Certificate of Mailing service is available only at the time of mailing and provides evidence that mail has been presented to the Postal Service for mailing. Certificate of Mailing service does not provide a record of delivery, and the Postal Service does not retain copies of PS Form 3817, Certificate of Mailing, or PS Form 3877, Firm Mailing Book for Accountable Mail, or USPS-approved facsimiles. The fee paid for certificates of mailing does not insure the item against loss or damage.
At Time of Purchase
Customers may purchase a Certificate of Mailing when sending the following: Postcards, unregistered First-Class Mail International items, unregistered First-Class Package International Service, Free Matter for the Blind, unregistered Priority Mail International Flat Rate Envelopes or Small Flat Rate priced boxes, ordinary (uninsured) Priority Mail International parcels including Medium and Large Flat Rate Boxes, and Airmail M-bags.
After Mailing (Duplicate Copies)
To obtain an additional certificate after mailing, the mailer must present the original certificate and an additional certificate endorsed “Duplicate” or a copy showing the original dates of mailing. The additional certificate must be postmarked to show the current date. A Certificate of Mailing cannot be obtained in combination with Registered Mail items, insured parcels, or bulk mailings of 200 pieces or more that bear a permit imprint.