The EPO has the power to require the filing of a certificate, certifying that a translation supplied corresponds to the original text, within a period to be determined by it. The exercise of this power should be determined on a case-by-case basis and ought to be used only when the official concerned has serious doubts as to the accuracy of the translation. The certificate could be called for either from the person who made the translation or from some other competent person. Failure to file the certificate in due time will lead to the document being deemed not to have been received unless the EPC provides otherwise. This partial loss of rights is subject to further processing under Art. 121 and Rule 135.