Does dementia make a will invalid?

13 June 2013

This was the question that the High Court recently considered in the case of Simon v Byford (and others) [2013] EWHC 1490 (Ch).


Mrs Simon died in 2009, aged 91. Her son Robert brought a claim challenging the validity of her will on the grounds that his mother had, by the time she executed it in 2005, lost testamentary capacity, due to the onset of mild to moderate dementia.

Mrs Simon, a widow, had four children; Robert, Jonathan, Hilary and David. Her son David died in 2004. She made a will in 1996, in which she left to Robert a flat she owned in Essex and 16 shares in the family company founded by her late husband. The remainder of her estate was to be divided equally between her four children, subject to a legacy of £20,000 to her long serving house keeper.

In December 2005, the family held an 88th birthday party for Mrs Simon, which had been a tradition for some years. Hilary and Jonathan and other members of their family and friends attended, but Robert did not. It was at this party that Mrs Simon said she wanted to change her will to benefit her four children equally. A new will was drawn up with the help of Hilary’s husband, which split Mrs Simon’s estate between her children in equal shares, subject to the legacy as before to her house keeper. This new will was duly executed by Mrs Simon and witnessed by friends of Jonathan and Hilary.

This had the effect of taking from Robert his sole right to the flat and the company shares. Robert claimed that the 2005 will was invalid because his mother was suffering from mild to moderate dementia at the time, and she therefore lacked the necessary testamentary capacity to make a valid will. Robert and Hilary did not get on well, and Robert claimed that Hilary and Jonathan’s conduct had been sinister and reprehensible in facilitating the execution of the new will.

The Decision

The judge, Nicholas Strauss QC, rejected Robert’s claim. Evidence was heard that Mrs Simon had wished to benefit Robert in the 1996 will in order to ‘level up’ things between the four children; at that time, as managing director Robert had been mainly responsible for the success of the family company and Mrs Simon had previously assisted her other children financially. However, in earlier wills in 1978 and 1992 Mrs Simon had split her estate equally between her children, and by 2005 she wished to restore this arrangement.

It was common ground between the experts that by December 2005 “Mrs Simon was suffering from mild to moderate dementia, of such a degree as to put her testamentary capacity as at that date in doubt”. However, the judge found on the facts that Mrs Simon was capable of understanding the nature and effect of the will, that she understood her existing will did not favour her four children equally, and that she wished to execute a will that did benefit her four children equally.

The judge also found that although Mrs Simon was “not capable of remembering her reasons for preferring Robert in her previous will, or its terms”, the law supports the right of elderly people to leave their property as they choose, “even if their mental faculties are far from being at their peak”. This had to include many cases where the executor could no longer remember all the circumstances relevant to the division of their property and it would be “inconsistent with the case law” to make this a qualification for testamentary capacity.

The judge highlighted a number of important factors that were relevant in the circumstances of this case. The will was straightforward and “very simple” and the differences between the 2005 will and the previous one were “slight”. Also, “the beneficiaries under both wills were the obvious ones, and all received substantial gifts under both wills. Nobody was omitted”.


This case acts as a reminder that the concept of testamentary capacity that the courts are concerned with is not necessarily the same as most people’s normal understanding of capacity. When assessing testamentary capacity the court will consider the specific facts of the case, and in particular must be satisfied that the three part test for capacity laid down in Banks v Goodfellow (1870) has been met. This test is explained in more detail in Ryan Mowat’s recent blog Invalid Wills – the challenge of proving lack of ‘testamentary capacity’.

As these cases show, it follows that a testator is potentially capable of having testamentary capacity one day, but not the next. Factors relevant to the assessment of testamentary capacity will include the complexity of the estate, the nature of the assets, and the number and identity of the beneficiaries.

It is clear that the courts will not set a will aside on the grounds of lack of testamentary capacity lightly. Where a question arises over whether a deceased’s will reflects their testamentary intentions, it will often be easier to pursue a claim based on the grounds of ‘want of knowledge and approval’. However, where there is a risk that capacity may be an issue (for example if a testator is suffering from dementia of any degree) it would be prudent for those involved in making the will to engage a medical practitioner to verify the testator’s capacity at the point of execution of the will. Similarly, lawyers involved in the preparation of wills should always make a detailed note, which can be used to demonstrate that they have satisfied themselves that the appropriate test for assessing testamentary capacity has been met.

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