Can I Contest A Will If The Person Didn’t Have Capacity?

by | Jan 6, 2026 | Contesting Wills, Estate Disputes NSW, Probate and Estate Administration, Wills and Estates

How to Contest a Will for Lack of Capacity in NSW

Wills Lawyers Penrith, Richmond, Macarthur

We are frequently asked the question of whether there is an ability to contest a will even before Probate is granted if there are concerns that the person who made the will did not have capacity.  In New South Wales. The short answer is yes, a will can be contested if the person making the will did not have capacity.  It will be up to the court to determine whether or not there was capacity, and this can be examined in several different ways.

What Is Testamentary Capacity And How Can I Challenge It?

The term testamentary capacity refers to the persons ability or mental ability to understand a will at the time that it is drafted and signed.  In these circumstances the person that has made the will and signed it must:

  • Understand the nature of making a will.
  • Understand the effect of their will on their property
  • Understand the advice given by their solicitor or at the time the will was drafted as to the extent of their property and other estate assets.
  • Understand who may be benefiting from their will and who they are appointing as executor.
  • Understand any potential claims based on the drafting of the will by persons who may be eligible to contest if they feel they have not been treated fairly.

Grounds For Challenging A Will In Relation To Capacity

There are many grounds to challenge a will, but specifically in relation to capacity, by far the most common case that we see at Rafton Family Lawyers is the issue of medical conditions or cognitive issues.   This generally refers to a class of matters where it is alleged the person was not of sound mind, memory, or simply would not have understood the nature and effect of the will once drafted.

In most circumstances, this relates to a will that has been updated, particularly later in life, but in some situations it can relate to the first will the person has ever drafted (although this is less common).

Effectively, a will can be challenged if there is an allegation that the Testator had some medical condition or cognitive decline that affected their ability to know and understand what they were signing.  This could relate to them having a lack of memory, understanding, or not being of sound mind.

Is There A Time Limit In Which To Challenge A Will?

Challenging a will under these circumstances, we normally recommend occurs before the Grant of Probate and most Grants of Probate are made within six months of the person dying.  However, you are not prevented from bringing an application to the court after that time period, however, we do recommend that you act quickly as once Probate is granted normally the executor is then able to distribute the estate and it can make it much more difficult to try to claw back or adjust assets after they have already been distributed.  It is important to seek legal advice very quickly after the person or your loved one dies.

Can Any One Challenge The Will For Capacity?

The short answer is no.  There are only certain persons who can challenge the will, and this includes:

  1. The person who is mentioned or noted in the will, such as a beneficiary.
  2. A person who believes they should have been included in the will but were not, such as a child or spouse of the deceased.
  3. A person who has a close relationship with the deceased and believes they have been unfairly excluded.  This particular class extends beyond immediate family and can include persons such as carers and, in some situations, also charities or bequests that have been made particularly in prior wills that are then updated once the person has advanced in age.

Are There Particular Conditions That Make Challenging A Will Easier?

In most court applications that we have been involved in, the challenge is generally made for a medical condition or cognitive decline and by far and away that relates to early onset dementia and/or an Alzheimer’s diagnosis.  These types of conditions generally indicate that there has been a medical or cognitive decline and in bringing the application to the court by the person challenging the will they will need to bring expert medical evidence in relation to that condition.  It is imperative therefore to seek advice from a specialist lawyer who understands exactly what expert documents are required.

There is also an ability to produce documents to the court that provide other independent evidence relating to cognitive decline and this could include the medical records at a treatment facility, a general practitioner’s medical records and medical records at a nursing home or care facility.  Once you provide instructions to your expert estate lawyer, they should be able to work together to obtain all of the necessary factual documents to prove the medical condition or cognitive decline.

These types of matters are not always challenged simply on the basis of a diagnosis of dementia. Other conditions that have been challenged can include chronic conditions that can affect capacity, such as Parkinson’s Disease and Motor Neurone Disease and other general health-related chronic conditions that usually affect older or elderly persons.

Does It Cost To Challenge A Will In NSW?

Yes.  All applications to the court do cost, and the cost relates to payment of legal fees to contest the will and also payment of a filing fee to the court when the application is commenced.  Costs for your solicitor will need to be fully disclosed at the commencement of your matter, and your solicitor should provide an estimate of those costs so that you can make an informed decision before proceeding or commencing the application.  It is also imperative to seek expert legal advice from somebody who practices in this area to ensure that you have reasonable prospects of success once your application is filed.  These are legally complex matters, and it’s important to receive the expert advice in a timely manner.

Contact our office for more information or to book a confidential one-off consultation to discuss your matter reception@rafton.com.au or (02) 8607 7184.

0