Abstract: A convertible envelope is adapted to be used as a shipping container and then converted to a carrying bag. The envelope has a foldable bag with an open top, front and back panels and closed side and bottom edges. The bag is intended to be shipped in folded configuration and held therein by releasable securements. The open top is covered by a top flap which has one edge portion removably secured to either the front panel or the back panel and another edge portion which carries adhesive for sealing the envelope. The envelope can have a draw string and grommets for use as a back pack or handles for use as a tote bag.