Can Someone With Dementia Change Their Will?

Families often ask this question when a person with dementia wants to update an existing will.

Can someone with dementia change their will?

The answer depends on whether the person still has testamentary capacity at the time the change is made.

Dementia does not automatically prevent a will change, but the reasons for the change need to be understood, consistent and genuinely the person’s own.

Short Answer

Yes, someone with dementia may be able to change their will if they still have testamentary capacity when the change is made.

This means they need to understand what a will does, what they own, who may expect to benefit and how the change may affect those people.

The key issue is not the diagnosis alone.

The key issue is whether the person’s decision-making is reliable enough for the will change to reflect their true wishes.

Key Takeaway: A person with dementia may still change their will if they have capacity at the time. Sudden, unexplained or pressured changes may create higher risk of dispute later.

Dementia Does Not Automatically Stop A Will Change

A diagnosis of dementia does not automatically mean a person can no longer change their will.

Capacity depends on the person’s understanding at the time the change is made.

Someone in the early stages of dementia may still clearly understand their assets, family relationships and the effect of changing their will.

However, as dementia progresses, will changes may become more difficult to support if understanding, memory or decision reliability becomes uncertain.

What The Person Needs To Understand

To change a will, the person should generally understand that they are changing a legal document that controls what happens to their estate after death.

They should also broadly understand what they own, who may reasonably expect to benefit and how the proposed change affects those people.

They do not need perfect memory.

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

Decision Reliability Matters

Changing a will is often more sensitive than making one for the first time.

The change may remove someone, add someone, shift money, alter property arrangements or create disagreement between family members.

This is where decision reliability becomes important.

The real question is not only whether the person can say what they want.

The stronger question is:

Are the reasons for the change still coherent, consistent and genuinely their own?

If the person can explain the change clearly and consistently, that may support capacity.

If the reason changes repeatedly, does not make sense, or appears influenced by someone else, the risk increases.

Why Late Will Changes Can Raise Concern

Late changes to a will may attract closer attention, especially when dementia has already been diagnosed.

This does not mean the change is automatically invalid.

It means the circumstances may need to be handled carefully.

Concern may increase if:

the change is sudden or unexpected
one beneficiary receives a much larger share
someone is removed without clear explanation
a carer or new person is added
one family member arranged the appointment
the person appears confused about family relationships
the person seems pressured or dependent on one person

These signs do not automatically prove anything is wrong.

They may mean extra care, legal advice or medical evidence is needed.

Can A Lawyer Refuse To Change The Will?

Yes.

A lawyer may refuse to prepare or witness a will change if they are not satisfied the person has capacity.

The lawyer may want to speak with the person alone, ask detailed questions or request medical evidence.

This is not necessarily a rejection of the person’s wishes.

It may be a protective step to reduce the risk of the will being challenged later.

Medical Evidence May Be Important

If dementia has been diagnosed, medical evidence may help support the will change.

This may involve a GP, specialist or other health professional depending on the circumstances.

The evidence should relate to the person’s ability to understand the will change at the time it is made.

General statements about dementia may not be enough.

The issue is the person’s capacity for this specific decision.

Pressure And Undue Influence

Will changes can become risky when pressure or influence is involved.

This may happen when a person is dependent on one family member, isolated from others or encouraged to make changes quickly.

A person with dementia may still have capacity but be more vulnerable to pressure.

That is why the decision should be clearly their own.

The person should have the chance to speak privately with their lawyer and explain the change without someone else leading the conversation.

Can Family Members Stop The Change?

Family members usually cannot stop a capable person from changing their will simply because they disagree with the decision.

However, family members can raise concerns if they believe capacity, pressure or influence may be an issue.

The focus should remain on evidence rather than family conflict.

Does the person understand the change?

Can they explain their reasons?

Are they making the decision freely?

Is the decision stable over time?

What If The Change Is Unfair?

A will change may feel unfair to some family members.

Unfair does not automatically mean invalid.

A person with capacity can make decisions others dislike.

The key question is whether they understood the decision and made it freely.

However, unexpected or major changes may increase the chance of future dispute, especially if dementia was already affecting decision-making.

What You May Really Be Trying To Decide

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

You may be trying to work out whether a late change is safe, valid or likely to cause problems later.

You may be wondering whether:

Mum still understands the change she wants to make
Dad is being influenced by one person
a sibling can challenge the new will later
a lawyer will require medical evidence
the current will should be reviewed before capacity becomes less clear

The practical question is this:

Does the change reflect reliable, consistent and independent decision-making?

How Families Can Approach This Carefully

Families should avoid two common mistakes.

The first mistake is assuming dementia automatically prevents a will change.

That may take away rights too early.

The second mistake is rushing a will change through when capacity, pressure or reasoning is already uncertain.

That may create serious problems later.

A careful approach is to seek legal advice early, avoid pressure, allow the person to speak privately and consider medical evidence if 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 change their will if they still have testamentary capacity at the time of the change.

The diagnosis alone does not decide the issue.

The key question is whether the person understands the change, can explain their reasons and is making the decision freely.

Where capacity, pressure or influence is uncertain, early legal advice and appropriate medical evidence may help reduce future disputes.