Validity of wills and codicils - Testamentary capacity

Learning Outcomes

This article explains testamentary capacity in wills and codicils, including:

• How the Banks v Goodfellow criteria operate in practice and how to apply each limb to varied fact patterns involving delusions, psychiatric illness, grief, and complex family structures
• How to identify the material time for capacity, analyse fluctuating conditions and lucid intervals, and deploy the Parker v Felgate rule to problem-style questions
• How the presumption of capacity works, when it is displaced, and how the evidential and legal burdens shift between the challenger and the propounder of the will
• The relationship between Banks v Goodfellow and the Mental Capacity Act 2005, highlighting doctrinal differences, exam-relevant overlaps, and common traps for SQE1 candidates
• Best-practice steps under the golden rule, including when to seek medical evidence, what instructions to give clinicians, and how to draft robust, exam-ready attendance notes
• The distinctions between capacity, knowledge and approval, and undue influence, and how to structure an answer that treats each ground separately while recognising overlap in the evidence
• How capacity for codicils is assessed, how later instruments interact with earlier wills, and how to reason through scenarios where only the codicil is invalid
• Techniques for spotting capacity issues quickly in multiple-choice questions and structuring clear, logical reasoning that uses key authorities and terminology

SQE1 Syllabus

For SQE1, you are required to understand the requirements for a valid will and codicil, with a focus on testamentary capacity, with a focus on the following syllabus points:

• the common law test for testamentary capacity (Banks v Goodfellow)
• the timing of capacity and the effect of fluctuating mental states
• the distinction between testamentary capacity and general mental capacity under the Mental Capacity Act 2005
• the practical steps solicitors should take when capacity is in doubt
• how capacity issues may affect the validity of wills and codicils in exam scenarios
• the rule in Parker v Felgate and how instructions given when capacitated can support later execution
• the presumption of capacity and the evidential burden when capacity is challenged

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. What are the three main elements of the Banks v Goodfellow test for testamentary capacity?
2. At what point in time must a testator have capacity to make a valid will?
3. How does the Mental Capacity Act 2005 interact with the common law test for testamentary capacity?
4. True or false: A person diagnosed with dementia can never make a valid will.

Introduction

Testamentary capacity is a core requirement for the validity of any will or codicil. For a will to be admitted to probate, the testator must have had the mental ability to understand what they were doing and the consequences of their decisions. This article explains the legal test for capacity, when capacity must be present, and the practical steps to take when capacity is in doubt.

A valid will also requires that the testator is at least 18 years old (Wills Act 1837, s 7), save for limited “privileged wills” exceptions (s 11) for certain members of the armed forces and seafarers. Mental capacity is presumed, but if credible evidence raises doubt, those propounding the will must prove capacity on the balance of probabilities. Capacity is distinct from knowledge and approval and from undue influence—each must be considered separately when validity is in issue.

Key Term: testamentary capacity
The mental ability required for a person to make a valid will or codicil. The testator must understand the nature of making a will, the extent of their property, and the claims of potential beneficiaries.

The Legal Test for Testamentary Capacity

The leading authority for testamentary capacity is the common law case of Banks v Goodfellow (1870). This test remains the standard for assessing whether a person is capable of making a valid will or codicil.

Key Term: Banks v Goodfellow test
The common law criteria requiring a testator to understand the act of making a will, the extent of their property, and the claims of potential beneficiaries, free from any disorder of the mind affecting their decisions.

Courts begin with a presumption that the testator had capacity. If a challenger produces cogent evidence of incapacity (for example medical records suggesting dementia or severe depressive illness at or near the material time), the evidential burden shifts to the propounder to establish capacity. The overall civil standard applies—proof on the balance of probabilities—based on all the evidence (lay and expert). This approach preserves the probative value of validly executed wills while ensuring protection where capacity is genuinely in doubt.

The Banks v Goodfellow Criteria

To have testamentary capacity, the testator must:

1. Understand the nature of making a will and its effects.
2. Know the extent of the property they are disposing of.
3. Be able to comprehend and appreciate the claims of those who might expect to benefit from the estate.
4. Not be affected by any mental disorder or delusion that influences the will's provisions.

