Estate Planning for Blended Families

Disclaimer: This guide is for educational purposes only and does not constitute legal advice. Blended family situations are complex and often require professional guidance. We strongly recommend consulting a qualified estate planning solicitor for advice specific to your situation.

Overview

Blended families are increasingly common in Australia. You might have children from a previous relationship, your partner might have children, or you might have children together — or all three.

But here’s the problem: standard estate planning advice assumes a traditional nuclear family. It doesn’t account for:

• Children you love but aren’t legally related to
• A current spouse you want to provide for and children from a previous relationship who also need protection
• Ex-spouses who might still have claims on your estate
• Complex emotional dynamics where one wrong decision can fracture relationships

When you die, your will becomes a legal document in a system that doesn’t automatically recognise the reality of modern families. Stepchildren aren’t “children” in the eyes of the law. Your intentions don’t matter if they’re not properly documented. And without careful planning, the people you’re trying to protect can end up fighting each other.

This guide walks you through the specific challenges blended families face — and how to address them.

Who legally counts as “family” in your will

This is where blended families hit their first surprise.

The legal hierarchy

When Australian law talks about your family, it recognises:

Automatic legal relationship:

• Biological children
• Legally adopted children
• Your spouse or de facto partner
• Your parents and siblings

No automatic legal relationship:

• Stepchildren (unless formally adopted)
• Your partner’s children
• Foster children
• Children you’ve raised but never formally adopted

This creates a critical gap. If you write “I leave my estate to my children,” the law interprets that as your biological and adopted children only. The stepchildren you’ve raised for 15 years don’t count — unless you specifically name them.

Example: The unintended exclusion

Sarah’s situation: Sarah remarried when her biological daughter Emma was 8. Her new husband David had a son, Jake, who was 6. Sarah and David raised both children together for 12 years. Sarah considers Jake her son. She never formally adopted him, but she assumed her will would cover “both my children.”

Sarah’s will says: “I leave my estate equally to my children.”

What happens when Sarah dies: Under Australian law, “my children” means Emma only. Jake receives nothing. David might be devastated. The family could fracture. And Sarah’s actual intentions — to treat both children equally — aren’t followed.

The fix: Name everyone specifically: “I leave my estate equally to my daughter Emma [surname] and my stepson Jake [surname].”

Common mistakes blended families make

Mistake 1: Leaving everything to your spouse

The scenario: You remarry. You leave everything to your new spouse, assuming they’ll look after your children from your first marriage.

What can go wrong:

• Your spouse could remarry and leave everything to their new partner
• Your spouse could change their will and exclude your children entirely
• Your children and spouse might not get along after you’re gone
• Your spouse might outlive you by decades, and your children receive nothing until they’re in their 60s
• If your spouse dies without a will, intestacy rules apply — and your children likely get nothing

Mistake 2: Mirror wills that don’t account for blended families

The scenario: You and your spouse make matching wills: “Everything to my spouse, then to our children.”

What can go wrong: After you die, your spouse can change their will. They could:

• Leave everything to their biological children only
• Remarry and leave it all to their new spouse
• Cut out your children entirely

There’s no legal mechanism forcing your spouse to honour the original agreement.

Mistake 3: Assuming stepchildren are covered by intestacy

If you die without a valid will, intestacy rules apply. These rules give your estate to your closest relatives in a specific order.

Protecting your current spouse AND your biological children

This is the central tension in most blended family estates: you want to provide for your spouse, but you also want to ensure your children from a previous relationship ultimately receive an inheritance.

The competing interests

Your spouse needs:

• Financial security after you die
• Somewhere to live
• Access to income for living expenses
• Control over day-to-day finances

Your children need:

• Assurance they’ll eventually inherit
• Protection against their inheritance being diverted
• Fair treatment compared to any stepchildren

Strategy 1: Life interest (right to reside)

A life interest gives your spouse the right to live in your property for the rest of their life, but they don’t own it. When they die or move out, the property passes to your children.

