The Law of Succession and Testamentary Capacity in Wills Disputes in Ondo State

Testamentary capacity disputes, in which the validity of a will is challenged on the grounds that the testator lacked the mental capacity to make a legally effective will, are increasingly common in Nigerian probate proceedings. This study examines the legal standard for testamentary capacity and its application in wills disputes in Ondo State, South West Nigeria, analysing decisions from the Ondo State High Court between 2019 and 2024. Using a doctrinal methodology supplemented by interviews with 20 probate lawyers and 10 medical experts in Akure, the research evaluates the Banks v Goodfellow test of testamentary capacity as applied in Nigerian courts, examining how courts assess evidence of dementia, psychiatric illness, and undue influence. Findings reveal that Nigerian courts rely heavily on medical evidence which is frequently absent or inconclusive, creating significant evidential challenges for both claimants and defendants in capacity disputes. The study further examines how the absence of standardised wills drafting practices contributes to the proliferation of disputes. The research argues that Nigerian probate law requires more detailed statutory guidance on capacity assessment, greater judicial engagement with medical expert evidence, and mandatory best-practice guidelines for legal practitioners who draft wills for elderly or vulnerable clients. Recommendations include reform of the Wills Law and professional conduct rules for estate planning lawyers. Keywords: testamentary capacity, wills, succession, probate, Ondo State