A mailpiece transfer apparatus uses a transfer box to unload a plurality of mailpieces from an open tray, while maintaining an orientation alignment of the flat items. The tray is placed in the transfer box, after which the transfer box, holding the tray, is rotated to cause the mailpieces to rest against a cover of the transfer box. The tray is then removed, and the transfer box rotated again, allowing the substantially flat items to rest against a bottom of the transfer box, but without the tray. The mailpieces are then guided to a next workstation. The mailpieces may be edged for delivery to the next workstation.