Capacity and Undue Influence: The Two Biggest Issues in Will Challenges
When families dispute a Will, two issues arise more than almost any other: testamentary capacity and undue influence.
These claims sit at the centre of many estate disputes in Queensland, particularly as Australia’s population ages and family structures become increasingly complex.
While people often assume a will can be challenged simply because it feels unfair, the legal reality is far more complicated. Successfully challenging a will usually requires evidence that something affected the validity of the document itself.
What Is Testamentary Capacity?
Testamentary capacity refers to a person’s legal ability to make a valid will.
In Queensland, a person making a will must understand:
the nature and effect of making a will,
the assets they own,
who may reasonably expect to benefit from their estate,
and the consequences of their decisions.
Importantly, capacity is not determined solely by age.
A common misconception is that elderly people or individuals diagnosed with dementia automatically lack the ability to make legal decisions. That is not necessarily true. Many people with early-stage dementia may still have sufficient understanding to make a valid will.
Capacity is also task-specific. Someone may be capable of managing everyday decisions while struggling with more complex legal or financial matters.
Because of this, estate planning lawyers often conduct detailed legal assessments when preparing wills, particularly where:
there are significant changes to previous wills,
children are being excluded,
assets are distributed unequally,
or concerns exist about cognitive decline.
In some situations, medical assessments from geriatricians or specialists may also be obtained to support the validity of the will.
Why Unequal Wills Raise Concerns
One of the biggest warning signs in estate disputes is a dramatic departure from what families expected.
For example, leaving an estate equally to children is generally considered low-risk from a litigation perspective. However, where one child is excluded or receives significantly less than others, the risk of future disputes increases substantially.
This does not mean unequal wills are invalid. People are entitled to make their own decisions about their estate. However, where significant changes occur later in life, questions often arise about whether the person truly understood the consequences of those decisions.
What Is Undue Influence?
Undue influence involves allegations that someone pressured, manipulated, or coerced a person into changing their will.
Examples may include:
isolating an elderly parent,
controlling access to finances or communication,
arranging legal appointments on their behalf,
or exerting pressure during periods of illness or vulnerability.
These claims are often emotionally charged and difficult to prove.
Courts generally require strong evidence of coercion rather than simple persuasion or family disagreement. Suspicion alone is rarely enough.
In many cases, allegations of undue influence are closely connected to concerns about capacity. A person experiencing cognitive decline may be more vulnerable to pressure from others, particularly where dependency or isolation exists.
Why Proper Estate Planning Matters
Careful estate planning can significantly reduce the likelihood of future disputes.
This may include:
obtaining professional legal advice,
documenting the reasons behind important decisions,
keeping detailed file notes,
and obtaining medical evidence where capacity may later be questioned.
Homemade wills, unexpected late-life changes, and poorly documented decisions often create fertile ground for litigation after someone passes away.
Final Thoughts
Will challenges are becoming increasingly common in Queensland, particularly where ageing, vulnerability, blended families, and significant assets intersect.
While every family situation is different, capacity and undue influence remain two of the most significant issues courts examine when determining whether a will is valid.
If you have concerns about a will or need guidance around estate disputes in Queensland, contact Lidia Vicca or book a free consultation through our website to discuss your circumstances and explore your options.