(1) (Electronic-STAMP) One of several terms used to refer to the U.S. Postal Service's IBIP program. See PC Postage.

(2) (E-Stamp Corporation) In 1999, E-Stamp was the first PC Postage service approved by the U.S. Postal Service, but phased out of the business in late 2000. E-Stamp's postage system used a hardware key that acted as a vault to store paid postage so that stamps could be printed offline. E-Stamp's "e-stamp" trademark was later acquired by Stamps.com. See PC Postage and Stamps.com.