Living with a partner feels simple until it isn’t. Two people live together as a couple without being married, share a lease, split the bills, maybe raise a child together, and assume that if things end, they can just walk away the way they walked in. That assumption is the problem.
Cohabitation without marriage is legally recognized as a de facto relationship under the Family Law Act 1975 when couples live together on a genuine domestic basis, and that legal status can carry real financial consequences long before either partner has thought about registering anything or signing a single form.
Left unaddressed, this gap between what couples assume and what the law actually says can turn a straightforward breakup into a drawn out dispute over property, superannuation, and financial support, often at the exact moment when neither partner has the energy for it. The good news is that this is entirely avoidable with the right information and the right advice early on.
This article walks through the rise of cohabitation in Australia, why it tends to be more fragile than marriage even among couples with children, and the legal protections available to de facto couples so you know where you stand before a problem shows up.
The Rise of Cohabitation in Australia
Cohabitation is no longer seen as merely a stepping stone to marriage for many couples in Australia. Instead, it has become the norm for a large and growing share of relationships.
According to data cited by the Australian Institute of Family Studies, married couple households made up the majority of Australian households in 1995 but that share has fallen over the following decades, while cohabiting couple households have more than doubled over the same period, with the shift most pronounced among younger Australians.
Separately, industry estimates suggest around 6 per cent of couples in Australia were cohabiting, an increase on previous decades and a trend expected to continue.
Several factors contribute to this shift.
Changing Social Norms
Over the last few decades, societal views on relationships have shifted significantly. Cohabitation, once stigmatised, is now widely accepted as a valid and respectable relationship status. The traditional expectation to marry early and form a family has lessened, with more emphasis placed on individual freedom and relationship choices.
Financial Considerations
Cohabiting often provides financial benefits that allow couples to share living expenses, making it easier for them to test their compatibility before committing to marriage. With rising housing costs and financial instability affecting many young people, cohabitation can be an economically practical solution.
Postponing Marriage
Many Australians are choosing to delay marriage. This delay can be attributed to factors such as the pursuit of career goals, personal development, or the increasing costs of weddings. As a result, cohabitation becomes a more convenient and flexible option for couples who want to live together without the formal commitment of marriage.
Although some couples eventually transition from cohabitation to marriage, a growing number of Australians choose to remain in long-term cohabiting relationships, sometimes raising children together without ever formalising the relationship through marriage.
Cohabitation Is Legally Framed as a De Facto Relationship
This is the part most couples skip past, and it is the part that matters most. Simply living with someone and being in a sexual relationship with them does not, by itself, mean you are already in a de facto relationship. Under the Family Law Act 1975, a person is in a de facto relationship with another person if the two of you are not married to each other, are not related by family, and are living together as a couple on a genuine domestic basis.
There is no minimum period of cohabitation required under family law for a relationship to be recognised as de facto.
Courts assess the overall nature of the relationship, and a de facto relationship can be found to exist even where a couple has lived together for only a few weeks, provided the following factors are sufficiently established:
- The duration of the relationship
- The nature and extent of common residence
- Whether a sexual relationship exists
- The degree of financial dependence or interdependence between the partners
- Ownership, use, and acquisition of property
- The degree of mutual commitment to a shared life
- Whether the relationship is formally registered
- Care and support arrangements for any children
- The reputation and public perception of the relationship, meaning whether family, friends, and the community see you as a couple rather than housemates
Even couples who are not living under the same roof full time are not automatically excluded. A concept sometimes called “de facto by distance” applies where a couple exclusively stays at each other’s homes and otherwise meets the criteria above; even something as simple as one partner receiving mail at the other’s address can be relevant evidence in a dispute.
On the other end of the spectrum, relationships involving paid personal care, such as a live-in carer receiving a wage or government payment, are generally excluded from the definition, as are living arrangements based purely on companionship without evidence of the other factors.
Courts have gone both ways on close calls. In one Family Court matter, a couple who had an on-and-off sexual relationship for 13 years and had two children together, but who had lived in the same house for less than a year, was found not to be in a de facto relationship.
