Lack of Testamentary Capacity: Proving a Will Is Invalid

The Banks v Goodfellow Test in Detail

In Banks v Goodfellow (1870), the Court of Queen's Bench set out the four elements of testamentary capacity that remain the law today. All four must be satisfied at the time the will was made:

1. Understand the nature of a will and its effects: The testator must understand that they are making a document that will take effect on their death and distribute their property to the named beneficiaries. This is a low threshold — a general understanding is sufficient
2. Understand the extent of their estate: The testator must have a general understanding of what they own. They do not need to know the precise value of every asset, but they must have a broad appreciation of what they are giving away
3. Comprehend the claims of those who might reasonably expect to benefit: The testator must be aware of who might have a claim on their estate — typically close family members such as a spouse and children. They do not have to make provision for these people, but they must have them in mind and consciously decide to include or exclude them
4. Not be suffering from a disorder of the mind that poisons affections, perverts the sense of right, or prevents exercise of natural faculties: This element prevents a will made under the influence of delusions, paranoid beliefs, or severe mental illness from being valid, even if the other three elements are technically met

The 2023 case of Clitheroe v Bond confirmed that the Banks v Goodfellow test remains the correct test and declined to move to the Mental Capacity Act 2005 test. The 2005 Act does not apply to testamentary capacity.

Burden of Proof

The allocation of the burden of proof in capacity cases depends on the circumstances:

• General rule: The propounder of the will (the person seeking to uphold it, usually the executor) must prove due execution and that the testator had testamentary capacity. Once this is proved, a rebuttable presumption of capacity arises
• Suspicious circumstances: If the circumstances surrounding the making of the will are suspicious (for example, the beneficiary accompanied the testator and gave instructions to the solicitor, or the will departs dramatically from earlier wills without explanation), the propounder must affirmatively prove capacity and knowledge and approval. The suspicion must be “all but dispelled”
• Once suspicious circumstances are raised: The caveator (challenger) does not need to prove incapacity — the propounder must prove capacity to the court's satisfaction

Gathering Evidence for a Capacity Challenge

The evidence needed for a capacity challenge:

• Medical records: GP notes, hospital records, psychiatric referrals, and care home records in the period leading up to and around the date the will was made. Medical records often contain crucial contemporaneous notes about cognitive function, MMSE (Mini-Mental State Examination) scores, and medications
• Solicitor's file: The file of the solicitor who prepared the will — including attendance notes, correspondence, and any capacity assessment. Pre-action disclosure of this file can be sought before litigation
• Witness statements: From family members, carers, neighbours, and others who observed the deceased's condition around the time the will was made
• Expert medical opinion: A retrospective assessment of capacity by a consultant old age psychiatrist, based on the contemporaneous medical records. This is typically required in all contested capacity cases. Cost: £3,000–£8,000 for a written report

The expert's role is to review all the available evidence and form an opinion on whether, on the balance of probabilities, the testator had testamentary capacity at the date of execution.

Dementia and Lucid Intervals

A diagnosis of dementia or Alzheimer's disease does not automatically mean that a will made during that illness is invalid. The key question is whether the testator had capacity on the specific date the will was executed.

Even in cases of significant cognitive impairment, a person may have lucid intervals — periods during which they have sufficient capacity to make a will. A will made during a lucid interval is valid.

The expert medical witness must assess whether, given the stage of the illness and the available evidence of the testator's condition on the day in question, a lucid interval is established.

The Golden Rule: Kenward v Adams

The so-called Golden Rule derives from Kenward v Adams (1975) and subsequent cases: where a solicitor is instructed to prepare a will by an elderly or seriously ill testator, good practice requires that the solicitor:

• Makes a careful assessment of the testator's capacity at the time of giving instructions and execution
• Arranges for a medical practitioner (typically the GP) to assess the testator and provide a contemporaneous opinion on capacity
• Records the basis for their assessment in the attendance note

Failure to follow the Golden Rule does not automatically invalidate the will, but it is treated as highly suspicious and raises the evidential burden on the propounder. A court may draw adverse inferences from a failure to obtain a medical assessment.

Practical Steps if You Suspect Lack of Capacity

• Enter a caveat at the Probate Registry immediately — see how to enter a caveat
• Consult a specialist contentious probate solicitor
• Request the solicitor's file for the will preparation through a pre-action protocol letter
• Apply for access to medical records under the Access to Health Records Act 1990 (access is available to certain relatives after a person's death)
• Gather statements from anyone who observed the deceased's condition around the time the will was made
• Note the time limits — particularly for Inheritance Act claims (6 months from grant of probate)

For the overall contentious probate picture, see our introduction to contentious probate and our guide on the grounds for contesting a will. For costs, see our guide on costs in contentious probate. For time limits, see our guide on time limits for contesting a will. For mediation, see our guide on mediation in estate disputes. For Inheritance Act claims, see our guide on Inheritance Act 1975 claims.

For the non-contentious probate process, see our complete UK probate guide and our estate administration checklist.

Get started with Farra for help with the non-contentious estate administration.