The Joint Committee for the European Union of the Spanish Parliament (in Spanish: Comisión Mixta Congreso de los Diputados – Senado para la Unión Europea) carries out the subsidiarity scrutiny of EU draft legislative acts.

When the Spanish Parliament receives the communication on the commencement of the eight-week period, it transfers the EU draft legislative act to the regional Parliaments, without any filtering procedure. Should the Joint Committee draft a reasoned opinion, it must include an account of the regional opinions. Nevertheless, there is no legal obligation for the national Parliament to take into account regional opinions when drafting the national reasoned opinion.

Most Autonomous Communities, via their Regional Parliaments, conduct subsidiarity scrutiny procedures at regional level. Nevertheless, the scrutiny may also take place within the broader context of scrutiny of EU acts in some Autonomous Communities.