In a more recent case, a couple who had cohabited across multiple addresses for around six years, shared day to day expenses, kept separate bank accounts, and presented publicly as a couple was found to have been in a de facto relationship for approximately four and a half years, despite the respondent arguing the relationship was casual and non-exclusive.
These cases show how fact-specific this area of law is, and why couples in an ambiguous situation should learn about your de facto legal rights from a family lawyer rather than assume either way.
If a dispute over de facto status ends up before a court or a government agency, evidence is typically drawn from Centrelink records, third party sources such as banks, employers, and the ATO, and statements from the couple themselves, family, and friends.
The Fragility of Cohabitation Compared to Marriage
While cohabitation is increasingly popular, research consistently indicates that it tends to be less stable than marriage. Couples who live together without marrying are statistically more likely to separate, even if they have children together.
Several long-term studies have reported that couples who cohabited before marriage tend to report higher rates of relationship breakdown and somewhat lower relationship satisfaction than couples who did not cohabit first, though researchers continue to debate how large this effect really is and how much of it reflects who chooses to cohabit in the first place rather than cohabitation itself.
A few recurring themes come up across this body of research:
Perceived Flexibility
Cohabiting couples often view their relationship as more flexible and less binding than marriage. This perception can make it easier for them to end the relationship without the legal complexities that marriage entails. The absence of formal legal ties may also create a sense of impermanence, leading some couples to exit the relationship more readily.
Lack of Formal Commitment
Marriage is often seen as a formal declaration of commitment, involving both legal and societal expectations. Without this legal and societal bond, cohabiting couples may feel less pressure to work through challenges in their relationship. This lack of formal commitment can contribute to a higher rate of separation.
Fewer Legal Protections, Historically
Before legal reforms were introduced, de facto relationships did not offer the same level of legal protection as marriage. This disparity in rights and protections may have contributed to the fragility of cohabiting relationships. With the introduction of new laws, de facto couples now enjoy many of the same rights as married couples, which can help reduce some of the practical uncertainty associated with cohabitation, even if the emotional dynamics remain different.
Legal Changes: The Family Law Amendment Act 2008
In response to the growing prevalence of de facto relationships, the Australian government introduced the Family Law Amendment Act 2008, which came into effect in 2009. This legislation significantly changed the legal landscape for de facto couples, granting them many of the same rights and responsibilities as married couples in areas such as property division and spousal maintenance. The key legal protections for de facto couples include the following.
Property Division
Under the Family Law Amendment Act, de facto couples who have lived together for at least two years, or who have a child together, are generally entitled to a fair division of property in the event of separation. This applies to assets acquired during the relationship, including real estate, investments, and superannuation.
The Family Court can also make property orders outside the two-year threshold where the relationship is registered, or where one partner made a significant contribution and failing to make an order would result in serious injustice.
The net asset pool considered by the court includes everything acquired before, during, or after separation, regardless of whether it was owned jointly or individually, and this extends to debts as well as assets. When working out a property settlement, the court weighs each partner’s financial and non-financial contributions, such as income, homemaking, and childcare, alongside future needs. Settlement outcomes are not fixed by a formula.
Some people search for a “70/30 divorce settlement” expecting a set ratio, but Australian courts do not work from a default split; every outcome depends on the specific contributions and future needs of the two people involved, which is exactly why tailored advice from an Australia family lawyer matters more than any online calculator.
Property disputes in de facto relationships can sometimes be more complicated than in a marriage simply because there is no marriage certificate to point to, so engaging a family lawyer early is worthwhile. There are three broad ways to sort out property after separation: an informal private agreement, turning that agreement into consent orders filed with the court, or a formal Binding Financial Agreement.
It is crucial to note that a claim for property settlement as a de facto partner must generally be made within two years of the date of separation, and missing that window can mean needing the court’s permission to apply late.
