DMM TOC > 200 Commercial Mail Letters, Cards, Flats and Parcels > 270 Media Mail and Library Mail|
The mailer is responsible for proper postage payment. Mail manifested using the Electronic Verification System (eVS) under 705.2.9 must be paid with a permit imprint. Postage for Media Mail and Library Mail may be paid by any method (see 604) except precanceled stamps. Pieces with postage affixed must bear the correct numerical value of postage for which the piece qualifies. Permit imprint may be used for mailings of nonidentical-weight pieces only if authorized by Business Mailer Support at USPS Headquarters.