Note: The signatures must have been made with certificates accepted by the Ministerio de Industria, Turismo y Comercio of Spain. It is possible to check the accepted certificates in the document Certificates admitted by the platform @firma. If the digital signature is not validated because the certificate is not accepted, but the certificate is among those accepted by Web page of Ministerio de Industria, Turismo y Comercio , we advise you to get in touch with the support helpdesk.