Getting Evidence You Sent It

Certificate of Mailing

PS Form 3817

Do you need evidence to show that your letter or package was mailed? Use a Certificate of Mailing.

Certificate of Mailing service provides a postmarked mailing receipt as evidence that your item was mailed.

This is all you need to do:

• Complete PS Form 3817 at the time of mailing.
• Pay the applicable extra service fee.

Additional information:

• Available for Priority Mail, First-Class Mail, USPS Retail Ground, Media Mail, Library Mail, Bound Printed Matter*, unregistered Priority Mail International Flat Rate Envelopes and Small Flat Rate Boxes, unregistered First-Class Mail International items, unregistered First-Class Package International Service items, and Airmail M-Bags.

Other options:

• PS Form 3606-D, Certificate of Bulk Mailing — Domestic, which can be used for domestic mailings of identical-weight pieces.
• PS Form 3606, Certificate of Bulk Mailing — International, which can be used for international mailings of identical-weight pieces.
• PS Form 3665, Certificate of Mailing — Firm (Domestic), which can be used for three or more pieces that include the sender’s address and the return address of each item listed.
• PS Form 3877, Firm Mailing Book for Accountable Mail, which can be used for international mail when mailing three or more individual pieces.

Note: When requesting a Certificate of Mailing for three or more pieces presented at one time, you may use PS Form 3665 or a currently USPS-approved facsimile, including computer-generated firm sheets. The following processes are the appropriate ways to present PS Form 3665 or facsimile with a mailing at a USPS facility:

• When the mailing has fewer than 50 mailpieces and less than 50 pounds, present the form and mailing at a retail Post Office location.
• When the mailing has at least 50 mailpieces or at least 50 pounds, present the form and mailing at a business mail entry unit (BMEU) or USPS-authorized detached mail unit (DMU).