Background: Challenges to wills on the basis of lack of testamentary capacity and/or undue influence are likely to increase over the next generation. Since contemporaneous assessment of testamentary capacity can be a powerful influence on the outcome of such challenges, there will be an associated increase in requests for expert assessment of testamentary capacity. There is a need to provide such potential experts with the knowledge and guidelines necessary to conduct assessments that will be helpful to the judicial system.

Methods: A subcommittee of the International Psychogeriatric Association (IPA) task force on “Testamentary Capacity and Undue Influence” was formed to establish guidelines for contemporaneous assessment of testamentary capacity.

Results: The task-specific criteria for testamentary capacity as outlined by Lord Chief Justice Cockburn in the well-known Banks v. Goodfellow case are described. Additional issues are identified for probing and documentation. This is designed to determine whether the testator can formulate a coherent, rational testamentary plan that connects his/her beliefs, values and relationships with the proposed disposition of assets. Rules of engagement by the expert assessor are defined as well as an approach to the clinical examination for testamentary capacity resulting in a clear and relevant report.

Conclusion: Guidelines for experts who are asked to provide a contemporaneous opinion on testamentary capacity should help to inform disputes resulting from challenges to wills. A consistent clinical approach will help the courts to make their determinations.