The jurisprudential reconstruction of the principle of invalidity of the legitimate portion in the face of contemporary challenges: between private autonomy and family protection

Abstract

This paper analyzes the quantitative and qualitative inviolability of the statutory share as a structural principle of Spanish inheritance law, designed to guarantee the effectiveness of the forced heirs’ rights against testamentary dispositions or inter vivos acts that could diminish their legal portion. From a dogmatic perspective, a distinction is made between the quantitative aspect, aimed at preserving the minimum legal share through actions for supplementation and reduction, and the qualitative aspect, intended to prevent the imposition of unauthorized encumbrances, conditions, or limitations on the strict statutory share (Articles 813 and 815 of the Civil Code).

The jurisprudence of the Supreme Court has consolidated a system of corrective —rather than annulment— protection that allows for the reclassification of simulated transactions, the inclusion of disguised gifts in the calculation of the statutory share, and the declaration of ineffectiveness of clauses that distort the statutory share. Current problems center on determining the time limit for exercising reduction actions, the relationship between preterition and actions for inheritance, the distinction between nullity and supplementation, and the difficulties arising from calculating the estate and the gift.

It is concluded that the inviolability of inheritances operates as a dynamic mechanism for balancing testamentary freedom and family protection, the practical application of which continues to be the subject of jurisprudential development and doctrinal debate.