- Testamentary capacity is a legal question not a medical issue.
- Evidence to prove or disprove testamentary capacity needs to address the elements from the rule in Banks v Goodfellow.
- The evidence needs to focus on the time at which the testator gave instructions for the preparation of the will and its execution.
Estate litigation in NSW has grown markedly since the turn of the century. Statistics published by the Supreme Court of NSW (as at 26 June 2019) show that since 2015 more than 1,000 cases in probate and family provision have been commenced each year in the Supreme Court alone. A consequence of that volume of litigation is that practitioners who may not have undertaken much, if any, of this work in the past are now being required to run or defend these cases. The purpose of this article is to provide some practical assistance for practitioners dealing with an issue that commonly arises in estate litigation – testamentary capacity.
In order to make a valid a will, a testator must comply with certain formal requirements and have the requisite mental capacity. Testamentary capacity is therefore an issue of importance to any person seeking to propound a will and, potentially, to any person seeking to contest the validity of the will.
The test for testamentary capacity
The test for testamentary capacity, known as the rule in Banks v Goodfellow (1870) LR 5 QB 549, was expressed in contemporary language by Basten JA in Carr v Homersham (2018) 97 NSWLR 328 (at -) as containing three affirmative elements and one negative element. The affirmative elements are that the testator must:
(a) have the capacity to understand the nature of the act of making a will and its effects;
(b) understand the extent of the property the subject of the will; and
(c) have the capacity to comprehend the moral claims of potential beneficiaries.
The negative element is that the testator must not be suffering from a condition that interferes with his or her normal decision-making concerning the testamentary dispositions.
It is important to remember that the rule in Banks v Goodfellow should not be read and treated as though it were a legislative enactment (Mikhail v Hana  NSWCA 97 at ).