adj. paid in advance (used especially of mail items)
adj. paid after the service (used especially of cellular phones)
the GNU version of the Collaborative International Dictionary of English
adj. Having the postage prepaid, as a letter.
The Century Dictionary and Cyclopedia
Having the postage prepaid: as, a post-paid letter.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. having the postage paid by the sender
adj. used especially of mail; paid in advance
Word Usage
"Although AT&T is touting its lead in postpaid smartphone subscribers, the carrier is just now taking steps to gain a better foothold in the prepaid market, an area where rivals have a head start."