Written By Audrey Diliberto, Partner, Bell Lawyers
Updated September 2026 · 7 min read
Stepfamilies function on relationships that the law of intestacy doesn’t perceive. For instance, if a step-parent passes on without leaving a will, a stepchild he or she raised from infancy has no legal entitlement to inherit anything. The same applies to a de facto partner in some places, if they don’t fulfil specific legal requirements. It’s not a matter of choosing who will inherit the house for these families, as that will be the house of the deceased’s biological relatives. Rather, it’s about selecting the relationships that the law will respect.
Why default rules fail blended families
More than half of adults die without a valid will, a figure regularly cited by public trustee offices and legal bodies. For a nuclear family, intestacy might produce a rough approximation of what the deceased wanted – spouse first, then biological children. For a blended family, it produces chaos.
Intestacy formulas are built around a single marriage and a single set of children. They weren’t written with second marriages, stepchildren, or half-siblings in mind. If a father dies without a will, his estate might go entirely to his current spouse, who has no legal obligation to pass anything to his children from a previous relationship. Those children could end up with nothing, despite the father’s clear intention that they’d be provided for eventually. Stepchildren who were never legally adopted are especially exposed. Emotionally, they may be full members of the family. Legally, in the eyes of intestacy statutes, they’re often strangers.
This isn’t a hypothetical for a small slice of the population. Blended families are now a mainstream family structure, yet estate law hasn’t caught up. Anyone who has remarried, has stepchildren, or has children from more than one relationship needs to treat this as a solvable problem rather than an inevitability – but solving it starts with the will itself, and that’s where a lot of blended family plans fail before they even begin.
The remarriage trap
One small but important detail that takes many people by surprise: a remarriage can invalidate a will automatically, if it was made before the wedding occurred. Under section 12 of the Succession Act 2006 (NSW), marriage revokes a prior will unless that will was made in contemplation of that specific marriage. So, for example, someone who made out a will when they were younger and named their kids as beneficiaries, then remarries and never gets around to changing the old will, could very well be dying intestate without realising it. All that careful planning gets wiped out by a legal technicality nobody warned them about.
This makes a huge difference in the context of second and third marriages. Often, the spouse that contributed to a decade of opening bottlecaps and squishing spiders will assume that their husband or wife’s existing will is fine, because “nothing has changed” in the sense of what they want the money to do – they still want Junior to develop a work ethic and put the grandkids through college. But the very act of remarrying can throw a spike strip under that carefully laid track. The rule is that any bona fide estate plan for a blended family needs to start with a brand new will, in the nice binder, fresh from the lawyer’s envelope; not some recycled printout of an old dream of how things would be.
Superannuation and death benefits sit outside your will
A well-crafted will can take care of many things, but not all. Superannuation and most life insurance benefits are not automatically part of the deceased person’s estate. They are typically managed separately, via a beneficiary nomination or a binding death benefit nomination that is lodged with the fund.
This is the trap that blended families constantly fall into. Someone writes a will that meticulously divides assets between their new spouse and kids from their first marriage, but they never think to update the beneficiary nomination of their super fund. It still lists an ex, or it has lapsed and defaults to “estate,” or it lists just one child when there are three. The super fund trustee pays according to the nomination on their desk, which can blow up all the carefully worded intentions in the will.
For blended families, super is often one of the largest assets at stake, especially for those who die before retirement when it will include a lot of life insurance. Those nominations have to be checked and updated at the same time as the will, not as an afterthought. A binding nomination that is specific, current, and renewed on schedule is the only way to make sure super actually goes where it’s meant to — under regulation 6.17A of the Superannuation Industry (Supervision) Regulations 1994 (Cth), a standard binding nomination lapses three years after it’s signed unless confirmed or renewed.
Testamentary trusts give you control after you’re gone
Many conflicts within a blended family can be traced back to a single structural issue: how do you adequately provide for a surviving spouse without entirely disinheriting your own children (or vice versa)? Counting on a second spouse to make those gifts on their deathbed means hoping they’ll come through on a promise they never made; likewise, hoping that your children will share their eventual inheritance with a long-established stepparent could mean being disappointed. Not due to malice, but because they need it themselves – or because a second, younger spouse and associated children in their turn may feel more entitled to the bounty of the first spouse’s labor.
Testamentary trusts solve this more elegantly than a straight bequest. Instead of gifting assets outright, the will establishes a trust that holds and manages them according to rules the deceased sets in advance. A surviving spouse might receive income from the trust, or a right to live in the family home, while the capital is preserved and eventually passed to the biological children. The trust can also protect assets from a beneficiary’s later divorce, from creditors, or simply from being spent too quickly by someone unprepared to manage a lump sum.
This structure requires more upfront legal work than a simple will, but it directly addresses the central tension in blended family planning: providing for the person you’re with now, while protecting the people who came before them.
Family provision claims are a real risk, not a scare tactic
Even if a will is in place, it can still be contested. Under section 57 of the Succession Act 2006 (NSW), certain individuals — including a stepchild who was, at any time, wholly or partly dependent on the deceased and a member of their household — are “eligible persons” who can bring a family provision claim if they believe adequate provision hasn’t been made for them. This is a harsh but important reality of blended family planning: having good intentions and some paperwork in place will not necessarily solve the problem.
The safest response is not to try to work out who might be successful in a claim and hope they don’t contest it. The safest approach is to make adequate provision for anyone who could credibly bring a claim and outline in a clear and legally binding document the reasons why they have not been provided for. A well-drafted statement of reasons will not automatically result in a claim being thrown out, but it will put the estate in a much stronger position. Pretending the issue doesn’t exist and hoping everything will be fine is a risk most people don’t want to take.
Naming guardians is about more than just who raises the kids
Deciding who will care for your minor children if you die is a serious and delicate process that raises difficult, often uncomfortable, questions.
The best choice for guardian rarely boils down to just who’s closest or who’s oldest. Siblings may not be best to stay together, nor might they be best split apart. Grandparents may be loving but not in a position, health-wise, to take on the responsibility. Close friends may share your values, but if they are significantly older, they might not be physically up to the job when you fade away naturally. Choosing between a warm, nurturing family with a different faith, or neighbours with whom you have much in common is an unnecessary rift waiting to happen.
If you have a blended family and minor children, the selection argument can escalate horrifyingly fast. A biological parent will most likely assume their ex will never get custody after they die, but a court will usually award parental responsibility to the surviving biological parent regardless of their relationship history or any agreements in place with the deceased ex. A biological parent might also wrongly assume that their new spouse will automatically be given control of the child if they die — that isn’t guaranteed either.
A will should name a guardian clearly, but it should also address how that guardian will handle the child’s inheritance, education costs, and living arrangements. Money left directly to a minor typically needs to be held in trust until they reach a set age anyway, so the will needs to specify who controls that trust and under what conditions funds can be released.
Planning for incapacity, not just death
When we talk about estate planning, everyone thinks of last wills and testaments, but medical and financial powers of attorney are equally important. These documents dictate who gets to make decisions when you can’t. If they’re not in place, your family might spend a fortune in court determining who’s in charge. It’s up to you to decide if you’d rather have your stepchildren battle their step-parent in court or mediate this decision over the dining room table.
This is a document set people neglect because it feels less urgent than a will. It’s arguably more urgent, since incapacity can happen without warning and last for years, during which unresolved authority can freeze decision-making at the worst possible time.
Binding financial agreements as a companion tool
Estate documents don’t operate in isolation from family law more broadly. Binding financial agreements — the prenuptial and cohabitation agreements provided for under Part VIIIA of the Family Law Act 1975 (Cth), used to define what stays separate property and what happens on separation — work alongside a will rather than replacing it. An agreement that protects pre-existing assets from a future property claim gives an estate plan a firmer foundation, because it removes ambiguity about what was always meant to be ring-fenced for biological children versus what’s shared with a current partner. These agreements should be reviewed at the same time as wills and trusts, not treated as a one-off exercise completed before a wedding and never revisited.
Choosing an executor who won’t inflame the conflict
The person appointed to administer an estate has real power: this person can gather assets, pay debts, determine intent in cases of vague bequest, and arbitrate disputes that arise between heirs and beneficiaries.
In a blended family scenario where there’s already underlying tension between the surviving spouse and the deceased’s biological children, making one of the parties the sole executor only throws petrol on an existing flame — in these situations, an independent executor or professional trustee frequently makes more sense.
This person has no emotional skin in the game regarding one side of the family prevailing over the other, and no innate emotional predisposition to try to maintain the peace. An independent executor is also likely to be well-versed in how these sad family schisms work and may be able to anticipate the areas of conflict.
Getting the drafting and the review right
Getting the structure right in the beginning is more important in blended families than almost anywhere else in estate law, since the number of moving parts – trusts, nominations, guardianship, financial agreements, provision claims – is seriously greater than in a regular household. Working with a lawyer who can structure these documents around your family’s exact dynamics, rather than a generic template that assumes a much simpler family tree than the one you truly have, is what keeps a plan realistic rather than aspirational. Reviewing the complete set of documents every few years, or directly after any major life event, is what keeps the plan matching the family it’s meant to protect.
None of this can be accomplished as a one-off. Family structures change – new weddings, new kids, divorces, deaths, relocations – and every one of those events can quietly invalidate the assumptions embedded in an old estate plan. A will developed for a two-kid family ten years ago may not contain anything useful about a stepchild who entered the family five years after, or a grandkid born after it was finalised.
A look at how these cases play out
A pattern like this comes up often in blended family estate matters: a father remarries, updates his will to divide his estate between his new wife and his two adult children from his first marriage, and assumes the job is done. What he doesn’t revisit is his superannuation nomination, still made out to his first wife from over a decade earlier and now lapsed.
When he dies, the will is followed for the assets it actually covers — but the super, often the single largest asset in the estate, falls to the fund trustee’s discretion because the nomination had lapsed years earlier. The trustee’s default process doesn’t automatically follow the will’s intentions, and the family is left negotiating — or litigating — over an asset the will was never able to reach in the first place. The fix, when caught in time, is straightforward: a current, correctly witnessed binding nomination reviewed alongside the will. The problem is that most people don’t think to check it until it’s already too late.
This example reflects a pattern seen across blended family estate matters generally; details have been generalised and don’t describe a specific, identifiable client. Every case turns on its own facts.
Conclusion
Blended families don’t get the luxury of the law’s default settings. That’s not a defect in the family – it’s a gap in documents most people never think to fill until it’s too late to fix. Reviewing wills, nominations, and powers of attorney together, and revisiting them after every major life event, is what keeps a plan matching the family it’s meant to protect. A family lawyer experienced in wills and estates can help structure these documents around a family’s actual circumstances, rather than a template built for a simpler family tree.
Authorities & Sources
- Succession Act 2006 (NSW) s 12 — Effect of marriage on a will.
- Succession Act 2006 (NSW) s 57 — Eligible persons for a family provision order.
- Superannuation Industry (Supervision) Regulations 1994 (Cth) reg 6.17A — Binding death benefit nominations.
- Family Law Act 1975 (Cth) s 90B — Financial agreements before marriage.
Legal information can change, and how a specific estate plan should be structured depends on individual family circumstances, assets, and the relevant state or territory law. This article is for general informational purposes and is not a substitute for legal advice about a specific situation.