Each limb is applied in a practical way:

• Nature and effects: The testator need not understand every technical legal mechanism, but must appreciate that a will disposes of their estate on death and the broad effect of their dispositions.
• Extent of property: Exact values are unnecessary; a general awareness of the types and approximate scale of assets suffices, especially where the estate is substantial or complex.
• Claims to consider: The testator should bring to mind those with a moral claim (close family, dependants) and be able to evaluate them, though they may decide to leave them nothing.
• Disorders and delusions: Capacity fails only if the mental disorder or delusion actually poisons the affections or perverts judgment in a way that influences the dispositions. Mere eccentricity or irrelevant delusions do not of themselves negate capacity.

Worked Example 1.1

A testator, aged 82, wishes to make a will. She has mild memory loss but can explain that she is making a will, lists her house and savings, and names her children and grandchildren, stating why she wants to leave her estate in a particular way. She sometimes believes her late husband is still alive but does not mention him in her will.

Answer:
The testator likely has testamentary capacity. She understands the act, her property, and the relevant people. Her mistaken belief about her husband does not affect the will's provisions, so it does not invalidate capacity.

Timing of Capacity

Capacity must be present at the time the will or codicil is executed. If the testator's mental state fluctuates, capacity must be assessed at the moment of signing. If the testator had capacity when giving instructions but lost it before execution, the will may still be valid if, at signing, the testator understands they are executing a will prepared according to their earlier instructions.

Key Term: material time
The relevant moment for assessing testamentary capacity—usually the time the will or codicil is executed.

Testamentary capacity is decision-specific and time-specific. The law recognises lucid intervals—periods during which a person with a fluctuating condition (for example dementia, delirium, or the aftermath of a stroke) regains sufficient clarity to meet the Banks v Goodfellow test. A will executed during a lucid interval will be valid if the testator then satisfies the criteria, even if they lacked capacity earlier in the day or on different days.

Key Term: lucid interval
A temporary period of clarity during a fluctuating mental condition in which the testator regains sufficient understanding to meet the Banks v Goodfellow test.

The common law also recognises a limited exception where instructions were given while capacitous but capacity was lost by the time of execution.

Key Term: Parker v Felgate rule
Where a testator had capacity when giving instructions, the will was prepared in accordance with those instructions, and at execution the testator understands they are signing the will prepared from those instructions, the will may be valid despite loss of capacity between instruction and execution.

This exception is applied cautiously. The longer the gap between instruction and execution, the greater the need for clear evidence that the will accords with the earlier instructions and that the testator at execution appreciated they were signing that will. Courts have applied this rule even where a significant interval elapsed, provided the evidential conditions are met.

Worked Example 1.2

A solicitor takes instructions from a client with early dementia. The client is lucid and gives clear instructions. Two weeks later, at the will signing, the client is confused and cannot recall the instructions or the purpose of the document.

Answer:
The will is not valid. Capacity must exist at the time of execution. If the testator cannot understand they are signing a will, the Banks v Goodfellow test is not satisfied.

Worked Example 1.3

A testator with fluctuating capacity due to vascular dementia has poor mornings but clear evenings. The solicitor attends at 7pm; the testator converses coherently, explains the nature and effect of the will, identifies her property and close family, and signs in proper form.

Answer:
The will is likely valid. A lucid interval at the material time suffices if the Banks v Goodfellow criteria are met at execution.

Worked Example 1.4

A testator gives detailed instructions to a solicitor in January, fully capacitated. After a stroke in March, he loses capacity. In April he signs the will. He does not remember the content of his January instructions but, when the will is presented, he understands he is signing the will prepared from earlier instructions and confirms this.

Answer:
The will may be valid under the Parker v Felgate rule, provided the April document was prepared in accordance with the January instructions and the testator at execution understood that fact. Evidence (attendance notes, drafts, witness statements) will be important.

