How much does it cost to contest a will?

Legal costs for contesting a will vary depending on case complexity, whether matters settle or proceed to trial, the amount in dispute, and your lawyer’s fee structure. Our will dispute lawyers work on a No Win No Fee basis for family provision claims, meaning you pay reduced or no legal fees if your claim is unsuccessful. If your claim succeeds, costs may be paid from the estate or by the losing party depending on circumstances and court orders. We offer free initial consultations, allowing you to understand likely costs before committing to proceed. Learn more: Who pays legal costs when contesting a will?

Can a stepchild contest a will?

Yes, stepchildren can contest a will in Australia if they are eligible for a family provision claim. This generally includes stepchildren who were financially dependent on the deceased, lived in the deceased’s household, or were owed a moral duty of support. The success of such claims depends on factors including: The length and nature of the relationship Whether the deceased stood in the position of a parent The stepchild’s financial needs Provisions made for biological children compared to stepchildren

Can a brother contest a will if his sister is the executor?

Yes, you can contest a will even if the executor is your sibling. However, this may create additional complexity. The executor has a duty to defend the will against challenges, which may create tension when they’re also a family member and potentially a beneficiary. If there’s a conflict of interest or the executor acts improperly, the court can appoint an independent administrator. Your claim focuses on whether the will provides adequately for you—not on your sister’s conduct as executor—though any misconduct by the executor could be addressed separately.

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Can a sibling contest a will? A guide for family members

Written by: Richele Nelsen
5 January 2026
Read time: 11m

The death of a parent or family member often brings not only grief but also complex questions about inheritance and estate distribution. When a sibling receives significantly more from an estate—or you’ve been excluded entirely—you may wonder whether you can challenge the will.

This December 2025 guide explains whether siblings can contest a will and under what circumstances you can bring a family provision claim. It also looks at how common it is for siblings to dispute inheritance, helping you understand your rights and options during this difficult time.

Can siblings contest a will in Australia?

Yes, siblings can contest a will in Australia, but the ability to do so depends on your relationship with the deceased and your specific circumstances. Australian succession law allows challenges to a will on different grounds, such as lack of testamentary capacity or family provision claims, and a sibling’s rights depend on the type of claim they are making.

Eligibility for family provision claims

The most common way for siblings to challenge a will is through a family provision claim (sometimes called a family maintenance claim in certain states). However, being a sibling does not automatically make you eligible.

To qualify, you typically need to show that you were:

Financially dependent, either fully or partially, on the deceased at the time of their death
A member of the deceased’s household
Someone to whom the deceased owed a moral obligation to provide

Simply being a biological sibling does not automatically give you the right to contest a parent’s will if you were financially independent and not living with or supported by them. The law recognises that self-sufficient adult children or siblings may not have a claim on the estate, even if they feel emotionally entitled to an inheritance.

State variations in sibling rights

Eligibility criteria for contesting a will vary by state and territory:

New South Wales

Under the Succession Act 2006, immediate family members such as spouses, de facto partners, children, and former spouses are automatically eligible to contest a will in NSW.

Siblings are not expressly listed but may be eligible if they lived with the deceased and were wholly or partly dependent on them, or if a close personal relationship existed at the time of death.

Victoria

In Victoria, the Administration and Probate Act 1958 allows a broader interpretation of eligible persons when contesting a will.

Claimants must show the deceased had a moral obligation to provide for them. This can include members of the household, stepchildren, grandchildren and others who were financially dependent or in need.

Adult siblings may be eligible in limited circumstances where financial need and moral obligation can be demonstrated.

Queensland

Under the Succession Act 1981, only the deceased’s spouse, children (including adopted and stepchildren), and dependants have an unconditional right to claim in Queensland.

Siblings are not automatically eligible and must show they were financially supported by the deceased at the time of death.

While the laws differ by state, the principle is the same. You need to show financial dependence or another connection that created a reasonable expectation of support, not just a family relationship.

Being someone's sibling doesn't automatically give you standing to contest their will. You must fit within your state's definition of an eligible person, which typically requires proving dependency, household membership, or that the deceased owed you a moral obligation to provide.

Key takeaway

Common reasons siblings contest wills

When siblings do contest wills, certain patterns and circumstances are common. Understanding these common scenarios can help you determine if you can contest a will and whether your situation might warrant legal action.

1. Unequal distribution between siblings

One of the most common reasons for challenging a will is when a parent leaves significantly more to one sibling than the others. Parents have the right to distribute their estates unequally, but their decisions can be challenged if they do not provide adequately for siblings with real financial needs.

When deciding these cases, courts look at factors such as each sibling’s:

Financial situation
Health and care needs
Contributions to the deceased’s wellbeing or estate

They will also assess the reasons for the unequal distribution and the size of the estate compared with competing claims. Courts do not require parents to treat all children equally. However, they do expect that children with genuine need are provided for appropriately.

2. Complete exclusion from the will

Being entirely excluded from a parent’s will raises questions about whether the deceased properly considered their obligations. This is a key issue when considering contesting a parent’s will.

