The requirements for access to the master's degree are those established in article 18 of Royal Decree 822/2021, of September 29, which establishes the organization of university education and the quality assurance procedure.
Possession of an official Spanish Graduate or Graduate university degree or equivalent is a condition for accessing a Master's Degree, or, where appropriate, having another University Master's degree, or titles of the same level as the Spanish Bachelor's or Master's degree issued by universities and higher education institutions in an EHEA country that in that country allow access to Master's degrees.
In the same way, people in possession of titles from educational systems that are not part of the EHEA, which are equivalent to a Bachelor's degree, will be able to access a Master's Degree in the Spanish university system, without the need for homologation of the title, but verification by of the university of the level of training that they imply, as long as in the country where said title was issued it allows access to university postgraduate level studies. In no case will access through this route imply the homologation of the previous degree held by the interested party or its recognition for other purposes than that of carrying out the Master's degree.