How it works:

• Your will leaves your house to your children
• But your spouse has the right to live in it until they die or remarry
• Your spouse can’t sell it, mortgage it, or give it to someone else
• When they die, your children inherit

Advantages:

• Your spouse has housing security
• Your children are guaranteed to inherit eventually
• Clear and enforceable

Disadvantages:

• Your spouse can’t downsize or sell (they’re stuck in the house)
• Maintenance costs fall on the children (who don’t live there)
• Can create resentment if the house needs expensive repairs
• Your spouse might feel like a tenant in “their” home

Example: Michael’s life interest will

Michael owns a house worth $800,000. He has two adult children from his first marriage and a current wife, Linda.

His will states:

• Linda has the right to live in the house for life, or until she remarries
• When Linda dies or moves out, the house passes to his children equally
• Linda cannot sell, mortgage, or alter the property without the children’s consent

What happens: When Michael dies, Linda continues living in the house. She’s secure. But 15 years later, Linda develops mobility issues and needs to move into aged care. The house is sold. The children receive the proceeds.

Linda’s security was protected, and the children eventually inherited.

Strategy 2: Testamentary trust

A testamentary trust is a trust created by your will that comes into effect when you die. It’s one of the most flexible tools for blended families.

How it works:

• Your will creates a trust when you die
• Your assets go into the trust (not directly to beneficiaries)
• You appoint trustees to manage the trust according to your instructions
• The trust provides income to your spouse
• When your spouse dies, the capital goes to your children

Advantages:

• Your spouse receives financial support
• Your children are protected as ultimate beneficiaries
• Trustees must follow your instructions
• Flexible — can account for changing circumstances
• Tax advantages in some situations
• Protection from creditors and divorce

Disadvantages:

• More expensive to set up
• Requires ongoing administration
• Trustees have discretion, which can cause conflict
• May take longer to distribute the estate

Example: Rebecca’s testamentary trust

Rebecca has $600,000 in assets. She has three children from her first marriage and a current husband, Paul, who has limited superannuation.

Her will creates a testamentary trust:

• Paul receives all income generated by the trust (dividends, rent, interest)
• Trustees can use capital for Paul’s medical or aged care needs
• When Paul dies, remaining capital is divided equally among her three children
• If Paul remarries, income payments reduce by 50%

What happens: When Rebecca dies, the $600,000 goes into a trust. Paul receives approximately $24,000/year in income (4% return). He’s financially comfortable. Ten years later, Paul needs aged care. The trustees release $80,000 from the trust capital to cover his bond. When Paul dies, Rebecca’s children share the remaining $520,000.

Paul was supported. Rebecca’s children inherited. The trust worked as intended.

Binding financial agreements and wills working together

A binding financial agreement (BFA) is like a prenuptial agreement. It’s a legal contract between you and your partner that sets out what happens to your assets if you separate or one of you dies.

When a BFA makes sense

• You have significant assets you want to protect for your children
• Your partner has their own assets and children to provide for
• You want to limit potential claims against your estate
• You’re entering a second or third marriage with complex financial arrangements

Example: James and Sophie’s binding financial agreement

James is 58, with two adult children and a house worth $1.2 million. Sophie is 54, with one daughter and her own apartment.

Before marrying, they sign a BFA stating:

• James’s house remains his separate property and will go to his children
• Sophie’s apartment remains her separate property and will go to her daughter
• Neither will make a claim against the other’s estate
• They’ll share living expenses but keep assets separate

When James dies, Sophie cannot claim against his estate under family provision laws. James’s children inherit the house as intended. Sophie retains her own apartment for her daughter.

The BFA gave both families certainty.

Ex-spouses and former relationships

Your ex-spouse may still have claims on your estate even after divorce — not through your will, but through other mechanisms.

Update your superannuation nominations

Critical: Superannuation doesn’t automatically follow your will. If your super nomination still names your ex-spouse, they could receive your entire super balance when you die — even if you’ve been divorced for 20 years.

What to do:

• Log into every super fund you have
• Check your current death benefit nominations
• Update them to reflect your current wishes
• Use binding nominations (non-lapsing if available)
• Review every 3 years or after major life events

Life insurance beneficiaries

Similar issue: life insurance policies often have named beneficiaries. If your ex-spouse is still listed, they’ll receive the payout.

Action required:

• Contact every insurer
• Update beneficiary details
• Consider making your estate the beneficiary (so it follows your will)

Child support obligations

If you have ongoing child support obligations, these continue after death. Your estate may be liable for unpaid child support or future obligations.

What happens if you die without a will

Intestacy rules in blended families are particularly harsh.

Typical intestacy distribution (simplified)

If you die without a will in Australia:

If you have a spouse and children:

• Spouse receives a statutory legacy (amount varies by state, typically $100k-$500k) plus household items
• Remainder split between spouse and children (usually 50/50 or 33/66 depending on state)

Who counts as “children”:

• Biological children only
• Adopted children only
• NOT stepchildren

Example: Daniel dies without updating his will

Daniel remarried 10 years ago. He has two biological children from his first marriage (now adults) and raised his wife Karen’s daughter from age 6 to 16.

Daniel’s will is 25 years old and leaves everything to his first wife (now ex-wife). That will is no longer valid because divorce revokes provisions for ex-spouses in most states.

When Daniel dies, he’s effectively intestate. His $800,000 estate is distributed under intestacy rules:

• Karen receives $100,000 plus household items
• Remaining $700,000 split: $350k to Karen, $175k to each of his two biological children

Karen’s daughter receives nothing, despite Daniel raising her for 10 years.

Family provision claims: Who can challenge your will

Even with a well-drafted will, certain people can apply to court claiming they should receive more from your estate.

Who can make a claim

Almost always eligible:

• Your spouse or de facto partner
• Your biological or adopted children (including adult children)
• Former spouses in some circumstances

Sometimes eligible:

• Stepchildren who were dependent on you
• Grandchildren you were maintaining
• People in a close personal relationship with you

When stepchildren can claim

A stepchild can make a family provision claim if they can prove they were:

• Wholly or partly dependent on you at the time of your death
• A member of your household
• Treated by you as a child of the family

Courts will consider:

• How long you supported them
• Whether you acted as a parent
• Their financial needs
• The size of your estate
• Other beneficiaries’ needs

Example: Melissa’s stepson’s claim

Melissa raised her stepson Tom from age 4 to 18. She paid for his education, supported him through university, and treated him as her son. Her will left everything to her biological daughter.

When Melissa died, Tom made a family provision claim. The court found:

• Melissa treated Tom as her child for 14 years
• Tom had a moral claim on her estate
• The estate was large enough to provide for both children

The court ordered Tom receive 30% of the estate, despite not being in the will.

How to minimize family provision claims

• Include everyone with a moral claim in your will (even if the amount is small)
• Explain your decisions in a letter or statement of wishes (not binding, but can influence courts)
• Use a binding financial agreement to limit spousal claims
• Make adequate provision for dependents
• Document your reasoning if you’re excluding someone
• Get professional advice — poorly drafted clauses can backfire

Key strategies for blended family estate planning

Questions to discuss with your partner

Before finalizing your estate plan, work through these questions together:

Real families, real lessons

Related resources

Dictionary Terms:

• Testamentary Trust
• Life Interest
• Family Provision Claim
• Binding Death Benefit Nomination
• Intestacy

Guides:

• How to Choose the Right Executor
• What Your Will Doesn’t Cover
• Choosing the Right Type of Will

Planning Tools:

• Asset Inventory Checklist
• Executor Checklist

Final thoughts

Blended family estate planning isn’t about choosing between your spouse and your children. It’s about finding structures that protect everyone fairly.

The families that get this right tend to have three things in common:

1. They use legal structures, not promises — testamentary trusts, binding nominations, properly drafted wills
2. They communicate openly — adult children and new spouses understand the reasoning
3. They get professional help — these situations are too complex for generic templates

Your family is unique. Your estate plan should be too.

The cost of getting it wrong isn’t measured in legal fees. It’s measured in broken relationships, years of court battles, and the feeling that the person who died couldn’t see past their own death to protect the people they loved most.

Get it right. Your family will thank you.