The Power of One – Mental Capacity and the Right to Make One’s Own Decisions | Wills

October 7 , 2014
October 7 , 2014

The Power of One – Mental Capacity and the Right to Make One’s Own Decisions | Wills

The Power of One – Mental Capacity and the Right to Make One’s Own Decisions | Wills

The issue of mental capacity can be a minefield for both lawyers and families alike.  For a solicitor to inform a client that they will need to verify, via a medical professional, whether they (the client) has the mental capability to make legal decisions that affect their person or property requires both sensitivity and responsibility to ensure that the client’s interests are properly protected.  The issue of mental capacity can incorporate many scenarios, however, the one most of us are familiar with is testamentary capacity with regards to making a Will.

This blog will highlight the various scenarios where a lawyer must decide whether a client has the mental capability to make decisions.  I will be discussing Wills in depth and I will also mention other situations where mental capacity may need to be evaluated before client instructions can continue.


The issue of whether a person has the mental capacity to make a Will is a highly emotive one for all parties.  If a family member challenges a Will on the grounds of testamentary incapacity then they do so knowing that they are challenging the final wishes of a loved one.  Equally, however, sometimes it may be clear that the person who made the Will lacked the mental capacity to fully comprehend what they were doing and it would be unjust not to correct the situation.

So what is testamentary capacity and how does it affect the validity of a person’s Will?  And if testamentary capacity is found to have been lacking, can the original Will be amended and who makes the decision as to how the amendment is done?

What is Testamentary Capacity?

Testamentary capacity is the legal term used to describe that an individual had the mental and legal capability to make a valid Will at the time it was signed.

In law, it is presumed that all people over the age of 18 years have testamentary capacity.  It is therefore for the individual challenging the Will to rebut this presumption with sufficient evidence.  If the presumption is successfully rebutted it is then up to the executor of the Will to prove that the Will-maker had mental capacity at the time the Will was signed and witnessed.

The test for assessing whether or not a person has the mental competency to make a valid Will was established in the case of Banks v Goodfellow (1870).  To have capacity the testator must:

  • Understand the nature and effect of making a Will;
  • Understand the extent of the property of which he or she are disposing;
  • Be able to comprehend and appreciate the individuals who should have a claim to his or her property under the Will; and
  • Have no disorder of the mind that perverts his or her sense of right or prevents the exercise of his or her natural faculties in the disposing of property via a Will.

The Golden Rule

If a Will is signed and witnessed in front of a lawyer, would this not be enough to satisfy that the testator had testamentary capacity?  The answer is no, and a legal professional has an obligation to follow the ‘golden rule’ when it comes to dealing with elderly clients, which was set out in the case of Kenward v. Adams (1975) and it is worth quoting Templeman J’s words in full:

“In the case of an aged testator or a testator who has suffered a serious illness, there is one golden rule which should always be observed, however straightforward matters may appear, and however difficult or tactless it may be to suggest that precautions be taken: the making of a Will by such a testator ought to be witnessed or approved by a medical            practitioner who satisfies himself of the capacity and understanding of the testator, and       records and preserves his examination and finding.”

Therefore, the first question anyone challenging a Will should ask is whether the solicitor involved had a certified medical practitioner to assess the testator.

If I Believe that the Testator Lacked Mental Capacity or was Unduly Influenced When Making Their Will How Can I Challenge the Will’s Validity?

The first thing to be aware of is that challenging a Will on these grounds is expensive, emotionally difficult and notoriously hard to prove.

Undue Influence

The courts invoke a high threshold when deciding what amounts to undue influence.  For the court to be able to find that the testator was unduly influenced into doing something he or she would not normally have done an element of coercion must be present (Wingrove v Wingrove (1885). There must be solid evidence that the coercion, which can be either physical or psychological, took place.

Cases where undue influence has been proved successfully are extremely rare.  In 2011 one claimant did succeed in the case of Schrader v Schrader (2013).  The claimant and defendant were brothers and unbeknown to the claimant the brothers’ Mother had left her entire farm to the defendant.  It later emerged that the defendant knew of this situation and lied about this knowledge in court.  He was also unable to explain why his Mother changed her Will to make him the sole beneficiary.  This, along with his proven lack of credibility, led the court to conclude that coercion must have occurred.

