Can Someone With Dementia Make A Will?

Families often ask this question when dementia has been diagnosed and estate planning has not been finalised.

Can someone with dementia make a will?

The answer depends on whether the person still has the required capacity to make that specific will.

A dementia diagnosis does not automatically stop someone from making a will, but the person must understand what they are doing and the decision must reflect their own reliable wishes.

Short Answer

Yes, someone with dementia may be able to make a will if they still have testamentary capacity.

Testamentary capacity means the person understands they are making a will, broadly understands what they own, recognises who may have a claim on their estate and understands the effect of their decisions.

The key issue is not the diagnosis alone.

The key issue is whether the person’s decision-making is reliable enough for this specific legal decision.

Key Takeaway: Dementia does not automatically prevent someone from making a will. The important question is whether the person still understands the nature and consequences of the will they are making.

Dementia Does Not Automatically Invalidate A Will

A person can have dementia and still make a valid will if they have capacity at the time the will is made.

This matters because capacity is not based only on a diagnosis.

It is based on the person’s ability to understand the specific decision in front of them.

Someone in the early stages of dementia may still be able to give clear instructions, explain their wishes and understand the consequences of their choices.

However, if dementia has affected understanding, memory, reasoning or vulnerability to pressure, the will may later be questioned.

What Testamentary Capacity Means

Testamentary capacity is the specific type of capacity needed to make a will.

In practical terms, the person should generally understand:

that they are making a will
what a will does
the general nature of their assets
who may reasonably expect to benefit
how their decisions affect those people

This does not mean the person needs perfect memory or perfect legal knowledge.

But they do need enough understanding for the will to reflect their real wishes.

Decision Reliability Matters

With dementia, the question is not simply whether someone can say what they want once.

The deeper question is whether their decisions about assets, beneficiaries and consequences are still reliable enough for the will to reflect their true wishes.

A person may need more time or simpler explanations and still have capacity.

That is different from a person whose wishes keep changing without clear reasoning, who forgets important family relationships or who is easily influenced by whoever is present.

A useful OAP question is:

Are their decisions about the will consistent, understood and free from pressure?

What A Lawyer May Look For

A lawyer preparing a will may need to be satisfied that the person understands what they are doing.

The lawyer may speak with the person directly, ask questions about their wishes and consider whether the instructions appear consistent and voluntary.

If there are concerns, the lawyer may ask for medical evidence before preparing or witnessing the will.

This can feel like an obstacle, but it may help protect the will from later challenge.

Why Timing Matters

Making or updating a will is usually easier while capacity is clear.

If dementia progresses and capacity becomes uncertain, the process may become harder.

A lawyer may need more evidence.

Family members may disagree.

The will may be more likely to be challenged later.

This does not mean people should rush important decisions.

It means estate planning should not be delayed once capacity concerns are beginning to appear.

Can A Will Be Challenged If The Person Had Dementia?

Yes, a will may be challenged if someone believes the person lacked capacity when it was made.

A diagnosis of dementia does not automatically prove the will is invalid.

However, it may become relevant evidence if there are concerns about understanding, influence or reliability of decision-making.

Late changes to a will may attract closer attention, especially where the changes are unexpected or favour one person strongly.

Pressure And Influence Are Important

Capacity concerns are not only about memory.

Pressure, coercion or influence can also affect whether a will reflects the person’s true wishes.

This may become a concern if someone is isolated, dependent on one family member, being rushed or being encouraged to change a will in a way they do not fully understand.

A valid will should reflect the person’s own decisions, not someone else’s pressure.

Can Someone With Dementia Change Their Will?

Someone with dementia may be able to change their will if they still have testamentary capacity at the time of the change.

The same basic question applies.

Do they understand what they are changing?

Do they understand who may be affected?

Can they explain their reasoning?

Are they making the decision freely?

If the change is significant or unexpected, extra care may be needed.

What If Capacity Is Unclear?

If capacity is unclear, it is usually better not to treat the will as a simple paperwork task.

Uncertainty can create future legal problems.

A lawyer may recommend medical assessment, specialist input or careful documentation of the person’s instructions.

This helps reduce the risk of the will being challenged later.

What You May Really Be Trying To Decide

If you are asking whether someone with dementia can make a will, you may not only be asking about legal rules.

You may be trying to work out whether there is still time to record a person’s wishes before uncertainty grows.

You may be wondering whether:

Mum can still make a valid will
Dad can still change his will
a lawyer will agree to proceed
medical evidence is needed
siblings could challenge the will later

The practical question is this:

Is the person’s decision-making still reliable enough for the will to reflect their true wishes?

How Families Can Approach This Carefully

Families should avoid two common mistakes.

The first mistake is assuming dementia automatically prevents a person from making a will.

That may remove decision-making rights too early.

The second mistake is rushing a will through when understanding, consistency or independence is already uncertain.

That may create legal risk later.

A careful approach is to seek legal advice early, avoid pressure, document concerns and consider medical evidence where capacity is unclear.

Sources

Disclaimer

This article provides general information only. It is not legal, medical or financial advice.

Dementia symptoms, medication guidance, medical advice, aged care services and government policies may change over time and individual circumstances can vary.

Always seek advice from qualified healthcare professionals and refer to official Australian Government, My Aged Care and Dementia Australia resources for current information.

Summary

Someone with dementia may be able to make a will if they still have testamentary capacity.

The diagnosis alone does not decide the issue.

The person must understand what a will does, what they own, who may have a claim and how their decisions may affect others.

If capacity is unclear, early legal advice and appropriate medical evidence may help protect the person’s wishes and reduce future disputes.