Mailing Standards of the United States Postal Service Domestic Mail Manual > 200 Commercial Letters, Cards, Flats, and Parcels > 210 Commercial Mail Priority Mail Express > 214 Postage Payment and Documentation
1.0 Basic Standards for Postage Payment Options
Federal agency and USPS official Priority Mail Express may use the appropriate indicia, subject to 703.7.0. The mailer is responsible for proper payment of postage.
Commercial Priority Mail Express postage may be paid with: