A parent dies, the will is read, and almost everything goes to the one person who was around at the end. A new partner. A carer. The adult child who moved back in to help. The rest of the family knew nothing about the change, and something about it feels wrong.
If that is where you are, here is the short answer. Yes, a will can be set aside for undue influence. But only if you can prove actual coercion, real pressure that overbore the will-maker’s free choice, not persuasion, not a difficult relationship, and not simply the fact that someone was close enough to have influence. That is a high bar, and I would rather be honest about it up front than sell you a comfortable version.
Below I break down what undue influence in a will actually means, who can challenge one, the evidence that counts, and how to act before it is too late. No jargon, just a straight answer. As wills and estates lawyers, me and my team see this more often than you would think.
What undue influence in a will actually means
Undue influence in a will, what lawyers call testamentary undue influence, is not about someone being persuasive. It is about coercion: pressure so strong it overpowers the will-maker’s free will, so the final document reflects someone else’s wishes rather than their own. The will-maker (the testator) signs it, but the choices inside it are no longer really theirs.
The line the courts draw here is old, and it is strict. A relative can argue their case, plead, even wear a person down. A carer can make themselves indispensable. None of that is undue influence on its own. Since Wingrove v Wingrove (1885), the courts have treated pressure as crossing the line only when it amounts to coercion that overbears the will-maker’s free choice. Persuasion, however unwelcome, is not enough.
All of this sits under the rules on will validity in the Succession Act 2006 (NSW), the legislation that governs what makes a will valid in this state.
Why “presumed” undue influence does not apply to wills
This is where a lot of people get caught out, and it is the single most important thing on this page.
You may have read that when someone is in a position of trust, a carer, an adviser, an adult child running the finances, the law assumes they applied undue influence, and it falls to them to prove they did not. That is true for contracts and for gifts made during a person’s lifetime. In those situations, equity can presume undue influence from the relationship itself and shift the burden onto the person who benefited.
For a will, it does not work that way. There is no presumption. The person alleging undue influence has to prove actual coercion, and that burden stays on them from start to finish. This is confirmed by the Australian Law Reform Commission, which sets out plainly that the presumption available for lifetime dealings does not carry over to wills.
I know that feels backwards, especially when the circumstances look suspicious. But knowing it now changes how you approach this. You cannot simply point at the relationship and expect the court to fill in the rest. You have to build the case.
Signs a will may have been made under undue influence
Certain circumstances make a court look harder at a will. Lawyers call them suspicious circumstances. On their own they do not prove undue influence, but together they can be enough for a court to want a closer look:
- The will-maker was isolated, frail, or dependent on one person.
- A new will appeared late in life and suddenly favoured that one person.
- The person who benefited arranged the lawyer, sat in on the meeting, or was there when the will was signed.
- The new will was kept secret from the rest of the family.
- The will departed sharply from what the will-maker had always said they would do.
None of these is proof. A frail parent is allowed to change their mind, and being close to someone at the end of their life is not wrongdoing. But when several of these line up, they are worth taking seriously, and they are the starting point for the evidence a court will want to see.
Who can challenge a will, and the evidence that counts
Not just anyone can challenge a will. You need a genuine interest in the estate, usually because you were a beneficiary under an earlier will, or because you would inherit under the intestacy rules if this will were set aside. If that is you, contesting a will on the ground of undue influence is open to you.
Because the burden is on you, the evidence has to do the heavy lifting. What actually counts:
- The solicitor’s file notes from when the will was made: who booked the appointment, who was in the room, and whose instructions were being followed.
- Medical records showing the will-maker’s health, and whether they were vulnerable to pressure at the time.
- Accounts from people who saw the relationship up close: family, friends, carers, neighbours.
- The circumstances around the will itself: how it came to be made, how quickly, and how far it moved from the will-maker’s known intentions.
Documents created at the time carry far more weight than recollections formed after the death. That is why the solicitor’s file is often the most important thing in the whole matter.
Even with all of that, though, these claims are hard to win. It is worth understanding why before you decide what to do.
How hard is undue influence to prove?
I will be honest with you, because it matters more than a reassuring line would. Successful undue influence claims against a will are rare. The reason is built into the law. You have to prove actual coercion, the courts set the bar high, and the one person who could explain what really happened, the will-maker, is no longer here to say.
