Mailing Standards of the United States Postal Service Domestic Mail Manual > 100 Retail Mail Letters, Cards, Flats, and Parcels > 170 Retail MailMedia Mail and Library Mail > 174 Postage Payment and Documentation
Overview
1.0 Postage Payment Methods for Media Mail and Library Mail
The mailer is responsible for proper postage payment. Subject to the corresponding standards, postage for Media Mail and Library Mail may be paid by postage stamps or by postage evidencing system indicia (see 604.4.0).