In 2026 the link between probate law and cognitive health has become a critical focal point for legal practitioners in Northern Ireland. There are currently 25,000 people living with dementia in Northern Ireland. As life expectancy increases and the prevalence of dementia rises, the Northern Ireland High Court is tasked with determining the validity of Wills created by individuals with wavering mental capacity.
The legal test for testamentary capacity in Northern Ireland comes from the landmark 1870 case, Banks V Goodfellow. To have the capacity to make a Will, a person must satisfy four specific limbs: Nature of the Act: the individual must understand they are making a will and what its consequences are. Extent of the property: the individual must have a general idea of the size and nature of their estate. Moral claims: the individual must be able to appreciate the claims of people who might expect to inherit (e.g. children or spouses), even if they chose to exclude them Freedom from delusion: the individual must not be suffering from any disorder of the mind that poisons their affections or perverts their sense of right. If an individual is diagnosed with dementia, they can still make a will.
The court recognizes that individuals with dementia will experience times when the cognitive function is sufficient to satisfy the above threshold. However, as dementia progresses the fourth limb of the criteria of Banks V Goodfellow often becomes contentious. A recent ruling in an England and Wales, Ginger V Mickleburgh [2026] has clarified that even if a will appears rational, it can still be overturned if it can be proven that the testator suffered delusions which influenced the distribution of assets. With the rise of contested probate, solicitors are increasingly relying on practice directions and guidelines. There is a best practice guideline that suggests when an individual is elderly or ill the will should be witnessed or approved by a medical practitioner who has formally assessed their capacity.
This can safeguard the individual’s will from being contested in the future. When an individual has lost their capacity to make a will, the Mental Capacity Act (Northern Ireland) 2016 provides a safeguard. Through the office of care and protection, an application can be made for a statutory will on their behalf which is approved by the court. If a family member or loved one has been diagnosed with dementia it is important to prepare for the future, McCay Legal can help you with this. Contact us on, Tel; 02871 371705.
Written By Associate, Mia Fox
