What is undue influence and can it invalidate a Will?

A Will must represent the free and voluntary wishes of the person signing it. If a Will was obtained through pressure, manipulation, or coercion, it is void. In Queensland, challenging a Will on the grounds of “undue influence” is a powerful but legally demanding option.

What is Testamentary Undue Influence?

In everyday terms, we think of “influence” as persuasion. However, the law does not prohibit family members from persuading or pleading with a relative to leave them a gift.

Under Queensland law, testamentary undue influence requires proof of coercion. It must be shown that the testator’s free will was completely overborne by another person, to the point that the testator signed a document they did not truly want to sign. The classic formulation is that the testator was led to say: “This is not my wish, but I must do it.”

The leading High Court of Australia authority on undue influence and unconscionable conduct in family transactions is Bridgewater v Leahy.¹ This case confirmed that equity will intervene to protect vulnerable parties where there is a position of special disadvantage and another party unconscionably takes advantage of that position to procure a benefit.

The Lifetime vs. Testamentary Distinction

It is critical to distinguish between lifetime transactions (like gifting a house while alive) and testamentary transactions (making a Will):

• Lifetime Gifts (Equitable Undue Influence): If a vulnerable parent transfers an asset to an adult child who cares for them, the law often presumes undue influence existed because of the relationship of trust and dependence. The receiving child must prove the transaction was fair.
• Wills (Testamentary Undue Influence): In a Will dispute, there is no presumption of undue influence. The person challenging the Will has the entire burden of proving that actual coercion took place. This is a very high legal threshold, as the main witness (the testator) is deceased.

The Blank Will Trap: Invalidity and Forgery

A particularly serious form of Will tampering arises when a carer or relative obtains the testator’s signature on a blank Will form or template, promising to “fill in the details later” according to the testator’s verbal instructions.

This is invalid and illegal for multiple reasons under Queensland law:

1. Formal Execution Failure: Under Section 10 of the Succession Act 1981 (Qld),² a Will must be in writing and signed after the contents are complete. A document signed blank is not a valid testamentary instrument.
2. Lack of Knowledge and Approval: The executor must prove the testator knew and approved of the contents of the Will. A person cannot know and approve of a blank page.
3. Criminal Forgery: Completing a blank-signed Will with content that benefits yourself, or changes the deceased’s intentions, is a serious crime. Under Section 488 of the Criminal Code Act 1899 (Qld),³ the forgery of a testamentary instrument (a Will) is a crime carrying a maximum penalty of 14 years imprisonment.

If a carer or relative claims to have a Will that was filled in after the testator signed it, or if you suspect the signatures of the witnesses were obtained separately (e.g., claiming a friend witnessed it in another state), the Will is highly vulnerable to a challenge for formal invalidity and fraud.

Proving Undue Influence in Court

Because direct evidence of coercion is rarely available (pressure usually occurs behind closed doors), the court will look at circumstantial evidence:

• Vulnerability of the Testator: Was the testator physically weak, bedridden, cognitively impaired, or entirely dependent on the person who benefits under the Will?
• Isolation: Did the beneficiary isolate the testator from other family members, friends, or independent professionals?
• Involvement in Preparation: Did the beneficiary arrange the Will, write the draft, or take the testator to a new solicitor?
• Sudden Changes: Does the Will represent a sudden, unexplained departure from a lifetime of previous Wills and statements?

If the court finds that a Will was obtained by undue influence, the Will is declared void. The estate is then distributed under the testator’s last valid Will. If no prior Will exists, the estate is distributed in equal shares to the closest surviving relatives under the rules of intestacy.⁴

Related Topics

• Can I challenge a Will signed by someone with dementia?
• What are the witnessing requirements for a valid Will in Queensland?
• Who can challenge a Will in Queensland?
• Dying without a Will: Queensland Intestacy Rules
• Legal Matters Ep 16: Technology Law & Estate Questions

Professional Guidance

Challenging a Will on the grounds of undue influence requires a meticulous gathering of evidence. The experienced estate litigation solicitors at Bell & Senior Lawyers can assess your situation and advise on your options.

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