Testamentary capacity in the Republic of Ireland

Assessing a patient's capacity is essential for all doctors and there are medico-legal considerations. Here’s what you need to know.

  • The Succession Act 1965 says that in order to make a will, the person doing so (the testator) must be "of sound disposing mind".
  • Most wills are made without an assessment of the testator's mental capacity.
  • However, in cases where there is any doubt, a doctor can be asked to conduct a formal assessment of a patient's testamentary capacity.

Legal test

The legal test of testamentary capacity was established in 1870 in the English case Banks v Goodfellow1.

A man with probable schizophrenia left his sizeable estate to his teenage niece, but the will was challenged by an overlooked relative.

The judge in that case ruled that in order to have testamentary capacity, a testator must be capable of understanding:

  • the nature of the act of making a will and its effects
  • the extent of their estate
  • the claims of those who might expect to benefit from the will.

As well as this, the testator must not have a mental illness that would influence them to make bequests they would not otherwise have made.

Doctors' considerations

If you are asked to assess a patient's testamentary capacity, you should first consider the following points.

  • If you have the relevant experience and expertise to conduct such an assessment.
  • If not, you should not undertake the assessment, and should explain this to the patient or solicitor who has requested the assessment.
  • If you have adequate information about the extent of the estate and all of the people who might expect to benefit from the will, and those who are benefitting from the will.
  • This information should not be obtained from the patient themselves. You will need to obtain a corroborative history from another person with access to this information (such as the patient's solicitor) and you should ask for this information in writing in advance of your assessment. It is perfectly reasonable also to ask for copies of any previous wills, and it's also okay to ask about the patients' assets.
  • If you have a good understanding of the legal test applied.
  • You should familiarise yourself with the Banks v Goodfellow ruling.
  • Ensure that the patient is not under any undue influence.

If you decide to proceed with the assessment, you should conduct this as close as possible to the time the will is made.

MDU advice

You should be aware that your opinion on the patient's testamentary capacity may be challenged, and that such challenges can arise many years after your assessment and can be pursued vigorously. You might therefore wish to consider the following advice.

  • Set aside adequate time to conduct a full assessment.
  • Record the names of everyone present and consider their reasons for being present.
  • Do not conduct your assessment in the presence of anyone who might influence the patient's answers.
  • First decide whether the patient has a mental illness that would influence them to make bequests they would not have done otherwise. If they do not, ask the patient questions to obtain answers that will satisfy the legal conditions set out in the Banks v Goodfellow ruling.
  • Specifically ask why any person who might reasonably expect to benefit from the will is excluded and why any person who might not be expected to benefit from the will is included.
  • Make detailed records about your assessment.
  • Record verbatim the answers to the most important questions.
  • If, following your assessment, there is any doubt about whether the patient has testamentary capacity, refer the patient to another doctor with particular expertise in the assessment of capacity.

Assessments of testamentary capacity can be difficult and finely balanced. Determining whether a patient who acts unexpectedly when they are making their will has capacity and is simply acting according to their wishes, or is in the early stages of a mental illness or cognitive decline that is influencing their decisions, can be extremely demanding.

If in doubt, doctors should always ask a colleague with a special interest in the assessment of mental capacity for a second opinion.

If you would like to speak to one of the MDU's medico-legal advisers about consent, capacity, or any related issues, contact us here.


1 Banks v Goodfellow (1870) LR 5 QB 549 (ratified in: In the estate of Brian Rhatigan [2010] IEHC 475, [2011] 1 IR 639)

This page was correct at publication on 15/03/2021. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.