The Mental Capacity Act 2005 and Testamentary Capacity

The Mental Capacity Act 2005 (MCA 2005) sets out a statutory test for mental capacity in general decision-making. However, for wills and codicils, the common law Banks v Goodfellow test remains the standard. The MCA 2005 may be relevant in some cases, but it does not replace the common law test for testamentary capacity.

Key Term: Mental Capacity Act 2005
Legislation providing a statutory framework for assessing capacity in general decisions, but does not override the common law test for testamentary capacity.

Post-Act authorities confirm that Banks v Goodfellow governs wills. The MCA’s formulation—understand, retain, use/weigh and communicate—guides Court of Protection decisions and many everyday decisions, but for testamentary capacity courts have repeatedly applied Banks v Goodfellow and highlighted differences:

• burden of proof under common law shifts to the propounder once doubt is raised; the MCA presumes capacity and places the burden on the person alleging lack of capacity in its own jurisdiction
• the MCA’s requirement to understand all information relevant to the decision (including reasonably foreseeable consequences) can be more demanding than Banks v Goodfellow, which focuses on nature/effect, extent, and claims
• in will cases, it is not necessary to understand the wider commercial or relational significance of choices if the Banks limbs are satisfied (for example, a testator need not understand the corporate control implications of share splits, provided they understand their property and the effect of equal division)

Judicial remarks and the MCA Code of Practice acknowledge alignment in principle but maintain that the common law test continues to apply to wills. The MCA is nevertheless relevant to surrounding facts (for example, whether the person generally lacked capacity and therefore had attorneys or deputies, or whether a statutory will was considered), but it does not displace Banks v Goodfellow for testamentary capacity.

In practice, the MCA offers a structured approach for clinicians assessing capacity and can supply persuasive evidence, but the probate court ultimately applies the common law test.

Exam Warning

For SQE1, do not confuse the Banks v Goodfellow test with the statutory test under the Mental Capacity Act 2005. The exam will expect you to apply the common law test to questions on wills and codicils.

Worked Example 1.5

A testator has an MCA-compliant clinical assessment two months before signing a will, concluding that he can manage routine financial decisions but struggles to weigh complex consequences. At execution, he understands he is making a will, identifies his assets and family claims, and explains his choices.

Answer:
The will is likely valid under Banks v Goodfellow. The MCA assessment is informative but not determinative; the probate court applies the common law test. On these facts, the key elements are satisfied at the material time.

Delusions and Disorders of the Mind

A testator may have a mental disorder or delusion, but this only affects capacity if it influences the will's provisions. If the delusion does not affect the distribution of the estate, capacity may still be present.

Key Term: delusion (testamentary context)
A fixed false belief. Only relevant to capacity if it affects the testator's decisions about the will.

Examples illustrate the line:

• an irrelevant delusion (e.g., that neighbours are spies) that does not bear on dispositions is unlikely to defeat capacity
• a delusion that poisons affections (e.g., the false belief that a devoted child is an imposter or persecutor) can undermine capacity if it explains exclusion or materially altered gifts
• acute bereavement may produce symptoms akin to severe depression; capacity can be impaired where the testator cannot process claims or understand effects due to that state. Equally, grief alone does not negate capacity if the criteria are otherwise met at execution

The inquiry is fact-sensitive. Medical and lay evidence should be examined to determine whether any disorder or delusion caused the dispositions which would not have been made if the mind had been sound.

Worked Example 1.6

A testator has a fixed false belief that his daughter has been stealing from him (no evidence supports this). He excludes her, leaving the estate to distant acquaintances. He otherwise understands his property and the nature of the will.

Answer:
Capacity may be lacking. If the exclusion flows from the delusion and would not have been made if his mind were sound, the fourth limb of Banks v Goodfellow is not met.

Practical Steps When Capacity Is in Doubt

Solicitors should take extra care when a testator is elderly, ill, or has a history of mental impairment. The "golden rule" is to obtain a medical opinion on capacity and, if possible, have a doctor witness the will. Detailed attendance notes should be kept.

Key Term: golden rule (wills)
The best practice that, where capacity is in doubt, a medical practitioner should confirm the testator's capacity and ideally witness the will.

