An apparatus for processing sheets of different formats, the apparatus including a feeding device that feed sheets of different formats in a feeding direction one behind the other, and at a certain conveying speed, at least two collecting drums disposed downstream of the feeding device, the at least two collecting drums having cylindrical lateral surfaces that rotate about an axis of rotation, securing means for temporarily securing the fed sheets on a circumference of the at least two collecting drums, a drive device that drives the collecting drums in rotation at a circumferential speed that corresponds to the conveying speed of the feeding device, and a sensing device for sensing the sheets of different formats moving past is arranged along the conveying path and senses the leading edge of the sheets of different formats, as seen in the feeding direction, or markings applied to the sheets of different formats.