The decree on the detailed rules of the voluntary register of works kept at the Hungarian Patent Office came into force in 2006. The entry into the voluntary registry of works can be requested in the case of works under copyright legislation, including the performances of related rights. Copyright protection comes into force automatically when the work is created. Therefore the author may find it difficult to prove his authorship or the time of creation as well as the original content and form of the work at a later date. The certification of the entry into the voluntary register of works, issued by the HPO, may provide a solution in such situations. This certification is an official certificate which must be acknowledged by all parties until its invalidity is proved. The issuing of the certificate does not imply new copyright or related rights. It only proves that the author entered the work in question - a copy of which or the work itself being attached to the certificate - into the voluntary register as his own work. It also proves that, at the time of issuing the certificate, the work in question existed in the form and with the content as it can be stated in the attachment. This certificate can be used in legal cases concerning authorship, copyright protection, copyright infringement and also in other cases, e.g. litigation related to the infringement of personal rights. This paper provides detailed information on the process of the entry into the voluntary register of works.