When can a will be challenged for lack of capacity?

Capacity is both time-specific and task-specific. Someone with cognitive impairment may still experience a “lucid interval” during which they fully understand the decisions they are making and can validly give instructions for a will. For that reason, a medical diagnosis alone is not enough to invalidate a will.

Similarly, a will cannot be challenged simply because its contents are unexpected or appear unfair. The court is not concerned with whether a will is fair, but whether it reflects the testator’s genuine intentions, made with the required mental capacity.

Evidence is crucial 

Anyone challenging a will must produce clear and credible evidence that the testator lacked capacity when the will was made.

This may include medical records from around the time the will was executed, evidence from the treating doctor or another medical expert, and records showing cognitive impairment or confusion. Witness evidence from people who had regular contact with the testator at the relevant time can also be important.

The solicitor who prepared the will will often play a significant role in any dispute.

Solicitors have a professional duty to satisfy themselves that a client has the necessary capacity before taking instructions. Evidence the solicitor met the testator, took instructions directly and concluded they understood what they were doing can carry considerable weight.

Where there are known concerns about capacity, a solicitor may also obtain a medical opinion or keep detailed attendance notes to support the validity of the will.

The court’s assessment 

The court will consider all of the available evidence together. Capacity is ultimately a legal question rather than a purely medical one and is not determined solely by a diagnosis.

Given the strong presumption that a properly executed will is valid, and the weight often attached to the evidence of the solicitor who prepared it, the court will generally be slow to set aside a will unless there is convincing evidence the testator lacked capacity.

If you are considering bringing a challenge, you should seek legal advice as early as possible. A solicitor can assess the available evidence, consider the surrounding circumstances and advise whether there are reasonable grounds to proceed.

In summary, while a will can be challenged on the grounds of lack of testamentary capacity, success depends on producing clear evidence the testator did not have the necessary understanding when the will was executed. Illness, advancing age or dissatisfaction with the contents of the will, on their own, are unlikely to be enough.

Alex Krupa LLB specialises in Family Law, Enduring Power of Attorney and Applications in respect of Mental Capacity and Assisted Decision Making and is a solicitor practising in Walsh & Partners Solicitors LLP, 88 Main Street, Midleton, Co Cork.