Spousal Maintenance
Just like married couples, de facto couples can claim spousal maintenance if they meet specific criteria. This ensures that one partner is financially supported after separation, particularly if they sacrificed their career or financial independence during the relationship.
The court considers factors including each partner’s age, income, property, and financial resources, their ability to work, and whether the relationship affected their capacity to earn. A former partner is not required to pay maintenance if they are not reasonably able to do so once their own reasonable expenses are accounted for.
Income can come from less conventional sources than a regular payslip, and courts generally look at someone’s real earning capacity rather than just their declared income, which is part of why questions like is OnlyFans illegal sometimes come up in the context of disclosing true financial position during a separation.
Parental Rights
De facto couples who have children together enjoy the same rights and responsibilities regarding their children as married couples. This includes decisions related to child custody, parenting arrangements, and financial support. Courts consider the best interests of the child, regardless of the parents’ marital status.
Parenting time is generally structured around what suits a child’s age and developmental needs, and many separating parents look into typical child custody schedules by age in Australia as a starting point before negotiating their own arrangement, since what works for an infant looks very different from what works for a teenager.
Related questions tend to come up alongside these arrangements too, including whether one parent can enrol a child in a new school without the other parent’s permission, or more specifically, whether a child’s school can be changed without the father’s consent.
Where a relationship has involved family violence, this can also affect both parenting arrangements and any protection orders in place, and partners sometimes later look into the reasons to revoke an intervention order once circumstances genuinely change; this is a decision that should always be made with proper legal advice given the safety issues involved.
Registering a De Facto Relationship
Registering the de facto relationship, generally through your state or territory’s Registry of Births, Deaths and Marriages, makes your cohabitation formally documented. In New South Wales, for example, both parties generally need to be over 18, have at least one party residing in the state, and not already be married, registered with someone else, or related to each other.
Registration can strengthen your position in a dispute, avoid arguments about whether the two-year threshold has been met, and matters like Wills, superannuation nominations, and other planning.
It is worth noting that registration operates differently again for immigration purposes: a partner visa application generally requires at least 12 months of cohabitation or a registered relationship, which is a separate test from the broader, no-minimum-period assessment family law courts apply.
Cohabitation Versus Marriage: Key Differences
Although cohabitation and marriage have significant overlap when it comes to property division, support payments, and children, there are meaningful legal differences between the two.
| Aspect | Marriage | De Facto Relationship |
|---|---|---|
| Formal steps to begin | Requires a marriage licence | No formal or legal steps required to begin cohabiting |
| Exclusivity | Legally exclusive; bigamy is a criminal offence | Multiple de facto relationships are legally possible, though complex to prove, and generally must be exclusive for immigration purposes |
| Ending the relationship | Requires a formal divorce through the court | Ends upon separation; registered relationships require formal revocation |
| Property division eligibility | Available regardless of the length of the marriage or whether there are children | Generally requires at least two years together, a child of the relationship, or a significant contribution |
| Time limit to apply for property orders | 12 months from when the divorce is finalised | 2 years from the date of separation |
| Effect of death without a Will | A surviving spouse usually inherits part of the estate automatically | A surviving de facto partner has similar entitlements to a share of the estate, the right to challenge a Will, and access to compensation and social security entitlements, but this can be harder to establish without documentation |
Considering a Cohabitation Agreement
A cohabitation agreement is a legal document between an unmarried couple that specifies what will happen to various assets in the case of a future separation. It is a type of Binding Financial Agreement regulated under the Family Law Act 1975, and while it is not compulsory for couples living together in Australia, it is legally binding as long as it complies with the requirements of the Act. A cohabitation agreement can cover:
- Separate assets that one partner owns and keeps after a breakup
- Shared assets that both partners own and agree to divide in a set way
- Debt obligations such as co-signed loans that both partners are jointly responsible for
- Maintenance payments that one partner may provide the other if they are experiencing financial hardship
For a Binding Financial Agreement to be valid, both partners need independent legal advice before signing, and the agreement must be signed and dated by both parties.
