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  • Writer's pictureMelanie Palmer

Understanding the Implications of Lack of Capacity in Will-Making

Drafting a will is a crucial step in estate planning, ensuring that one's wishes are respected and executed after their passing. However, the process is governed by strict legal requirements, one of which is the willmaker's capacity. Capacity, in this context, refers to the willmaker's mental ability to understand the nature and implications of creating a will. When a willmaker lacks this capacity, it can lead to significant legal challenges and potentially invalidate the will. In this blog post, we'll explore what happens when a willmaker does not have the capacity to make a will and the potential consequences for their estate.

Elderly gentleman with a doctor
Ensuring capacity is very important when making a Will
What Constitutes Capacity?

To have the capacity to make a will, a person must meet several criteria:

  1. Understanding the Nature of the Will: The willmaker must comprehend that they are creating a document that dictates how their assets will be distributed upon their death.

  2. Knowledge of Assets and Beneficiaries: They must have a clear understanding of their estate's value and the individuals or entities who will benefit from it.

  3. Appreciation of the Act's Consequences: The willmaker should recognize the impact of the will's provisions and any decisions made within the document.

  4. Freedom from Delusions: They must not be suffering from any mental illness or delusions that influence their decisions regarding the will.

Indicators of Lack of Capacity

Several signs might indicate a lack of capacity, such as:

  • Cognitive Decline: Conditions like dementia or Alzheimer's disease that impair memory and decision-making abilities.

  • Psychiatric Illness: Severe depression, schizophrenia, or other mental health issues that affect rational thinking.

  • Influence of Medications: Certain medications can impair judgment and cognitive functions.

Legal Implications

When a willmaker is suspected of lacking capacity, it can lead to several legal issues:

Contesting the Will

If beneficiaries or other interested parties believe the willmaker lacked capacity, they can contest the will. Contesting a will involves legal proceedings to determine the validity of the document, potentially leading to its annulment.

Probate Court's Role

The probate court will examine evidence, such as medical records, witness testimonies, and expert evaluations, to determine the willmaker's capacity at the time of the will's creation. If the court finds a lack of capacity, the will may be declared invalid.

Intestate Succession

When a will is invalidated due to lack of capacity, the estate may be subject to intestate succession laws. These laws dictate how assets are distributed when there is no valid will, often resulting in a distribution that may not align with the willmaker's original intentions.

Appointment of a Guardian or Conservator

In cases where the willmaker's lack of capacity is ongoing, a court may appoint a guardian or conservator to manage their affairs, including estate planning decisions. This ensures the willmaker's best interests are protected, but it also removes their autonomy in these matters.

Preventative Measures

To mitigate the risk of capacity challenges, several steps can be taken:

  1. Early Planning: Encourage willmakers to draft their wills while they are in good health and free from cognitive impairments.

  2. Medical Assessments: Obtain a medical evaluation to document the willmaker's mental state at the time of the will's creation.

  3. Legal Advice: Engage an experienced attorney to oversee the will-making process, ensuring all legal requirements are met.

  4. Detailed Documentation: Keep thorough records of the willmaker's intentions, discussions, and decisions to provide clear evidence of capacity.


The capacity to make a will is a cornerstone of valid estate planning. Without it, the will's integrity can be challenged, leading to legal disputes and unintended distribution of assets. At Palmer Legal, we understand the complexities of estate planning and are here to guide you through the process, ensuring your wishes are clearly articulated and legally sound. If you have any concerns about capacity or need assistance in drafting a will, please contact us for expert advice and support.

Palmer Legal: Your trusted partner in comprehensive estate planning and legal services.

Melanie Palmer

Legal Practice Director

02 4869 1392


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