each piece on a PS Form 3665 firm mailing sheet. If you mail fewer than 50 pieces and under 50 pounds, take the sheet to a retail Post Office; larger hardcopy mailings, and electronically submitted firm sheets, go to a Business Mail Entry Unit.
PS Form 3606-D, the Certificate of Bulk Mailing, is different. It only records how many identical-weight pieces you mailed. It does not show any addresses, so it can’t prove that a particular person was sent a particular letter.
If you live on a rural route, USPS also lets you give the mail and the certificate fee to your rural carrier. The carrier gets PS Form 3817 postmarked at the Post Office on the day of mailing and brings it back to you on the next trip.
Certificate of Mailing vs. Certified Mail
Both services can give you a postmarked record of sending when you hand the mail to a retail associate. Certified Mail also creates a tracking number, and USPS maintains a delivery record that includes the recipient’s signature. Add Return Receipt if you want that signature record sent to you. The choice depends on whether you need to show only that you mailed something or that it was delivered.
| Feature | Certificate of Mailing | Certified Mail |
|---|---|---|
| Fee (plus postage) | $2.45 (PS Form 3817) | $5.55 |
| Total for a 1-ounce letter | $3.27 | $6.37 |
| Proves the mailing date | Yes, by postmarked form | Yes, by postmarked receipt when presented at the counter |
| Tracking number | No | Yes |
| Delivery or attempt information | No | Yes |
| Recipient signature | No | USPS keeps it; Return Receipt sends it to you for $2.91 electronic or $4.65 by mail |
| Copy kept by USPS | No | USPS maintains the delivery record |
| Where to buy | At the time of mailing, at a Post Office | At a Post Office, or through an online mailing service that offers it |
Which proof of mailing should you use?
Start with the requirement, not the price. If an agency, court, contract, or landlord tells you how a document must be sent, follow that wording exactly; “mailed by” and “received by” deadlines need different evidence, and this article is not legal advice. When the instructions are silent, the choice usually comes down to the question you may later need to answer.
- “Can you show you mailed it on time?” A Certificate of Mailing is the lowest-cost postmarked record.
- “Did it arrive?” Certified Mail adds tracking and a USPS delivery record.
- “Who signed for it?” Certified Mail with Return Receipt gives you the signature record.
- “What exactly was inside?” No postal receipt shows the contents. Keep your own copy of every page you sent.
Can you get a Certificate of Mailing online?
No. USPS sells Certificates of Mailing only at the Post Office and only at the time of mailing, so no online mailing service, including IRIS, can give you a PS Form 3817. If a recipient or rule specifically asks for a Certificate of Mailing, print your letter and take it to the counter.
What IRIS can offer is different. It prints and mails your letter to a US address, and with the Certified Mail add-on ($6.95, or $10.15 in total for a one-page black-and-white letter) your private order page shows provider-reported updates and the USPS tracking number when it is available. An electronic Return Receipt can be added for $2.91. IRIS does not provide a downloadable postmarked USPS receipt or Return Receipt document, so check whether the record you need must come from the Post Office before choosing it.
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 Domestic Mail Manual 503, Extra Services (5.0 Certificates of Mailing; 3.0 Certified Mail)
- USPS Notice 123, Price List effective July 12, 2026 (Postal Explorer)
- USPS, Insurance and Extra Services
- USPS, PS Form 3817, Certificate of Mailing
Published by IRIS Postal Forms, operated by Great Lakes Computing Office LLC. Send a correction.