Mental Incapacity

Mental incapacity can be just as hard to prove as undue influence and it is essential that you obtain expert legal advice before commencing with proceedings.

The Mental Capacity Act 2005 (which will be discussed in detail further on) provides statutory reference on how to test mental capacity, however, the statute does not specifically concern itself with the execution of a Will.  Nevertheless, the courts are likely to develop the existing common law to fall in line with the statutory provisions.  Like the common law, there is a presumption under the Act that a person has mental capacity unless proven otherwise.  Section 3 states that a person who has mental capacity should be able to:

  • Understand information relevant to the decision they need to make;
  • Be able to retain that information;
  • Be able to use this information to make an informed decision; and
  • Be able to communicate their decision (not necessarily by talking).

If you wish to challenge the validity of a person’s Will on the grounds of mental capacity you will need to provide strong evidence from a medical professional and/or other witnesses who had met the deceased.  In the 2013 case of Hawes v Burgess LJ Mummery stated that a Will drafted by a lawyer  “should only be set aside on the clearest evidence of lack of mental capacity”.

If the court decides that the testator did lack mental capacity or was unduly influenced the Will may be set aside.

What Happens to the Testator’s Estate if Their Will is Deemed Invalid Due to Lack of Capacity or Undue Influence?

If a Will is declared invalid then the deceased will be treated as though they died intestate (without a Will) and their property will be divided according to the laws of intestacy.  As I have discussed in a previous post, this can often mean some family members miss out on their inheritance and the division of the property may not reflect the wishes of the deceased at all.

A Deed of Variation

If some of the affected beneficiaries all agree, they can draw up a Deed of Variation.  This document allows the beneficiaries to change the distribution of the estate after the testator’s death.

A Deed of Variation is mainly used by beneficiaries wanting to avoid inheritance tax and pass on assets distributed to them in a Will to their children or other needy beneficiaries.  However, the deed can also be used by beneficiaries as an alternative to the expensive, and more often than not unsuccessful, quest of trying to prove undue influence or mental incapacity.  Beneficiaries can also use a Deed of Variation to redistribute assets if the original Will is declared invalid by the courts and the rules of intestacy are used to divide up the estate.

Not all beneficiaries have to agree to the division of a testator’s property under a Deed of Variation, as long as the beneficiary using the deed is varying only their share.

A deed of variation must be drawn up within two years of the testator’s death.

Other Situations Where Mental Capacity May Need to be Evaluated

The requirement for a solicitor to assess a client’s mental capacity can involve many situations other than the making of a Will.  For example, if a client with the onset of dementia wishes to transfer property, can they fully comprehend the instructions they are giving to their lawyer?  Or does a person with learning disabilities or severe depression qualify as lacking capacity?

The above scenarios are covered by the Mental Capacity Act 2005.  This Act is applicable to anyone who suffers from “an impairment of, or a disturbance in the functioning of, the mind or brain.”  This definition applies to both permanent and temporary afflictions to mental capacity.

Under the Act, if a person is found to lack capacity to make a necessary decision then another person can make the decision for them as long as they abide by the five core principles of the Act which are:

  1. Unless it is presumed otherwise there is a presumption of capacity;
  2. An attempt is made to try and assist the person who is required to make the decision to come to the decision themselves;
  3. Just because a decision is deemed unwise by others does not mean that a person lacks mental capacity;
  4. Any decisions or actions taken on behalf of the person found to lack mental capacity must be done in his or her best interests; and
  5. Any decision made should be the least restrictive option available.


Mental capacity is a contentious issue which must be handled by professionals with the utmost respect and consideration of the person affected.  Both legislation and common law provide vehicles to protect the vulnerable from decisions being made by other people who may not have the best interests of the decision-maker at heart.  However, it is telling that both legislation and common law both presume a person has the mental capacity to make their own decisions unless proven otherwise and set the bar high for this presumption to be changed.  This is because the ability to maintain control of our own lives lies at the heart of a person’s individual freedom, which should not be relinquished or taken away without sound reason.

If you would like to find out more about Wills please click here.

If you have any comments to make on testamentary capacity please feel free to enter them in the section below, we would welcome your thoughts.


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