While parents can disinherit children, courts scrutinise such decisions, particularly when:

The excluded sibling has significant financial need
Other siblings received substantial inheritances
No clear explanation exists for the exclusion
The relationship breakdown occurred due to circumstances beyond the excluded sibling’s control

Estrangement doesn’t automatically justify exclusion, particularly if the relationship difficulties stemmed from factors like:

Mental health issues
The deceased’s conduct
Family manipulation by other siblings

Learn more: What grounds do you have to contest a will?

3. Disputes over family provision

Sometimes siblings aren’t excluded entirely but receive provisions they consider inadequate compared to their needs or to what other siblings received.

These disputes often occur when:

One sibling has health issues or disabilities requiring ongoing support
One sibling sacrificed career opportunities to care for the deceased
One sibling has dependent children, while others don’t
The deceased made lifetime gifts to some siblings but not others

Courts assess whether the provision made in the will is adequate given each person’s circumstances, not whether it’s equal or “fair” in some abstract sense.

4. Challenges based on undue influence

Siblings sometimes contest wills, alleging that another sibling or third party improperly influenced the deceased. These claims don’t require proving you’re an eligible person for family provision. Instead, they challenge the validity of the will itself.

Undue influence claims occur when one sibling may have manipulated a vulnerable parent, isolated the deceased from other family members, pressured the parent into changing their will, or exploited a position of trust or dependence.

Proving undue influence requires showing that the deceased’s will didn’t reflect their genuine wishes but instead resulted from another’s coercion or manipulation.

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What if a sibling won't cooperate with inheritance?

Sometimes the issue isn’t contesting the will itself but dealing with a sibling who is acting as executor and not properly administering the estate. This creates different legal challenges requiring different remedies.

Issue	Legal Approach
1. When executors fail their duties	If your sibling is the executor and refuses to distribute the estate, withholds information about estate assets, mismanages or misappropriates estate funds, or unreasonably delays administration, you can apply to the court to compel them to fulfil their duties or have them removed as executor. Executors owe fiduciary duties to beneficiaries. They can be held personally liable for breaching these duties, including being required to compensate the estate for any losses caused by their misconduct.
2. Beneficiary disputes between siblings	Even when the will is clear, siblings may: Dispute its interpretation Disagree about the value of assets they’re meant to share Contest which assets form part of the estate Disagree about the timing of distribution These disputes don’t necessarily involve contesting the will but may require mediation or court intervention to resolve disagreements about implementation.

Issue

Legal Approach

1. When executors fail their duties

If your sibling is the executor and refuses to distribute the estate, withholds information about estate assets, mismanages or misappropriates estate funds, or unreasonably delays administration, you can apply to the court to compel them to fulfil their duties or have them removed as executor.

Executors owe fiduciary duties to beneficiaries. They can be held personally liable for breaching these duties, including being required to compensate the estate for any losses caused by their misconduct.

2. Beneficiary disputes between siblings

Even when the will is clear, siblings may:

Dispute its interpretation
Disagree about the value of assets they’re meant to share
Contest which assets form part of the estate
Disagree about the timing of distribution

These disputes don’t necessarily involve contesting the will but may require mediation or court intervention to resolve disagreements about implementation.

If your sibling is both the executor and a major beneficiary, there can be a conflict of interest. Courts recognise this and may scrutinise their conduct more closely or appoint an independent administrator if concerns about bias or self-dealing come up.

Important note

How common is it for siblings to fight over inheritance?

Inheritance disputes over estates and wills are relatively common in Australia, and a significant portion involve family provision claims between children of the deceased. Empirical research shows that about half of contested estates in Australia are fought under family provision laws, with most claims brought by immediate family members, such as children, and intra-sibling contests were identified as the predominant form of conflict in a study of disputed wills.

Factors that increase sibling conflicts

Certain circumstances make sibling inheritance disputes more likely:

1. Lack of communication	When parents don’t explain their estate planning decisions, siblings left with unequal provisions may feel betrayed or confused, leading to challenges.
2. Family dynamics	Long-standing sibling rivalries, perceptions of favouritism, or unresolved childhood issues often resurface during estate administration.
3. Blended families	Step-siblings and half-siblings may have different relationships with the deceased and competing claims on estates.
4. Caregiving imbalances	When one sibling provided significant care for aging parents while others remained distant, resentment about equal distribution can lead to disputes.
5. Financial desperation	Siblings facing financial hardship may contest wills they might otherwise have accepted, driven by genuine need rather than greed.

How successful are people at contesting a will?

Success rates for will contests vary significantly based on the grounds for challenge and the strength of evidence. Family provision claims tend to have higher success rates, while challenges to the validity of a will, such as undue influence, are generally more difficult to establish.

In Australia, empirical research shows that family provision claims—where an eligible person argues they were not adequately provided for under a will—have a relatively high success rate. Around 74% resulted in a change to distribution in contested cases examined in a national study of court judgments.

