When is Someone Too Ill to Make a Will?


Dementia, among other disorders and diseases, can highlight huge challenges for both doctors and lawyers when assessing the testamentary capacity of a person when preparing their Will. The current UK law requires a person to fully understand what they are doing and the implications of such decisions. But what processes are used to ensure that somebody is mentally sound enough to make a Will? We take a look at the matters that may be called upon to determine if somebody is too ill to make a Will.​

Dementia describes a variety of brain disorders and one of the most common types is Alzheimer’s. Other types are Dementia with Lewy Bodies (involving Parkinson’s Disease) and Vascular Dementia. Symptoms include memory loss, confusion and problems with speech and understanding. There is no known cure. According to the Alzheimer’s Society and research, there are 850,000 people with Dementia in the UK, with numbers set to rise to over 1 million by 2025.

For an individual to prepare their Will and to freely express to whom their property and possessions should be left, there are two tests that may be applied. Banks v Goodfellow (1870) remains the leading case and assessment. To exercise the creation of a Will the testator (being the person making a Will) must understand: 

  • The nature of the act and its effects. This includes the act of making a Will, the method of revocation and the rationale behind the appointment of Executors (being the persons appointed to carry out the terms of the will) and the effect of any Beneficiaries (those receiving the possessions or assets) predeceasing them.
  • To understand the extent of the property to which they are disposing – this is interpreted in a broad brush way with no requirement for the testator to compile a mental inventory of all assets.
  • Whether the testator was able to comprehend and appreciate the claim to which they ought to give effect: it is not necessary for a testator to make provision for all the persons who may have a claim on their Estate, and determine whether or not they are able to benefit.
  • Whether the testator was subject to an insane delusion that would influence their Will – much would depend upon the form of delusion and whether it affected the manner in which the testator disposes of their property.
  • The Banks v Goodfellow test must be met at the time when instructions for the Will are given and when the Will is executed. The rule in Parker v Felgate applies where the individual would still be required to be capable of understanding that he was engaged in the execution of a Will for which he had previously given instructions at a time when he was of sound mind and continued to appreciate the act of executing his will. The case itself, however, involved a testator who was unable to remember instructions previously given and his signature affixed by another person on his behalf, thereby making the will invalid.

The second test is the Mental Capacity Act 2005. The Act does not dispense with the common law test in Banks v Goodfellow or its authorities. In Scammell v Farmer (2008) the court held that the test for capacity set out in the Act does not apply in probate claims about testamentary capacity. The Act nevertheless cannot be ignored. The MCA provides that it is assumed a person has capacity until the contrary is proved, and a person will lack capacity if at the material time he is unable to make a decision for himself due to an impairment or disturbance of the mind, whether permanent or temporary.


This is never easy. A mild form of Dementia may suggest the testator has and retains capacity and a moderate severity may provide for periodic lucid intervals. Testing for capacity can involve Mini-Mental State Examination (MMSE) tests, but the scores themselves can frequently be open to different interpretation. 


An experienced solicitor will always take instructions for a Will face to face and generally with no one else present. Open questions and proper dialogue will enable the solicitor to gauge the testamentary capacity. For an aged or seriously ill testator, it is open for the Solicitor to engage “the golden rule”. This is a recommendation for a solicitor to obtain an Expert Report or a Report from a medical practitioner familiar with the testator and where appropriate have the medical adviser witness the Will. Unfortunately, the practice is rarely followed, frequently due to the lack of ability of a GP or timing issues. Although a Court may be slow to sanction Solicitors who do not follow the rule it can on occasion open the door for individuals to contest validity.

A testator who may be at risk of a future disputed Will claim may be best served by obtaining an Expert Report at the time that the Will is prepared. This can be far more effective than a retrospective Report. The more straightforward a Testator’s Will is the easier it is to satisfy a Court on capacity. No testator should be unduly concerned if their solicitor advises on the preparation of a Medical Report where it is intended to protect and validate the testamentary wishes of the individual.

The golden rule is a rule of solicitors good practice, not a rule of law. The opinion of a general practitioner, unimpeachable in itself and supported by that of one or more solicitors, may nevertheless very occasionally be shown by other evidence to be wrong. However, where professional people reach a properly informed and recorded conclusion that a testator does have testamentary capacity, it will require very persuasive evidence to dislodge that conclusion; Sharp and Another v Adam and Another (2006).


If you feel that you require further legal advice relating to the creation or validity of a Will of someone who is considered mentally incapacitated, it is recommended that you seek legal advice. We have an experienced and dedicated team of specialist Wills solicitors based in our offices across Essex and London. We have evening and weekend appointments available for clients that find it difficult to arrange meetings during working hours.


The contents of this article are for the purposes of general awareness only. They do not purport to constitute legal or professional advice. The law may have changed since this article was published. Readers should not act on the basis of the information included and should take appropriate professional advice upon their own particular circumstances.


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