Making a will is a personal legal act. A family member cannot simply write or sign a will on behalf of another person because they believe it reflects what that person would have wanted.
The person's capacity to make a will is therefore extremely important.
What is testamentary capacity?
Testamentary capacity refers to the mental ability required to make a valid will.
HMRC guidance referring to the established legal test states that the person making the will must understand that the document will operate after their death, understand the broad effect of what they are doing, have an understanding of the property being disposed of and understand the people who may have claims on their estate.
Does an illness automatically mean someone lacks capacity?
No.
A diagnosis or physical illness does not automatically mean that a person lacks testamentary capacity.
The important question is whether the person has the necessary understanding at the relevant time.
GOV.UK also explains that someone who has lost mental capacity to manage their finances may still have the ability to make a will.
What if someone cannot make a will themselves?
If a person cannot make or change a will themselves, an application can be made to the Court of Protection for a statutory will.
The Court of Protection can authorise a will or changes to an existing will where the person is unable to make the decision themselves.
The application process can involve evidence about the person's circumstances, their existing will, their assets and the proposed arrangements.
Why can capacity become a legal issue?
Capacity disputes can arise after someone's death.
For example, family members might question a will where:
It was made shortly before death
The person was seriously unwell
The will made significant changes
A beneficiary became substantially better off
Someone else was heavily involved in preparing the document
These circumstances do not automatically make a will invalid, but they may require careful examination.
What can help reduce future disputes?
Where there may be concerns about capacity, proper will preparation and evidence can be particularly important.
A professional will-making process can help establish what the person understood and whether the instructions genuinely came from them.
Conclusion
You cannot simply make a normal will for another adult because they are elderly, ill or unable to manage their affairs.
If someone lacks the capacity to make a will, the appropriate route may involve the Court of Protection and a statutory will.