Testamentary Capacity and Succession Agreements in Later Life: A Spanish Perspective

Population ageing is reshaping the assumptions on which succession law has traditionally rested. This article examines how Spanish succession law responds to this demographic shift through two closely connected dimensions: testamentary capacity and the growing role of succession agreements. The analysis adopts a doctrinal and comparative perspective within the Spanish legal system, taking account of the coexistence of the Spanish Civil Code and several autonomous succession regimes. It argues that testamentary capacity remains governed by a deliberately low and functional threshold, centred on the testator’s actual ability to form and express a testamentary intention at the time of execution, and that notarial ex ante control is central to preserving both autonomy and legal certainty. At the same time, relational vulnerability in later life requires distinct safeguards aimed at preserving testamentary freedom. The article further shows that succession agreements, often viewed as restrictions on testamentary freedom, may also operate as instruments of anticipatory autonomy. The central challenge is to make autonomy effective across time without confusing vulnerability with incapacity, or protection with constraint.