When to Seek a Testamentary Capacity Assessment

Wills are often made at difficult moments, so clarity matters. This guide explains when a testamentary capacity assessment is sensible, how the legal tests work, and what good practice looks like. It blends plain-English explanations with practical steps you can act on today, so families and solicitors can protect a person’s wishes without unnecessary friction.

“A person must be assumed to have capacity unless it is established that he lacks capacity.” Legislation.gov.uk opens in a new tab

“We recommend that only one test should apply, the modern test in the Mental Capacity Act 2005.” Law Commission opens in a new tab

The first quote is the foundation of everyday decision-making under the Mental Capacity Act 2005. The second is a Law Commission recommendation published on 16 May 2025, helpful context for where reform may be heading, but not the law today. Legislation.gov.uk opens in a new tab, Law Commission opens in a new tab

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What “testamentary capacity” means, in practice

For will-making, the long-standing common law test from Banks v Goodfellow still governs capacity in England and Wales. The courts have repeatedly confirmed this since the MCA 2005 came into force, for example in Walker v Badmin and on appeal in Clitheroe v Bond. In short, at the time of making the will the person must be able to:

1. understand the nature and effect of a will,
2. understand the broad extent of their estate,
3. consider those who might reasonably expect to benefit and the claims on them,
4. not be affected by a disorder of the mind that poisons their affections or decisions in a way that affects the will. STEP opens in a new tab, Macfarlanes opens in a new tab, Radcliffe Chambers (pdf) opens in a new tab

Why this matters: if these elements are evidenced clearly at the time, the will is far more likely to withstand a later challenge.

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Banks v Goodfellow vs the MCA 2005, what is the difference

• Banks v Goodfellow is specific to will-making. It remains the operative legal yardstick when deciding whether a person had capacity to make their own will. STEP opens in a new tab
• The MCA 2005 provides the everyday, decision-specific framework that clinicians and social care use. It is built on five principles, including the presumption of capacity and the right to make an unwise decision. Capacity is assessed functionally, can the person understand, retain, use or weigh, and communicate the relevant information at the time. Legislation.gov.uk opens in a new tab

Current position: the Law Commission has recommended moving wills onto the MCA test in a future Wills Act, and the Government has published an initial response. Until Parliament changes the law, Banks still applies to will-capacity. Law Commission opens in a new tab, GOV.UK opens in a new tab

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The Golden Rule, why solicitors sometimes ask for medical input

Where a testator is elderly or seriously ill, best practice is to obtain a contemporaneous medical opinion on capacity, and to keep careful notes. This Golden Rule comes from Templeman J in Kenward v Adams and Re Simpson. It is guidance, not a strict rule of law, but courts look closely at whether good practice was followed when a will is later disputed. Magdalen Chambers opens in a new tab, Pump Court Chambers opens in a new tab

“Solicitors should err on the side of caution, taking positive steps to assess capacity themselves, and in more extreme cases seeking medical advice.” journal.step.org opens in a new tab

How we apply it: we coordinate with the will-drafter and, where appropriate, an independent medical practitioner, so there is clear, proportional evidence close to the time of execution.

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Real-world scenarios, pain points, and what good looks like

1) New dementia diagnosis, family wants to update a will

Typical worry: “A diagnosis means no will,” or “It will be challenged whatever we do.” In fact, a diagnosis does not automatically remove testamentary capacity, the key is whether the Banks elements are met at the time of the decision. Alzheimer’s Society opens in a new tab
What good looks like: assess at the person’s best time of day, use accessible explanations, check understanding of the act of making a will, the estate in broad terms, and who might expect to benefit, and record clear reasons where instructions differ from past patterns. Macfarlanes opens in a new tab

2) Fresh bereavement, rapid change of will

Typical risk: grief and pressure can affect decision-making, and execution in haste can invite challenge on capacity and knowledge and approval. The Key v Key case is often cited where immediate post-bereavement changes failed. Mental Health Law Online opens in a new tab
What good looks like: if safe, allow a short stabilisation period, meet privately for part of the interview to exclude undue influence, and make detailed attendance notes explaining the person’s reasoning in their own words. NICE opens in a new tab

3) Hospital or care home, last minute instructions

Typical barriers: infection, delirium, medication, pain, environmental noise, or fatigue. Capacity can fluctuate over hours and days. nhs.uk opens in a new tab
What good looks like: choose a quiet room, time the assessment to the person’s optimum period, build breaks in, confirm understanding is free from coercion, and document the steps taken to minimise influence. NICE opens in a new tab

4) Dominant relative or carer organising the will

Typical worry: fear of undue influence when a beneficiary is heavily involved. Good practice is to see the testator alone for key parts, probe reasons for any exclusions, and ensure interpreters or communication aids are in place where needed. NICE is explicit about watching for undue influence when supporting decision-making. NICE opens in a new tab

5) Remote witnessing during the pandemic, is the will still valid

The rule now: the temporary law that allowed video witnessing ended on 31 January 2024. Wills validly witnessed by video between 31 January 2020 and 31 January 2024 remain valid, but new wills must be witnessed in person. UK Parliament opens in a new tab, Ashfords opens in a new tab
Actionable step: if a prior will was video-witnessed, ask your solicitor to check it against the former rules and consider re-executing in person if there is any doubt. Ashfords opens in a new tab