They do succeed. In one case, a court found that part of an elderly, vulnerable will-maker’s later will had been procured by undue influence and refused probate of the affected gifts, while admitting the rest (Nicholson v Knaggs [2009] VSC 64, a Victorian decision). But cases like that turn on strong, specific evidence of pressure, not on suspicion alone.
None of that means you should walk away. It means you should go in with clear eyes: get advice early, and gather the evidence while it still exists.
What happens if undue influence is proven
If a court accepts that a will was made under undue influence, it does not rewrite it. It has two options. It can refuse to admit the whole will to probate, or it can sever the affected part and admit the rest.
If the whole will falls away, the estate does not simply pass to whoever challenged it. It is distributed under the will-maker’s previous valid will, if there is one. If there is no earlier will, it passes under the NSW intestacy rules, which set a fixed order of who inherits. That may or may not be the outcome you were hoping for, which is another reason to get advice before contesting a will rather than after.
Time limits and acting early
Timing is where these cases are often won or lost. A challenge to a will’s validity is best raised before probate is granted. The tool for that is a caveat, which asks the court not to grant probate until the concerns are looked at. Once probate is granted and the estate is distributed, unwinding it is far harder.
This runs on a different clock from a family provision claim, and people mix the two up. A family provision claim does not say the will is invalid. It accepts the will and asks the court for a larger share for an eligible person. In NSW, that application has to be made within 12 months of the date of death (Succession Act 2006 (NSW), s 58(2)).
Either way, the earlier you act, the more control you have. Once the estate is gone, so are most of your options.
Undue influence, testamentary capacity, and family provision are not the same thing
People arrive at this on the wrong ground all the time, so it is worth drawing the lines clearly:
- Undue influence is about coercion. Someone overbore the will-maker’s free choice.
- Testamentary capacity is about understanding. It asks whether the will-maker had the mental capacity to know what they were doing when they made the will. A will can be entirely free of pressure and still fail because the will-maker did not understand it.
- A family provision claim does not challenge the will at all. It accepts the will as valid and asks the court for a larger or fairer share for an eligible person.
If you are not sure which one fits your situation, that is normal, and it is exactly the kind of thing a short conversation can sort out.
Worried a will was made under pressure?
If you think a parent or someone close to you signed a will under pressure, the timing above is the part that matters most. Once the estate is distributed, your options narrow. You do not need to have it all worked out first.
Book a free discovery call with me and my team. We will listen to what happened, tell you honestly whether there is something worth pursuing, and explain your options and the next step. If there is nothing in it, we will tell you that too, and you will not have lost anything.
Call 1300 614 732 or send us a message to speak with our wills and estates lawyers.
Frequently Asked Questions
What is undue influence in a will?
Undue influence in a will is coercion strong enough to overpower the will-maker’s free choice, so the will reflects someone else’s wishes rather than their own. It is more than persuasion or a close relationship. The pressure has to override the will-maker’s own decision-making.
Can a will be challenged for undue influence in Australia?
Yes. A will can be set aside if you can prove actual coercion overbore the will-maker’s free choice. Successful claims are rare, because the burden of proof sits on the person challenging the will and the courts set a high bar. Strong, specific evidence is essential.
How do you prove undue influence in a will?
To prove undue influence in a will you need evidence of actual coercion, not just suspicion. That usually means the solicitor’s file notes, medical records showing vulnerability, and accounts from people who saw the relationship and the pressure firsthand. The burden stays on the person challenging.
Why is undue influence in a will so hard to prove?
Because you have to show actual coercion, the burden stays on you throughout, and the will-maker is no longer alive to explain what happened. Courts set a high bar, so these claims succeed only on strong, specific evidence of pressure rather than suspicion.
What is the difference between undue influence and testamentary capacity?
Undue influence is about coercion, whether someone overbore the will-maker’s free choice. Testamentary capacity is about understanding, whether the will-maker had the mental capacity to know what they were doing. A will can be free of pressure and still fail for lack of capacity.
Is there a time limit to challenge a will for undue influence?
A validity challenge is best raised before probate is granted, by lodging a caveat, and it becomes much harder afterwards. A family provision claim is different: in NSW it must be made within 12 months of the date of death under the Succession Act 2006 (NSW).
