Challenging a will on grounds of mental capacity will inevitably mean considering the golden rule

3 Key Points about the Golden Rule

If you’re worried about the contents of a will and believe the person who made it was showing signs of dementia or mental vulnerability, it is well worth checking whether the solicitor who made the will followed the Golden Rule.

What is the Golden Rule?

The Golden Rule is an obligation for the solicitor preparing a will to ensure that the testator has sufficient mental capacity when the will is made. Furthermore, the Golden Rule applies to situations where the solicitor has reason to doubt whether the testator is of sufficiently sound mind to make a valid will. This could arise, for example, if a testator has exhibited erratic behaviour, or if an elderly testator is showing signs of dementia.

The Golden Rule means that solicitors are generally expected to obtain a documented assessment from a medical professional as to whether or not the individual making the will has testamentary capacity when the will is made. This obligation was established in Kenwood v Adams [1975] CLY 3591 and later confirmed in Re Simpson [1977] 121 SJ 224.

Build a strong case supporting your will dispute claim

In the absence of the relevant medical examination, claimants can build a stronger case for a will dispute on grounds of lack of testamentary capacity. As well as leading to a potential will dispute, professional problems can arise for solicitors who have failed to take the necessary precautions required by the Golden Rule. Three key points about the Golden Rule are set out below.


  1. Understanding Testamentary Capacity

The requirements for an individual to have testamentary capacity are set out in Banks v Goodfellow (1870-71) L.R. 11 Eq. 472:

  • The testator must understand what assets they are leaving in the will. This requires a general knowledge of what property they own, their money, shares and other investments.
  • The testator must know or understand the nature of the document they are signing. The testator must know they are creating their will and understand the effect of the decisions set out in the will. They must understand that the will determines how their property will be divided up after they die, and whom will benefit by how much under this particular will.
  • The testator must also know who their dependants are, and have an awareness of which people they are obligated, morally or through family ties, to include as beneficiaries of the will. This provision can be complicated in cases where the testator’s memory is compromised, for example by dementia.


  1. Obtaining Evidence

When challenging a will on grounds of lack of testamentary capacity, it is important to gather evidence that the testator did not have testamentary capacity at the time the will was created.  Examples of evidence that could strengthen your claim include:

  • Medical evidence such as hospital records
  • Statements from friends and family of the testator who can describe the testator’s state of mind when the will was signed
  • Emails, letters or other documented communications of the testator around the time the will was made.


  1. An Uncomfortable Conversation

For a solicitor preparing a will, following the Golden Rule is potentially uncomfortable, as it involves suggesting to a testator that they have their mental capacity assessed by a medical professional. However, this does not absolve the solicitor of the responsibility to ensure that wills they prepare are signed by an individual with testamentary capacity, and are therefore valid. The risks involved in failing to assess the mental capacity of a testator are great enough that in many cases, it is worth the discomfort of suggesting a medical evaluation.


Following the Golden Rule by obtaining a documented medical assessment of a testator’s mental state, is a responsible way for a solicitor to avoid a will dispute. However, it is important to note that for someone challenging a will, the fact that a solicitor has not followed the Golden Rule, does not guarantee a successful claim of lack of testamentary capacity. A court might find that the testator did indeed have testamentary capacity, even if the solicitor failed to obtain a medical examination when the will was made. Therefore, in a will dispute over testamentary capacity, regardless of adherence to the Golden Rule, it remains important to gather strong evidence that the testator did not satisfy the conditions for capacity set out in Banks v Goodfellow.