Instructions for Certificate of Mailing — Firm
This service provides evidence that the mailer has presented individual items to the Postal Service™ for mailing, and is available for the following products:
¡¡ Domestic services: First-Class Mail®, First-Class Package Service®, Priority Mail®, Media Mail®, Library Mail, Bound Printed Matter, Merchandise Return Service, Parcel Return Service, and USPS Retail Ground™.
¡¡ International services: First-Class Mail International® (unregistered items), First-Class Package International Service® (unregistered items), Free Matter for the Blind, and Airmail M-bags®.
The following instructions are for the preparation and use of PS Form 3665, Certificate of Mailing – Firm (including USPS-approved facsimiles):
1.Complete and print all forms in ink or ball point pen.
2.Enter the name and address of the sender at the top of the form.
3.Enter a complete return address on each article.
4.Ensure the articles are properly packaged.
5.In the appropriate column, enter the applicable postage and fees.
6.Insert a firm-specific identifier or account number if desired. (This number is for the sender’s use only, and the Postal Service will not use it for identification.)
7.When describing and listing three or more individual pieces but not presenting the pieces in the order shown on the sheet, consecutively number each entry line on the sheet and number each piece to show both the corresponding sheet and line number.
8.Enter the total number of articles in the proper space at the top of the form.
9.Obliterate all unused portions of the “Address” column by drawing a diagonal line through the unused portion on the form.
10.When the number of articles presented exceeds the allotted space on the form, use multiple sheets, and in the provided blank spaces in the lower left of the form, number them consecutively to show sheet number and total number of sheets (such as “Page 1 of 4,” “Page 2 of 4,” etc.).
11.Present PS Form 3665 and the mailing as follows:
¡¡ 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).
Privately Printed Forms: The Postal Service allows mailers to use USPS-approved privately printed or computer-generated firm sheets that are nearly identical in design elements and color to the USPS-provided PS Form 3665. See DMM 503 for details on the approval process.
The mailer must retain the original written approval granted by the Postal Service as evidence that the privately printed facsimile of PS Form 3665 has been approved by the Postal Service. The Postal Service does not retain records on the facsimile approvals. A mailer using privately prepared forms must periodically verify them against the USPS‑provided version and, if necessary, make routine updates and obtain approval of the updated facsimile form.
A mailer using an approved privately printed form and wanting the form sheets postmarked by the Postal Service must present the forms with the articles to be mailed at a Post Office facility. The forms become the mailer’s only receipt (the Postal service does not retain a copy).