Domestic Mail Manual > 100 Retail Mail Letters, Cards, Flats, and Parcels > 120 Retail MailPriority Mail > 124 Postage Payment Methods
1.0 Basic Standards for Postage Payment
[1-17-16] Priority Mail postage may be paid with postage stamps (see 604.1.0), with meter stamps (see 604.4.0) affixed to each piece, or with USPS Click-N-Ship.
Priority Mail Forever Prepaid Flat Rate packaging must be purchased by credit card online at www.usps.com and bears a shipping label with affixed Forever Prepaid postage. Mailers adding extra services must take packages to a retail Post Office location for payment of the associated fees for each extra service added. USPS Tracking (electronic option) is included at no additional cost.