Good practice includes:

• arranging a contemporaneous capacity assessment by a suitably qualified clinician (ideally with experience in cognitive disorders), explaining the Banks v Goodfellow criteria
• timing the meeting when the testator is typically most lucid (for fluctuating conditions), and documenting observations carefully
• seeing the testator alone to assess independence and to reduce risks of undue influence; avoid relying on instructions via an intermediary with an interest
• ensuring the testator articulates the nature and effects of the will, identifies asset classes and approximate values, and explains their reasons for dispositions
• recording all discussions, property checks, and any inconsistencies in detailed file notes; consider video recording where appropriate and proportionate
• if medical attendance is not possible, making a careful written assessment yourself and proceeding promptly if delay would risk loss of capacity; explain to the client the potential risks of challenge and costs implications

Complying with the golden rule provides strong evidence but does not guarantee validity. Conversely, non-compliance does not automatically invalidate a will; it may, however, leave insufficient evidence to rebut doubts, especially where serious cognitive impairment is alleged. Courts may take a pragmatic view where urgent circumstances made medical attendance impracticable, provided the solicitor’s own assessment is careful and credible. Cost consequences can be affected by whether the circumstances reasonably led to investigation and challenge.

Revision Tip

If the exam scenario mentions an elderly or unwell testator, consider whether the solicitor should have followed the golden rule and obtained medical evidence of capacity.

Capacity and Codicils

The same test for capacity applies to codicils as to wills. If a testator lacks capacity at the time of executing a codicil, the codicil is invalid, even if the original will was valid. Because a codicil speaks from its own date and may alter dispositions or republish a will, ensure capacity at the codicil’s execution. The Parker v Felgate rule can apply to codicils where capacitous instructions are followed by execution after loss of capacity and the testator understands at signing that they are executing the instrument prepared from those instructions.

Worked Example 1.7

A testator made a valid will two years ago. Now, with moderate dementia, he signs a codicil redirecting residue from a charity to a friend. At execution he cannot explain the nature and effect of the codicil or recall the rationale for the change.

Answer:
The codicil is likely invalid due to lack of capacity at execution. The original will remains valid and governs unless there is a different valid later instrument.

Capacity and Undue Influence

Testamentary capacity and undue influence are separate issues. A testator may have capacity but still be subject to undue influence. For a will to be valid, the testator must act freely and voluntarily. Suspicious circumstances (e.g., a substantial benefit to a person who arranged the will and was present throughout) may invite scrutiny of knowledge and approval or undue influence, but they do not, without more, prove lack of capacity. Analyse each ground distinctly:

• capacity: ability to understand, recall, and evaluate claims and property, free of dispositive delusions
• knowledge and approval: awareness of and agreement to the contents
• undue influence: coercion or manipulation overriding free will

Summary Table: Testamentary Capacity vs. Mental Capacity Act 2005

Key Point Checklist

This article has covered the following key knowledge points:

• The Banks v Goodfellow test is the standard for testamentary capacity in wills and codicils.
• Capacity must be present at the time of execution, or the will is invalid.
• A lucid interval at execution can suffice; capacity is time-specific and decision-specific.
• The Parker v Felgate rule may validate a will where instructions were given with capacity and the testator at execution understands they are signing the will prepared from those instructions.
• The Mental Capacity Act 2005 does not replace the common law test for wills; key differences include the burden of proof and the scope of information to be weighed.
• Delusions only affect capacity if they influence the will's provisions.
• Solicitors should obtain medical evidence of capacity where there is doubt (the golden rule), keep detailed notes, and see the testator alone where possible.
• The same test applies to codicils as to wills; capacity is assessed at the time the codicil is executed.
• Capacity, knowledge and approval, and undue influence are separate grounds affecting validity and must be analysed distinctly.

Key Terms and Concepts

• testamentary capacity
• Banks v Goodfellow test
• material time
• Mental Capacity Act 2005
• delusion (testamentary context)
• golden rule (wills)
• lucid interval
• Parker v Felgate rule