A document processing apparatus processes an encoded document, which is a medium on which a machine readable code comprising a code of an encoded electronic document is formed. The document processing apparatus includes an acquiring unit, an editing-information managing unit and a decoding process unit. The acquiring unit acquires the machine readable code read from the encoded document. The editing-information managing unit manages editing information of the electronic document, which is an original document of the encoded document. The decoding process unit decodes the acquired machine readable code on a basis of the editing information.