The invention relates to an apparatus and a method for processing value documents. A value document is input to the input opening of an apparatus for value-document processing and transported using a transport system of the apparatus to an image sensor which senses a partial image of the value document. A contour of the front partial area is ascertained from the sensed partial image and checked. If the check of the contour of the front partial area yields a fault, the value document is rejected. Faulty or faultily transported value documents can thus be recognized and transported back to the input opening at a very early time.