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Practical tips to reduce the risk of a later dispute

Prepare well, but keep it simple

• Bring a brief medication and diagnoses list, and any recent clinic letters or care plans. These add context, they do not replace the capacity assessment.
• List main assets in broad terms, property, savings, investments, not a line-by-line inventory.
• Note the people with a potential moral claim, and your reasons if you plan to depart from earlier patterns. Macfarlanes opens in a new tab

Choose the right setting and timing

• Pick the time of day when the person is sharpest, for many people with dementia this is the morning.
• Keep the room quiet, limit attendees, and build breaks in to avoid fatigue. Document all of this. nhs.uk opens in a new tab

Guard against undue influence

• The assessor should see the person alone for part of the interview, check they understand they can change their mind, and record their reasoning in their own words. NICE guidance highlights the need to avoid coercion and pressure. NICE opens in a new tab

Be evidence-minded, not box-ticking

• Capacity is decision and time specific under the MCA, and Banks remains the legal yardstick for wills. Make a clear note of the person’s understanding of the act, their estate, the people who might expect to benefit, and any relevant mental health factors. Radcliffe Chambers (pdf) opens in a new tab, Legislation.gov.uk opens in a new tab

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How an AJH capacity assessment helps, practically

• Focused interviews that maximise understanding first, assess second, aligned with MCA support principles while applying Banks for the will decision. Legislation.gov.uk opens in a new tab
• Proportionate collateral information, recent letters and care plans where available, to inform but not replace the functional analysis.
• Clear, court-ready documentation, setting out the person’s reasoning, the steps taken to optimise capacity, and our clinical findings against the Banks elements. Macfarlanes opens in a new tab
• Coordination with the will-drafter and, where needed, a medical practitioner, so the Golden Rule is observed sensibly without adding unnecessary delay. Magdalen Chambers opens in a new tab

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Short expert insights you can share with the family

• Law Commission on reform: “We recommend that only one test should apply, the modern test in the Mental Capacity Act 2005.” Use this to explain headlines without causing panic, because it is a recommendation, not enacted law. Law Commission opens in a new tab
• MCA principle: “A person must be assumed to have capacity unless it is established that he lacks capacity.” Helpful to reduce anxiety that an assessment is a test designed to take rights away. Legislation.gov.uk opens in a new tab
• STEP on good practice: “Solicitors should err on the side of caution, taking positive steps to assess capacity themselves, and in more extreme cases seeking medical advice.” A supportive way to introduce the Golden Rule. journal.step.org opens in a new tab

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Worked examples

Mrs L, 82, early Alzheimer’s, changing a long-standing gift
Morning assessment at home with her daughter waiting in another room. Mrs L explained the act of making a will, outlined her home, savings, and premium bonds in broad terms, and gave clear reasons for reducing a gift to a distant relative due to lack of contact. No delusional beliefs identified. Will signed in person later that day with two witnesses. Outcome: robust evidence against all four Banks limbs. Macfarlanes opens in a new tab

Mr K, 75, bereaved two weeks ago, sudden instruction to disinherit a child
Capacity and knowledge and approval at risk due to acute grief and pressure from a relative. We advised a short pause, a private meeting without the relative present, and contemporaneous notes of reasons. The solicitor obtained a medical opinion in line with the Golden Rule before execution. Outcome: reduced litigation risk by addressing classic Key v Key pitfalls. Mental Health Law Online opens in a new tab, Magdalen Chambers opens in a new tab

Ms R, 68, in hospital with delirium resolving
Capacity fluctuated with infection and analgesia. We timed the assessment for a lucid period, used simple prompts, and documented why the chosen window was appropriate. Instructions were confirmed again at execution. Outcome: clear, time-specific evidence that capacity existed at the material time. nhs.uk opens in a new tab

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Action steps if you think a testamentary capacity assessment is needed

1. Speak to the will-drafter first, agree the scope, the venue, and who should attend.
2. Gather essentials, prior wills if available, a short asset overview, a medication list, recent clinic letters, any language or hearing support needs.
3. Schedule for the person’s best time of day, and plan for part of the interview to be private.
4. If age, serious illness, or red flags are present, consider a medical opinion near the time of execution, recorded and kept, in line with the Golden Rule. Magdalen Chambers opens in a new tab
5. If a pandemic-era video will exists, ask your solicitor to review it against the former rules, and consider re-executing in person if there is any doubt. Ashfords opens in a new tab

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Key sources

• Banks remains the operative test, with post-MCA confirmation in Walker v Badmin and Clitheroe v Bond. STEP opens in a new tab, Macfarlanes opens in a new tab
• MCA 2005 framework and principles for supporting decision-making. Legislation.gov.uk opens in a new tab
• Golden Rule origin and status, Templeman J, Kenward v Adams and Re Simpson, plus practitioner analysis. Magdalen Chambers opens in a new tab, Pump Court Chambers opens in a new tab
• NICE guidance on avoiding undue influence when supporting decisions. NICE opens in a new tab
• Pandemic video-witnessing ended 31 January 2024, earlier remote wills remain valid if compliant. UK Parliament opens in a new tab, Ashfords opens in a new tab
• Law Commission 2025 report and draft Wills Bill, recommendation to align with the MCA test, Government initial response. Law Commission opens in a new tab, GOV.UK opens in a new tab

Common Questions When Planning a Will