You are here: >> Home >> Articles-BHS Legal >> mistakes in wills

Signing the wrong will by mistake

Finding a mistake or error in the will of the deceased can cause extra difficulties in sorting it out.  Many couples wish to leave their estates to each other when they die.  And then to their children if they have them or if not to the same people.  In addition couples usually nominate the same people to act as their executors and trustees.  Typically to each other and then to one or more of their children as alternatives. 

Putting these intentions into writing in their individual will documents therefore contain identical terms.  They are both look the same except for their names.  Each will reciprocates the contents of the other.  Lawyers commonly refer to these wills as “mirror wills” or reciprocal wills.

Spouses signing each other’s will by mistake

With two wills being the same extra care is needed  during the signing and witnessing formalities so that each will-maker signs the document prepared for them.  Unfortunately there have been instances where spouses have inadvertently signed the will of the other, and the mistake not discovered until after death.

The mistakenly signed will causes a problem when preparing an application for probate of the deceased’s will from the Court.

Applying for probate

When applying for probate, it is a requirement that the original, valid will of the deceased, and signed by them, be produced to the Court together with the probate application.  The difficulty is that the will the deceased signed, was not the one they intended to be their will, the document was not prepared for them, and so does not correctly record their testamentary intentions.

mistakenly wrong will, signing a will, mirror wills, reciprocal wills, mistake, error, will-makingFortunately amendments to the various  wills and succession legislation in the states and territories have provided certain discretionary powers to courts in particular circumstances.

Prior to these amendments strict application of succession law would have meant an intestacy.  Parliaments have made amendments to probate law to give courts discretionary powers so after consideration of the circumstances, they may give legal effect to a will-maker’s intention.


“Mirror” wills

In NSW and South Australian cases where mirror wills prepared for spouses were signed and properly witnessed but by mistake one signed the will of the other, the Courts have been able to use these discretionary powers to find a remedy and avoid an intestacy.  

In doing so Courts have said that there are two potential approaches under the legislation by which they may deal with the problem, although in effect both lead to the same practical outcome.1 The underlying legislative purpose was to give legal effect to the intention of a testator.1

Power of courts to rectify a will where there is a mistake

One way is for the Court to admit to probate the will document the deceased signed by mistake, even though its contents were those contemplated by someone else, (their spouse).

Power to rectify a will

Adopting the rectification power given by the legislation, the Court may rectify a will in certain circumstances if it is satisfied that the will as expressed does not carry out the testator’s intentions.  This is because either a clerical mistake was made or because it does not follow the will-maker’s instructions.  See section 27 of the Succession Act 2006 (NSW) below.

Power to dispense with formal requirements 

The other way is to admit to probate as an informal will, the document which was prepared for the deceased, and which they should have signed, but didn’t, it being signed by their spouse.  Even though this document, being the deceased’s actual will lacks the deceased’s signature and so does not meet the formal legal requirements for signing a will, the Court has power to waive these formalities using the dispensing power given by the legislation. 

To do this the Court must be satisfied that the deceased intended the document to operate as their last will.  In Probate law, the testamentary intention of the deceased is paramount. Courts are concerned about a will-maker’s testamentary intentions, and as expressed in the document they intend to operate as their will.  See section 8 of the Succession Act 2006 (NSW) for example below.

Extra expense and delay from the mistake

Resolving the problem of a mistakenly signed will comes with extra expense and some delay.  This is because an additional application needs to be made to the Probate Court for orders and declarations.  The details will depend upon the specific circumstances in each case but will involve obtaining evidence and preparing court documents.

The Court has very wide powers and may call upon and have regard to any evidence of its choosing in order to discern the testator’s intentions during the process of making their will.   This is a technical area and legal advice and assistance should be sought from solicitors who provide services in this area: follow links to find practitioners here.

The law in New South Wales

When may the Court dispense with the requirements for execution, alteration or revocation of wills? – section 8 of the Succession Act 2006 (NSW) gives the Court discretionary power to dispense with the formalities for executing a will in some circumstances.

Section 27 of the Succession Act 2006 (NSW) provides for when the Court may rectify a will under specific circumstances.  The Court must be satisfied that the will does not carry out the testator’s intentions because:

(a) a clerical error was made, or
(b) the will does not give effect to the testator’s instructions.

An application to rectify a will must be made within 12 months after the date of death.  However the Court may extend this if it considers it necessary and if the estate hasn’t been fully distributed.

The law in South Australia

The validity of a will is set out under section 12 of the Wills Act 1936 (SA).
This section gives the Court a discretion to admit to probate a will even though it has not been executed with the required formalities if it is satisfied that the deceased intended the document to be their will.

Section 25AA of the Wills Act 1936 (SA) gives the Court a discretionary power to rectify a will in particular circumstances.  This rule empowers the Court to give proper expression to a deceased’s intentions if the Court is satisfied that the will doesn’t accurately reflect those intentions.  The time limit on applying to the Court for a rectification order is 6 months after a grant of probate or letters of administration was issued.


Re Estate Johnson, Dec [2014] NSWSC 512
Estate of Daly [2012] NSWSC 555
In the Estate of Hennekam (Dec) [2009] 104 SASC 188


B Stead
BHS Legal

12 May 2016, revised July 2023.

Important notice: This article is intended for general interest and information only. It contains general information and is not specific to anyone’s personal circumstances. It is not legal advice nor should it be used as such. Always consult a legal practitioner for specialist legal advice specific to your needs and circumstances and rely upon that. While every effort is made to ensure accuracy at the time of writing applicable laws may change.

Liability limited by a scheme approved under Professional Standards Legislation.

Copyright © 2023 BHS Legal, publisher of Content is protected by copyright. Please refer to the Terms of Use.


Scroll to Top