This study aims to analyze the current situation of inheritance taxation in Spain and evaluate the legitimacy crisis surrounding the decision of whether to tax mortis causa transfers, as well as the scope and conditions under which such taxation should occur. The Inheritance and Donations Tax (IDT) frequently sparks debate, and this paper aims to analyze its evolution since its transfer to the Autonomous Communities, tracing its development to the present day. A thorough examination is essential to clarify its significance within a modern tax system, its role in the new system of regional financing, and the reforms necessary for its potential continuation, while also assessing the level of public dissatisfaction it provokes. The methodology employed in this paper involved a review of the existing literature, current legislation, and available scientific-academic resources relevant to the topic. The approach is predominantly theoretical and intentionally cross-disciplinary, aimed at enhancing accessibility and comprehension.