While a cohabitation agreement is not legally mandatory, having one in place gives both partners a say over what happens if the relationship ends and can meaningfully reduce conflict and legal costs down the track.
The Role of Family Law Solicitors for De Facto Couples
Navigating the legal aspects of living together in a de facto relationship can be challenging, particularly when it comes to property division, spousal maintenance, and child custody. Engaging an experienced family lawyer can help couples understand their legal rights and responsibilities and ensure that any disputes are handled fairly and efficiently.
Family law solicitors provide valuable guidance in drafting Binding Financial Agreements, which can outline how assets will be divided if the relationship ends. They can also assist with negotiating property settlements, applying for spousal maintenance, and ensuring de facto couples receive the financial support they are entitled to after separation.
If a dispute cannot be resolved directly, mediation is often the recommended next step, since it is less formal and less costly than going to court; if mediation does not resolve things, arbitration or a court application through the Federal Circuit and Family Court of Australia may be necessary.
For couples considering cohabitation, or those already in a de facto relationship, seeking legal advice early on can help avoid complications later.
Speaking with a family lawyer at Collective Family Law Group ensures that both partners are well informed and protected throughout the relationship, not just at the point where things go wrong.
Conclusion
As cohabitation continues to rise in Australia, understanding the legal and social implications is essential for couples. The Family Law Amendment Act 2008 has helped bridge the gap between married and cohabiting couples, offering de facto couples similar protections in areas like property division, spousal maintenance, and parenting arrangements.
Even so, it is worth approaching cohabitation with a clear-eyed understanding of its potential fragility compared to marriage, and of the practical steps, like a cohabitation agreement or registering the relationship, that can protect both partners regardless of how the relationship unfolds.
If you are in a cohabiting relationship and want to make sure your rights are protected, it is always a good idea to seek legal advice.
Speak to the team at Collective Family Law Group for personalised guidance on de facto relationships, property division, and spousal maintenance. Our experienced family lawyers, including Hayder Shkara, Caralee Fontenele, and Julie Fotheringham, along with the rest of our family law team, are ready to help you understand exactly where you stand. Book a free initial appointment with any of our experienced family lawyers today.
Related questions tend to come up around the same time, including how to change back to a maiden name after a divorce is finalised, so it can be worth working through the full picture with your lawyer in one conversation rather than piecemeal.
Disclaimer: This article is for informational purposes only and should not be taken as legal advice. For tailored advice specific to your circumstances, please consult with a family lawyer at Collective Family Law Group.
FAQs
Is cohabitation legal in Australia?
Yes. There is no law against two people living together without being married, and same-sex and opposite-sex couples are treated the same way under the Family Law Act 1975. Once a cohabiting couple is living together on a genuine domestic basis, however, the relationship is generally recognised as a de facto relationship, which brings with it certain legal rights and obligations around property, children, and financial support.
What are the rules of cohabitation?
There is no single rulebook, but the law does apply once a relationship meets the definition of de facto. Courts look at factors such as how long you have lived together, whether you are in a sexual relationship, how financially interdependent you are, whether you have children together, whether you have registered the relationship, and how the relationship is viewed by family and friends. There is generally no minimum time requirement under family law, though a de facto couple typically needs two years together, a child of the relationship, or a significant contribution before they can apply for a property settlement.
Can my girlfriend take half my house in Australia?
Not automatically, and not simply because you are living together. Whether a partner is entitled to a share of a property you own depends on whether a de facto relationship exists, how long you have been together, and each person’s financial and non-financial contributions to that property and the relationship as a whole. For a full breakdown of how this is assessed, see our detailed guide on whether a girlfriend can take half your house in Australia.
What are the legal rights of a live-in partner?
A live-in partner who meets the definition of a de facto relationship generally has rights similar to a married spouse, including the right to seek a fair division of property and superannuation, the right to apply for spousal maintenance if they cannot adequately support themselves, and rights relating to any children of the relationship. If a partner dies without a Will, a de facto partner may also be entitled to a share of the estate or be able to challenge the Will, along with access to certain compensation and social security entitlements.
