Testamentary capacity

An overview of the law surrounding the issue of capacity in the context of making a Will – so-called testamentary capacity.


There are several requirements for a Will to be valid, one of which is that the person making it (known as the ‘testator’) had the mental capacity to do so.

This briefing note will give an overview of the law surrounding the issue of capacity in the context of making a Will – so-called testamentary capacity.

What is testamentary capacity?

Testamentary capacity essentially means that the testator knew what they were doing when they made the Will.  However, there are several elements within this, which were set out in the important case of Banks v Goodfellow.

The testator must:

  • understand the nature of making a Will;
  • understand the extent of their property;
  • appreciate who might have a claim to their estate; and
  • not be suffering from any disorder of the mind or delusion.

The Mental Capacity Act 2005 also applies to assessing whether a person has capacity.  This states that a person lacks capacity in relation to a matter if “he is unable to make a decision for himself in relation to that matter because of some impairment of or a disturbance in the functioning of the mind or brain”.  However this does not replace the test set out in case law in relation to testamentary capacity.

At what time is capacity important?

The general rule is that the testator must have capacity at the time they execute the Will. 

Case law does however allow for a Will to still be valid if the person had capacity when they gave instructions for the Will, but subsequently had lost capacity when it was executed.  This applies where the Will is drafted in accordance with the instructions given at a time when the testator has capacity, and the testator recalls giving those instructions and can understand they are executing a Will, even if they do not remember the exact terms or do not understand the contents of the Will when it is read out to them.  This is the so-called Parker v Felgate rule after a case of that name.

Challenging a Will for lack of capacity

There is a presumption that a person is competent with capacity and therefore anyone seeking to challenge the Will on this basis has to provide evidence which would suggest otherwise.  For example, this may be medical evidence that the testator did not have capacity due to some illness they were suffering from.

If a person can provide sufficient evidence to cast doubt on the testator’s capacity, it is then for the person who is seeking to rely on the Will to prove the testator did in fact have capacity.

Where a Will was prepared by and witnessed by a solicitor or medical professional it will generally be more difficult to raise a challenge based upon capacity.


As outlined above, a Will may be challenged if it is believed the testator did not have the requisite mental capacity at the relevant time.  We also have guidance notes relating to execution of Wills, undue influence and want of knowledge and approval which may also be useful to you.

If you believe the issues raised in this briefing note may be relevant to you, please contact us for further advice.

Our content explained

Every piece of content we create is correct on the date it’s published but please don’t rely on it as legal advice. If you’d like to speak to us about your own legal requirements, please contact one of our expert lawyers.

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