A lockout system includes a hasp assembly and a plurality of tags. The hasp assembly has a back plate defining slots each sized and shaped to receive a tag. The back plate and tags each have openings that align when a tag is received in a slot. A first hasp portion on the back plate defines part of a closed loop. A longitudinal locking bar is slidable along the back plate and has notches shaped to receive ends of the tags. Moving the locking bar between an unlocked position and a locked position operates the second hasp portion between an open position and a closed position. In the closed position, the first and second hasp portions complete and define the closed loop, where one or more tags can be installed in slots with the first end of the tag engaging a notch to lock closed the hasp portion.