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Testamentary capacity explained

One of the essential requirements for a Will to be valid is that the person making it (the testator) must have testamentary capacity. This means that the testator must have sufficient mental capacity to make a Will. If a Will is rational on its face, and correctly signed in front of witnesses, it will be presumed that the testator had testamentary capacity. In these circumstances anyone disputing the Will on capacity grounds will need to show that the testator did not have testamentary capacity.

The test for whether an individual has the testamentary capacity to carry out a particular action is task specific. This means that the requirements can differ, depending on the action being considered, with more complicated tasks requiring a higher level of capacity.

The test of capacity to make a Will

To have testamentary capacity a testator must understand:

  • the nature of a Will and its effects,
  • the extent of his or her property, and
  • the moral obligations that he or she ought to consider. This includes distinguishing between individuals and reaching a moral judgment, such as whether one child should be preferred over other children, because they are less well provided for, more deserving, or in need of greater financial assistance due to family responsibilities or their state of health;
  • and have no disorder of the mind that perverts their sense of right or prevents the exercise of their natural faculties in disposing of their property by will.

It is not necessary that the testator remembers details without prompting. In one case the judge reiterated that capacity depends on the potential to understand these matters. It was irrelevant that the testator had forgotten she owned a particular asset until reminded, just that when reminded she understood that she owned it.

Similarly, capacity does not require understanding of the collateral consequences of making a Will. In the same case, the testator did not appreciate that equally gifting her shares in the family company to her children could potentially lead to deadlock over decisions. However, this did not affect the fact that she understood  she owned the shares, appreciated the claims of her children and formulated the desire to leave the shares to the children equally, which she understood her Will achieved. Therefore, in the eyes of the law, she had capacity to make the Will, even though she did not appreciate the ramifications of leaving the shares equally.

The burden of proof

When it comes to making a Will the test for capacity should be based ‘on the balance of probabilities’. In other words, is it more likely that the individual is capable or incapable?  The person undertaking the test, typically the individual’s GP or consultant or another medical professional, does not need to be satisfied ‘beyond reasonable doubt’.

Medical evidence can be crucial in establishing capacity. The so-called “golden rule” for practitioners is that, in preparing a Will for a very elderly or seriously ill testator, contemporaneous, written medical evidence as to capacity should be obtained, so it can be produced if any later claim as to lack of capacity is made. Although, in one case it was stated that strong evidence of incapacity would be required, when an experienced solicitor had formed the opinion that the testator had capacity and had recorded this contemporaneously in writing.

If the individual does not have testamentary capacity

If the individual is deemed not have mental capacity the Will will be invalid and either their previous Will will determine the distribution of their estate or, if they do not have a previous Will, the rules of intestacy will decide how their estate is divided.

Many contentious probate cases involve allegations that a testator did not have testamentary capacity, often twinned with allegations that the testator did not know and approve of the Will’s contents, which is another vital component for a valid Will.

Contact a solicitor

Our private client team specialise in advising families on issues related to mental capacity.  Contact us for a free and confidential initial consultation. We have specialist lawyers in London, Manchester, Bristol, Cardiff, Birmingham, Southampton and Taunton. Call us now on 0800 652 8025 or contact us online.


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Carol Cummins


Carol enjoys long term relationships with her clients and likes to get to know the families well so that she can help them at each key step in life with a focus on protecting the family wealth from erosion by tax and outside claims so it remains in the family for future generations.
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