Certificate of mailing affidavit

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

• 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.

• 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).