Testamentary capacity revisited: Insights from the Law Commission’s May 2025 report on wills law reform

Tori Keyte, Trainee Solicitor in the Private Wealth Department , shares her thoughts on the recent Law Commission report and its significance for testamentary capacity and wills law reform.

Testamentary capacity, which is the mental ability required to make a valid will, is a cornerstone of inheritance law, ensuring that an individual’s final wishes are respected and legally effective. As society evolves and our understanding of mental capacity deepens, so too must the legal frameworks that govern capacity.

The Law Commission’s recent report on the proposed reform of the law relating to wills marks the most significant proposed update in over a century, addressing modern challenges such as increased life expectancy, neurodegenerative conditions like dementia and developments in medicine. This blog considers the implications of the changes proposed by the Law Commission surrounding testamentary capacity.

Current legal framework

For over 150 years, the test for testamentary capacity has been governed by the common law decision in Banks v Goodfellow (1870).

Banks v Goodfellow sets out that to make a valid will, a person must understand:

• the nature and effect of making a will;
• the extent of their property;
• the claims to which they ought to give effect; and
• must not be suffering from any disorder or delusion affecting these judgments.

 This test has provided certainty over the last two centuries. However, Banks was decided in a very different era, one where life was shorter, understanding of mental health was limited, and neurodegenerative diseases were rarely diagnosed.

The Mental Capacity act 2005

The Mental Capacity Act 2005 (MCA) sets a statutory framework for decision-making on behalf of individuals who lack capacity, and is the leading legislation governing mental capacity in all other areas of law.

A person lacks capacity if, at the material time, they are unable to make a decision due to an impairment of, or disturbance in the functioning of, the mind or brain (s.2(1)). The MCA requires that a person can:

• understand the relevant information;
• retain that information;
• use or weigh the information as part of the decision-making process; and
• communicate their decision

The Law Commission’s recommendations

The Law Commission now recommends that we move forward by replacing the old common law test with the clear, statutory principles set out in the Mental Capacity Act 2005 (MCA).

Key recommendations include:

• Modernising the test: replacing the common law Banks v Goodfellow standard with the statutory test under the MCA will provide clarity and consistency. This would ensure one universal test for testamentary capacity, one that is far more inclusive and considerate of modern changes in psychiatric medicine, capacity and society.
• Digital wills: whilst the MCA was implemented before digital wills, its principles and test for capacity are designed to be decision-specific and context-sensitive. The MCA’s practical and diagnostic structure makes it adaptable to digital-will making, which is becoming an increasing practice in the modern technological era. The Law Commission proposals also provide for fully electronic wills to be an option in future, when the technology allows for these to be put in place with a reliable system and appropriate safeguards.
• Support for vulnerable individuals: emphasising support for those on the margins of capacity, ensuring that vulnerability is not a barrier to making a will. The MCA contains a statutory principle that ‘a person is not to be treated as unable to make a decision unless all practicable steps to help them do so have been taken without success” (s 1(3))’, reiterating that a lack of capacity should not be assumed just because someone is older, unwell or vulnerable.
• Presumption of capacity: maintaining the principle that adults are presumed to have capacity, making it more difficult for valid wills to be challenged without evidence. This presumption aligns wills law with other areas of decision-making and reflects contemporary human rights standards.

Implications of the Proposed Changes

For testators and families

A single statutory test would bring greater certainty to the process, empowering individuals and families by reducing the likelihood of unwarranted challenges to valid wills. It places individuals’ autonomy at the forefront, protecting the intentions of those who wish to make arrangements for their estates, even when faced with health or communication challenges.

For legal practitioners

For solicitors and professionals, these reforms mean clearer guidelines and less ambiguity, streamlining the advice process. Practitioners will need to ensure that assessments of capacity are thoroughly documented in line with the MCA, enhancing the protection of clients’ wishes and reducing disputes.

We welcome the Law Commission’s commitment to clarity, fairness, and modernisation. By harmonising the test for capacity with the MCA, the law becomes both more accessible and better suited to today’s society. As private wealth lawyers, these reforms are an opportunity to guide clients confidently through change, ensuring their wishes are properly recorded and respected.

The Law Commission’s report marks an historic shift in how testamentary capacity is understood and assessed. By adopting a clear statutory test, the law can better serve individuals and families in an increasingly complex world.