Undue influence claims are harder to prove because they require evidence that the will-maker’s free will was overridden at the time the will was made, which is often difficult to establish after death. Lack of capacity claims face similar challenges, as the law presumes capacity and courts generally require clear contemporaneous medical or other objective evidence to rebut that presumption.

Understanding success and compensation

Success doesn’t necessarily mean obtaining everything you sought. It often means negotiating an increased (though still potentially modest) provision from the estate.

For example, one of our clients successfully contested his late mother’s intestate Queensland estate and received $120,000, while the other parties’ claims were unsuccessful. This illustrates that even when a claim succeeds, the outcome depends on the strength of the case, the evidence available, and the court’s assessment.

Similarly, in another case, a Cessnock woman was awarded over $350,000 after being left out of her father’s will, with the court providing for her accommodation, education, and living needs. These examples highlight that family provision claims can result in significant adjustments to an estate, but outcomes depend on the claimant’s circumstances and the court’s assessment of what is “adequate provision.”

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What can you do if you've been left out of a will?

If you’re a sibling who has been excluded from or inadequately provided for in a will, understanding your options and time constraints is crucial.

1. Assess your eligibility

First, determine whether you qualify as an eligible person under your state’s succession legislation.

This typically requires showing that you:

Were dependent on the deceased financially
Were a member of their household
Had a relationship where the deceased owed you a moral obligation to provide

If you can’t meet these criteria, your options for bringing a family provision claim are limited, though you might still challenge the will’s validity on grounds like undue influence or lack of capacity if evidence supports such claims.

Learn more: Five examples of wills that have been contested

2. Gather supporting evidence

If you decide to pursue a claim, you’ll need to demonstrate:

Your financial circumstances and needs
The nature of your relationship with the deceased
Any contributions you made to their wellbeing or estate
Reasons why the deceased should have provided for you
The size and nature of the estate
Other beneficiaries’ circumstances and the adequacy of their provisions

Documentation such as financial records, medical reports if you have health issues, correspondence with the deceased, and evidence of caregiving or support you provided strengthens your case.

3. Understand time limits

Time limits for contesting a will are strict and vary by state:

New South Wales: 12 months from the grant of probate or administration.
Victoria: Six months from the grant of probate or administration.
Queensland: Nine months from the grant of probate or administration.
South Australia: Six months from the grant of probate or administration.
Tasmania: Three months from the grant of probate or administration.
Northern Territory: 12 months from the grant of probate or administration.
Western Australia: Six months from the grant of probate or administration.

Missing these deadlines typically bars your claim permanently, though courts have limited discretion to extend time in exceptional circumstances.

4. Seek legal advice early

Contesting a will involves complex legal issues and strict procedural requirements. Consulting experienced will dispute lawyers helps you understand whether you have viable grounds for challenge, what evidence you need, realistic expectations for outcomes, and strategies for resolution.

Our estate dispute lawyers offer initial consultations and many work on a No Win No Fee basis for family provision claims, making legal advice accessible even if you’re facing financial difficulties. We have offices in Brisbane, Melbourne, and Sydney, and specialise in a wide range of claims, from public trustee matters to contested wills.

Next steps with GMP Law

At GMP Law, we offer No Win, No Fee representation, so you won’t pay legal fees unless your claim is successful. If you believe you’ve been affected by medical negligence, acting early can make a real difference.

Here’s how to get started:

Frequently asked questions on can a sibling contest a will

How much does it cost to contest a will?

Legal costs for contesting a will vary depending on case complexity, whether matters settle or proceed to trial, the amount in dispute, and your lawyer’s fee structure.

Our will dispute lawyers work on a No Win No Fee basis for family provision claims, meaning you pay reduced or no legal fees if your claim is unsuccessful. If your claim succeeds, costs may be paid from the estate or by the losing party depending on circumstances and court orders.

We offer free initial consultations, allowing you to understand likely costs before committing to proceed.

Learn more: Who pays legal costs when contesting a will?
Can a stepchild contest a will?
Yes, stepchildren can contest a will in Australia if they are eligible for a family provision claim. This generally includes stepchildren who were financially dependent on the deceased, lived in the deceased’s household, or were owed a moral duty of support.

The success of such claims depends on factors including:
- The length and nature of the relationship
- Whether the deceased stood in the position of a parent
- The stepchild’s financial needs
- Provisions made for biological children compared to stepchildren
Can a brother contest a will if his sister is the executor?

Yes, you can contest a will even if the executor is your sibling. However, this may create additional complexity. The executor has a duty to defend the will against challenges, which may create tension when they’re also a family member and potentially a beneficiary.

If there’s a conflict of interest or the executor acts improperly, the court can appoint an independent administrator. Your claim focuses on whether the will provides adequately for you—not on your sister’s conduct as executor—though any misconduct by the executor could be addressed separately.

About the Author

Richele Nelsen

Partner

Richele Nelsen is a seasoned personal injury lawyer with 14 years' experience. Driven by her law and social science (criminology) background, she fights hard to get injured clients the compensation they deserve. She specialises in Institutional Abuse and Public Liability.

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Can a sibling contest a will? A guide for family members