With prepaid postage, the shipping cost is paid before mailing. This postage payment method exists in various forms and each of them work somewhat differently. It's possible for senders or recipients to prepay.
This type of postage is prepaid for the sender, the recipient only pays if someone mails the envelope or postcard without a stamp. According to the U.S. Postal Service (USPS), recipients pay more than the retail cost of a stamp, plus yearly fees. They usually pay for the postage in advance.
People often mail envelopes, boxes and postcards by putting prepaid stamps on them, rather than visiting a post office. The postal service postmarks the stamps (preventing reuse) and transports the item to its destination, unless the prepaid postage is inadequate. If this problem occurs, the parcel is returned to the sender.
It's also possible to pay online and print prepaid mailing labels. Various companies offer such services, sometimes at a discount compared to normal post office rates. For example, USPS charges $1.28 less to send a five-pound Priority Mail box from coast to coast if it's prepaid online.