1. In your legal system, are there acts which fall within the notion of an authentic instrument as defined in the European Union regulations?<br>[‘authentic instrument’ means a document which has been formally drawn up or registered as an authentic instrument in a Member State and the authenticity of which: <br>(I) relates to the signature and the content of the authentic instrument; and <br>(II) has been established by a public authority or other authority empowered for that purpose by the Member State of origin.]

Yes.

If so, what are they? Are these only notarial acts or also acts of other authorities?

According to Article 1216 of the Spanish Civil Code, authentic instruments are drawn up by a notary or a competent public office-holder with the formalities provided for by law.
In addition, Article 1218 of the Civil Code, with regard to the probative value of authentic instruments, establishes that they provide full proof, even before third parties, of the act or situation they document and the date on which that documentation took place. They shall also prove to the contracting parties and their heirs the declarations made by the contracting parties.

These are therefore documents issued by notaries when exercising their powers, but also by the courts, and by all public office-holders belonging to the State administration, the Autonomous Communities, the Provinces and municipal administrations.