Bisects and splits refer to postage stamps that have been cut in part, most commonly in half, but also other fractions, and postally used for the proportionate value of the entire stamp, such as a two cent stamp cut in half and used as a one cent stamp. When stocks of a certain stamp ran out, postmasters sometimes resorted to cutting higher denominated stamps in half, vertically or diagonally, thus obtaining two ''stamps'' each representing half of the original monetary value, or ''face'' value, of the uncut stamp. The general public also resorted to this practice, sometimes pursuant to official or tacit permission and sometimes without any express authorization.

can i cut a postage stamp in half?
yes