This guide is maintained as a current resource for September 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Detailed guide explaining what testamentary capacity is in England and Wales, the legal test from Banks v Goodfellow, how courts assess capacity, relevant evidence and practical considerations in contested will cases.
Testamentary capacity is the legal term used to describe a person's mental and legal ability to make or amend a valid will. If a testator - the person writing the will - lacks the necessary capacity at the time the will is made, the document can be challenged and declared invalid by the courts. Testamentary capacity is distinct from general mental capacity in other legal contexts and remains one of the most common grounds for contesting a will in England and Wales. This article explains the legal principles, the test applied by the courts, how capacity is assessed, and what practical steps may be involved in contested probate.
The Importance of Testamentary Capacity
A valid will must genuinely reflect the testator's intentions. Without sufficient capacity, a will does not meet legal standards and cannot be given effect. Contesting a will on this basis typically arises when a beneficiary, relative or other interested party believes the testator did not understand what they were doing when the will was created. If testamentary capacity is successfully challenged, the will can be invalidated, which may result in an earlier will taking effect or the estate being distributed under the intestacy rules.
The Legal Test: Banks v Goodfellow
In England and Wales, the test for testamentary capacity is derived from the landmark 1870 case Banks v Goodfellow (1870) LR 5 QB 549 and remains the authoritative standard used by courts. Under this common‑law test, a testator must demonstrate the following at the time the will is made:
- Understanding the nature and effects of making a will: The individual must appreciate that they are creating a legal document that disposes of their assets after death.
- Understanding the extent of their property: The testator should have a broad awareness of the nature and value of the estate they are disposing of.
- Comprehending and appreciating beneficiary claims: They must understand who might expect to benefit and how their decisions affect those potential beneficiaries.
- Freedom from mental disorder or delusion influencing decisions: The testator should not suffer from a disorder of the mind or delusion that perverts their sense of right or prevents them from exercising normal faculties in making decisions about their estate.
These criteria focus on the testator's mental state at the specific time the will was formulated and executed, not on general intelligence, character or memory.
Presumption of Capacity
The law generally presumes capacity where a will appears rational and properly executed, particularly if it was drafted by an independent solicitor. This presumption can only be rebutted by presenting evidence that raises a real doubt about the testator's mental state when the will was made. If such a doubt is raised, the burden of proof can shift to those defending the will to demonstrate that capacity did exist.
Testamentary Capacity vs. Mental Capacity Act 2005
The Mental Capacity Act 2005 provides a statutory framework for assessing general capacity in many legal contexts such as health and financial decisions. However, it does not replace the common‑law test for testamentary capacity. Courts have confirmed that Banks v Goodfellow remains the sole legal standard for will validity, although the Mental Capacity Act may be used as an additional reference in some cases. The common‑law test sets a specific threshold tailored to will‑making and is considered a separate test from the broader statutory framework.
Evidence and Assessment of Testamentary Capacity
Proving lack of testamentary capacity requires evidence that the testator did not meet the Banks v Goodfellow criteria when the will was made. Common forms of evidence include:
- Medical records and expert opinions: Historical medical records and retrospective expert assessments can be used to show cognitive impairment such as dementia or delirium at the relevant time.
- Solicitors' attendance notes: Detailed records from the professional preparing the will can indicate whether the testator understood the process.
- Witness statements: Statements from family members and carers about the testator's behaviour at the time the will was executed may support or refute capacity.
Professionally conducted testamentary capacity assessments, often performed by qualified clinicians, can provide contemporaneous evidence about the testator's mental state. These assessments adhere to best practice, including the Banks v Goodfellow criteria, and can be used to support or defend a will's validity.
Practical Examples of Capacity Challenges
Testator with Cognitive Impairment
If a person suffering from conditions such as dementia executes a will shortly before death, opponents may argue that they did not understand the nature and effect of their decisions. Medical evidence showing confusion or impaired judgment at that time can strengthen such a challenge.
Sudden or Unexplained Will Changes
Significant changes to a will that depart from previous versions, particularly where the testator was known to be in poor health, may also prompt questions about capacity. In these situations, contemporaneous evidence such as medical notes or solicitor records is crucial.
Time Considerations and Limitations
There is no fixed statutory time limit for challenging a will on the basis of lack of testamentary capacity. However, challenges must be made promptly because delay often weakens the availability and reliability of evidence, and the estate may have already been distributed. Early identification and gathering of relevant documentation significantly improve prospects of success.
Common Questions
Does having dementia automatically mean lack of testamentary capacity?
No. A diagnosis alone does not annul capacity. What matters is whether the condition affected the individual's ability to meet the legal criteria at the moment the will was made.
Can a will still be valid if the testator had a poor memory?
Yes. Memory gaps alone do not invalidate a will if the testator understood the will‑making process, the nature of their estate and the claims of potential beneficiaries.
Does professional involvement in will preparation prove capacity?
Professional drafting and execution reduce the risk of successful challenges but do not guarantee validity. Detailed notes or assessments by the solicitor at the time can strengthen the presumption of capacity.
Key Takeaways
Testamentary capacity is a fundamental requirement for a valid will in England and Wales. The legal standard, stemming from Banks v Goodfellow (1870), requires that a testator understands the nature and effects of making a will, appreciates the extent of their estate and understands the claims of beneficiaries, without mental disorder influencing their decisions. Capacity is presumed in rational, properly executed wills but can be challenged with appropriate evidence. Understanding the legal test, how it is assessed and the importance of evidence is essential for anyone involved in contested probate matters.
