A will is meant to make life easier for the people you leave behind. But when its validity is questioned, an estate can be delayed by disputes, court proceedings and avoidable costs. Understanding what makes a will invalid under NSW law can help you prepare a document that reflects your intentions and stands up when it matters.
A will is not automatically invalid simply because someone is unhappy with it, thinks it is unfair, or expected to inherit more. The real question is whether the document was validly made, represented the will-maker’s genuine wishes and had not been revoked. In New South Wales, the starting point is the Succession Act 2006 (NSW).
What Makes a Will Invalid in NSW?
A will may be invalid if it was not properly signed and witnessed, the will-maker lacked testamentary capacity, or they did not know and approve its contents. It may also fail where there is proven undue influence, fraud or forgery, or where the will was revoked before death.
These issues are fact-specific. A small error does not always defeat a will, and the Supreme Court of NSW can sometimes admit an informal will where there is sufficient evidence that the deceased intended the document to operate as their will. That discretion is useful, but it is not something a family should have to rely on.
The will was not signed and witnessed correctly
For a standard will to meet the formal requirements in section 6 of the Succession Act, it must be in writing and signed by the will-maker, or by another person at their direction and in their presence. The will-maker must intend their signature to give effect to the will.
At least two witnesses must be present at the same time when the will-maker signs or acknowledges their signature. Each witness must then attest and sign the will in the will-maker’s presence. A witness does not need to read the will or know what it says, but the signing process must be handled properly.
Common problems include a witness signing later when the will-maker is not present, only one witness being used, or a person signing on behalf of the will-maker without clear direction. These mistakes can put the whole document at risk.
A beneficiary should generally not act as a witness. In NSW, that does not necessarily invalidate the entire will, but a gift to an attesting witness or that witness’s spouse may be void under section 10 unless an exception applies. Using two independent adult witnesses is the safer course.
The will-maker did not have testamentary capacity
A person must have testamentary capacity when making their will. In plain English, they must understand that they are making a will, have a general understanding of the assets they are dealing with, recognise the people who may reasonably have a claim on their estate, and be able to make a rational decision about who should benefit.
Age, illness, dementia, mental health conditions and medication do not automatically mean a person lacks capacity. A person with early dementia, for example, may still have capacity to make a will, particularly during a clear period. Equally, a person may appear alert but be unable to understand the practical effect of the document they are signing.
Capacity disputes often arise where a will was made shortly before death, after a serious diagnosis, or where it substantially changes earlier estate plans. Medical records, the observations of the solicitor and witnesses, and evidence about the will-maker’s instructions can all become relevant.
When there is any concern about capacity, obtaining a contemporaneous medical assessment and having a solicitor take detailed instructions directly from the will-maker can provide valuable protection. It also helps ensure that family members are not directing the process behind the scenes.
The will-maker did not know and approve the contents
Signing a will is not enough if the will-maker did not understand and approve what was in it. This issue can arise if a person has limited English, poor eyesight, literacy difficulties, hearing impairment, frailty, or relies heavily on another person to explain documents.
It can also arise in suspicious circumstances, such as where the main beneficiary arranged the appointment, gave the instructions, was present for discussions, or received an unexpected benefit. Suspicion alone does not invalidate a will. However, it may require stronger evidence that the will-maker understood the document and made it freely.
A careful solicitor will usually speak with the will-maker alone, explain the effect of key clauses in clear language, record their reasons for significant decisions and arrange an interpreter where needed. These practical steps can be decisive if the will is later challenged.
The will was made under undue influence
Undue influence means more than family pressure, disappointment or persuasion. Adult children may express views about a parent’s estate, and a will-maker may choose to follow that advice. The legal concern is coercion: pressure so serious that the will no longer expresses the will-maker’s own wishes.
Examples might include isolating an elderly person from family, threatening to withdraw care unless the will is changed, or controlling access to legal advice and financial information. Proving undue influence can be difficult because it often happens privately. Evidence may include messages, medical notes, witness accounts and unusual changes in behaviour or estate planning.
The risk is particularly high where a person is dependent on a carer, new partner or relative for daily support. Independent legal advice is not merely a formality in these circumstances. It gives the will-maker a genuine opportunity to give instructions without pressure.
The will is forged or was obtained by fraud
A forged signature, altered document or fake witness signature can invalidate a will. So can fraud, such as deliberately lying to the will-maker about a family member in order to secure a larger gift.
Allegations of fraud are serious and need evidence. Handwriting evidence, communications, document history and the circumstances of execution may all be examined. If a document appears to have been altered after signing, the court may need to determine whether the changes were authorised and whether they affect the will’s operation.
A Valid Will Can Still Be Revoked
A properly executed will is not necessarily the last word. It may be revoked by a later will, by a written revocation executed with the same formalities, or by the will-maker intentionally destroying it with the intention of revoking it.
Marriage generally revokes an existing will in NSW, although there are exceptions, including where the will was made in contemplation of that particular marriage. Divorce does not invalidate the whole will, but it can revoke gifts and appointments in favour of a former spouse, subject to exceptions. Separation alone does not revoke a will.
These rules regularly create unintended outcomes. A person may believe an old will still protects their children after marriage or separation, when the legal effect is very different. Updating estate planning after a relationship change is a practical safeguard, not an administrative task to postpone.
Informal Wills and Digital Documents
A handwritten note, unsent email, draft will or document stored on a mobile may not satisfy the usual signing requirements. That does not mean it will always be ignored. Under section 8 of the Succession Act, the Supreme Court may dispense with formal requirements if satisfied that the deceased intended the document to operate as their will, alteration or revocation of their will.
Court applications about informal wills can be complex, expensive and emotionally draining. The court may need evidence from family members, lawyers, device records and handwriting experts. A clear, professionally prepared will is far more certain than asking loved ones to prove your intentions after you have died.
Practical Steps to Reduce the Risk of a Challenge
Use a current will that clearly identifies you, appoints a suitable executor and deals with your major assets. Sign it correctly with two independent witnesses, and keep the original in a safe place known to your executor.
Review your will after marriage, divorce, separation, buying or selling significant property, starting a business, having children, or experiencing a major change in health or family circumstances. If you intend to leave someone out, or make an unequal distribution between children, obtain advice about both will validity and potential family provision claims. A valid will can still be challenged by an eligible person seeking provision from the estate.
For blended families, vulnerable beneficiaries, business owners and anyone concerned about capacity or pressure from others, tailored advice is particularly worthwhile. GKE Lawyers can help you prepare a will with clear instructions, proper execution and practical records that reduce uncertainty for those you leave behind.
The best time to address a questionable will is while the will-maker can explain their wishes clearly. A short conversation now can spare your family from having to reconstruct them in court later.
