If during the proceedings we asked for the hearing of the witness, we must provide the Court the address of his residence. It happens that the party that wants to call a witness does not know the address. At this point, we can request the Center for Personalizing Documents of the Ministry of Interior and Administration to provide the witness’s address data. The application is subject to a fixed fee, and its recognition takes several months. Submitting the application it is necessary to prove a legal interest in obtaining a witness’s address. Unfortunately, it may be that the Personalization Center does not have a witness’s current address because it only has citizen registration data, which is often outdated.