Falsa Demonstratio Non Nocet: When a Wrong Description in a Will Does Not Void the Gift
A false description in a will — a wrong address, a misspelt name, a wrong number — does not necessarily invalidate the gift. If the subject can be identified by the correct part, the court rejects the false part and gives effect to the true.
How the Maxim Works
False part rejected
Where the description is partly true and partly false, the false part is treated as surplusage — it is set aside. The gift stands on the true part.
Subject must be identifiable
The maxim only saves the gift if the subject (the person or property) can be clearly identified by the remaining true description. Total misdescription fails.
One possible subject
The principle works best where only one person or property fits the correct part of the description. Two equally plausible candidates creates a latent ambiguity — resolved by AJA 1982 s21.
Distinct from rectification
Rectification under s20 AJA 1982 corrects clerical errors or failures to give effect to instructions. Falsa demonstratio is a construction tool that works within the will's own words.
Frequently Asked Questions
What does falsa demonstratio non nocet mean in will interpretation?
Falsa demonstratio non nocet — literally 'a false demonstration does not harm' — is a Latin maxim of will construction. It means that an inaccurate description of the subject of a gift in a will does not automatically cause the gift to fail, provided the subject of the gift can still be identified with sufficient certainty by reference to the true part of the description or from other facts known to the court. The principle is applied where a will contains two descriptions of the subject of a gift — one correct and one incorrect. The court identifies what can be treated as the true, operative part and rejects the false, non-operative part (the 'falsa demonstratio'). The classic formulation is that where the description is partly true and partly false, and the object can be identified by the true part, the false part may be rejected and the gift upheld.
Can you give a practical example of falsa demonstratio in a will?
A classic example: a will leaves property to 'my nephew John Smith of 14 High Street, Exeter'. The testator had only one nephew named John Smith — who lived at 14 High Street, Bristol, not Exeter. The name John Smith is correct; the address is false. Applying falsa demonstratio, the court can reject the false address, identify the nephew by his correct name, and give effect to the gift. A property example: 'I give my property known as Rosewood House, 22 Oak Lane, to my daughter'. The property is actually at 24 Oak Lane. The name 'Rosewood House' is correct; the number 22 is false. If only one property called Rosewood House belongs to the testator, the court can reject the false number and give the correct house to the daughter. The principle does not apply where the description is so fundamentally wrong that no part of it can be treated as reliable.
When does a wrong description in a will cause the gift to fail?
The falsa demonstratio principle only saves a gift where the correct description points clearly to one identifiable subject. It fails and the gift is void where: (1) the description is a total misdescription — every part of it is incorrect and there is nothing to identify the object; (2) the description matches two or more possible subjects with equal accuracy — the court cannot choose between them (though in this case the court may admit extrinsic evidence under s21 Administration of Justice Act 1982 to resolve the latent ambiguity); (3) the wrong description was inserted deliberately — an entirely different gift was intended. The courts are more willing to apply the maxim to correct obvious slips (wrong number, wrong middle name, wrong street) than to rewrite substantive parts of a gift.
How does falsa demonstratio relate to s21 Administration of Justice Act 1982?
Section 21 Administration of Justice Act 1982 permits the admission of extrinsic evidence (including direct evidence of the testator's intention) to clarify a will that is meaningless, ambiguous on its face, or latently ambiguous in the light of surrounding circumstances. Falsa demonstratio and s21 overlap but are distinct: falsa demonstratio is a rule of construction that operates by rejecting a false part of the description and giving effect to the true part — it does not require extrinsic evidence, only that the will itself contains sufficient information to identify the gift when the false part is removed. Section 21 is used where the will is ambiguous even after applying ordinary construction rules — the court then looks beyond the will for evidence of what the testator intended. Both mechanisms are tools for saving a gift that would otherwise fail due to a drafting error or ambiguity.
Does falsa demonstratio apply to mistakes in a beneficiary's name?
Yes — falsa demonstratio frequently applies to misdescriptions of beneficiaries. If the will leaves a gift to 'my niece Elizabeth Robinson' but the testator's only niece is in fact Elizabeth Richardson (a one-letter difference), and there is no Elizabeth Robinson in the family, the court can reject the wrong surname as a falsa demonstratio, identify the correct person from the true part of the description (the niece, named Elizabeth), and uphold the gift. The maxim is applied more readily where: the testator had only one person who could fit the correct part of the description; the error is clearly a clerical or spelling mistake; and there is no real ambiguity about who was intended. If the testator had two nieces — one named Elizabeth and one named Emily — the description creates a different problem (latent ambiguity) that requires different tools.
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