It is necessary to have a certificate recognised by the Administration. For example, certificates issued by certification authorities from other countries are not valid.

Additionally, the certificate must be valid, that is, it must not be expired or revoked. The expiry of the certificate can be checked directly by the user (the expiry date appears on the certificate itself), however, the revocation status cannot.

A certification authority automatically revokes a certificate when a new one is generated for the same person. In the case of public employee certificates, if the person holds a position that is reflected in the certificate (e.g. department director, rector, etc.), the General Secretariat revokes the certificate of the person who leaves the position (It should be verified whether this is something the General Secretariat does automatically)

The validity of a certificate can be checked at:

https://valide.redsara.es/valide/validarCertificado/ejecutar.html

If the user is teaching staff or PTGAS of the UPM, it is necessary to verify whether they need a certificate for a natural person or as a public employee. In the latter case, they should contact the General Secretariat for instructions on how to apply.

You can request a free electronic certificate for a natural person from the FNMT https://www.sede.fnmt.gob.es/certificados/persona-fisica

One of the steps to obtain the certificate is identity verification at an authorised office http://mapaoficinascert.appspot.com/. Please note that these offices may require an appointment. One of these offices, where no appointment is necessary, is the UPM General Registry, c/Ramiro de Maeztu nº7, open from 9:00 to 14:00.

If you do not wish to travel to an office for identity verification, the FNMT allows this to be done by video call, but there is a cost involved.