An edge justification device for a mail processing machine. The device shifts the mailpiece from bottom edge justified to top edge justified. The amount of shift is determined as a function of the height of the mail piece. One embodiment solves the problem of switching from bottom to top registration by having a series of steerable nips, which are arranged in line, parallel to the mail flow direction. As the mail piece travels though the justifier, the nips will rotate to impart a lateral velocity to the mail piece, shifting it over to properly justify it. In a further embodiment, the nips of the justification device are not steerable. Rather, a whole nip assembly that is transporting the mail piece is moved laterally to switch from bottom to top justification.