You are in a de facto relationship in NSW if you and your partner live together on a genuine domestic basis and are not married to each other or related by family. Section 4AA of the Family Law Act 1975 sets that test. Two years of living together is the usual gateway to a property claim, though it is not the only one, and it is not part of the definition.

Section 4AA decides whether the relationship existed at all. Section 90SB decides whether a court can make property orders about it. Those two get run together constantly. Someone will call having worked out they moved in during March and separated 22 months later, wanting to know which side of the line that puts them on, when the start date is usually the part in dispute anyway. One party dates it from the day the lease started, the other from six or eight months before that. The material that settles it is mundane. Health fund records, the lease, the next of kin field on a hospital admission form, whether the bank had a second cardholder. We ask for that in the first meeting.

Key takeaways

• A de facto relationship in NSW is defined by section 4AA of the Family Law Act 1975, not by a fixed period of time.
• Two years is one of four gateways to a property claim. Children, registration, and substantial contributions are the other three.
• Never having lived under one roof does not rule you out.
• You have two years from separation to bring a de facto property settlement claim.

What is a de facto relationship in NSW?

Two people who are not married to each other and not related by family, living together on a genuine domestic basis. Gender is irrelevant to the test. So is your marital status, which surprises people: you can be in a de facto relationship in NSW while still legally married to somebody else.

The de facto relationship definition then sets out what a court weighs:

• how long the relationship lasted
• the nature and extent of any common residence
• whether a sexual relationship existed
• financial dependence or interdependence, and any financial support between you
• ownership, use and acquisition of property
• the degree of mutual commitment to a shared life
• registration under a state or territory law
• the care and support of children
• how the relationship was regarded publicly

Subsection (4) lets the court attach whatever weight it thinks fit. No box has to be ticked, which is why “am I in a de facto relationship” so rarely gets a clean yes or no over the phone.

How long is a de facto relationship in Australia?

Two years is the answer everyone has heard, and it causes more confusion than any other de facto relationship requirement. That period sits in section 90SB, which governs whether the Federal Circuit and Family Court of Australia has power to make property orders. It is one of four gateways:

• the relationship lasted at least two years in total, including separate periods added together
• there is a child of the relationship
• one party made substantial contributions and would suffer serious injustice without an order
• the relationship was registered under a prescribed state or territory law

Searches like “de facto relationship Australia 6 months” come from the same instinct as the countdown, a belief that a switch flips on a date. Six months with a child clears the hurdle that four years of casual cohabitation might not. Meanwhile, the man at month twenty-three assumes he is safe. He may not be, if two earlier periods count towards the total.

Can you be in a de facto relationship if you never lived together?

Yes, in some circumstances. This is the assumption I most often have to unpick, and people state it with real confidence.

Section 4AA asks about “the nature and extent of their common residence,” which invites a question of degree. Courts have found de facto relationships where the parties kept separate homes, particularly where finances were entangled, or the relationship was public. Separate addresses weaken a case. They do not end it.

So, is a boyfriend a de facto relationship? Not by default, and not after a set number of nights. A partner who keeps his own lease, his own accounts and no shared commitments sits a long way from the description.

How to prove a de facto relationship

The evidence that persuades a court is the same material people assemble for partner visa applications, and it is more mundane than most expect:

• message and call histories showing a continuous relationship
• statutory declarations from friends, family and neighbours
• joint accounts, shared bills, joint loans or a shared lease
• flight and accommodation bookings in both names
• dated photographs, including with each other’s families
• superannuation, insurance or next of kin nominations naming your partner

That list works in both directions. If you are the party saying there was no de facto relationship, the gaps in the paper trail are your case.

Can you register a de facto relationship in NSW?

You can, under the Relationships Register Act 2010 (NSW), through the NSW Registry of Births, Deaths and Marriages. Very few people know this exists, and fewer know what it does.

Registration ends the argument about whether you qualify. It satisfies the section 90SB(d) gateway with no minimum period attached, and it removes the twelve-month cohabitation requirement for a partner visa, which is how most couples find out about it.

Before you register a de facto relationship in NSW, understand that it works in reverse too. If your reason for avoiding marriage is to keep the two financial positions separate, a certificate defeats that.

What are your de facto relationship property rights when it ends?

The same framework that applies to married couples. De facto relationship property rights sit under section 90SM of the Family Law Act, the mirror of section 79 for marriages, and the court identifies the pool, assesses contributions, considers current and future circumstances, then asks whether the result is just and equitable.

That framework was restructured by the Family Law Amendment Act 2024, with the property provisions commencing on 10 June 2025. The effect of family violence on a party’s contributions now sits expressly on the list, alongside wastage and the housing needs of children. Anything predating mid 2025 describes an older structure.

Superannuation can be split. Parenting arrangements run on a separate track under Part VII, unaffected by whether the relationship met the de facto threshold.

Is a de facto entitled to half?

No. The fear of an automatic fifty per cent is the most common thing people bring to a first appointment, and it has no basis in the legislation.

A three-year relationship with no children, both partners in full-time work, rent split and accounts kept separate, tends not to produce much of a fight about percentages. There is not a great deal in the pool that either party built with the other. Superannuation in a relationship that short has usually not diverged far, so each keeps their own, and the real argument narrows to a car, a joint savings account, and who paid for the furniture. Passing the two-year mark does not change that arithmetic. It only allows a claim to be brought.

Where that reassurance runs out is the part worth understanding.

Joint income servicing a pre-relationship asset changes the picture. If both salaries went into the mortgage on an investment property you bought before you met, “I owned it before you” stops being the end of the discussion, because contributions to the preservation and improvement of an asset count, regardless of who holds the title.

Non-financial contributions do real work even without children involved. A partner who relocates interstate for the other’s job, carries the household through a fly-in/fly-out roster, takes a career setback for it, then wears the cost of moving home has a genuine argument for an adjustment in her favour. De facto relationship break-up entitlements above half happen in relationships with no children at all.

Time blends everything. The percentages people report from their own matters (a 68/32 after seventeen years, an estimate around 65/35 for four years) are anecdotes rather than precedents.

One correction, because it is repeated online with confidence. The pool is not today’s value minus its value at the date you moved in. The whole pool is assessable, and pre-relationship assets are weighted within the contributions analysis.

What is the de facto property settlement time limit?

Two years from the date the relationship ended, under section 44(5). After that, you need the court’s leave to apply out of time, and leave is not a formality.

Separation in a de facto relationship rarely comes with a document, so the end date is often contested by a party trying to keep a claim alive.

Then there is the person who says his ex would never take him to court. He may well be right. You cannot build a position on it, because that choice belongs to the other party for a full two years.

Protecting assets in a de facto relationship

A binding financial agreement is the mechanism, made under sections 90UB, 90UC or 90UD depending on whether you are entering the relationship, in it, or ending it. Section 90UJ sets the formal requirements, including independent legal advice for each party.

Australia does not have American-style prenuptial agreements, whatever the films suggest. A binding financial agreement de facto couples sign can be set aside under section 90UM for non-disclosure, fraud or unconscionable conduct. A decades-old document saying one party takes everything will not survive contact with a court.

Trusts deserve their own warning. A trust is often described online as protecting assets in a de facto relationship. Courts look through them, treat trust property as a financial resource, or find the assets to be property of the relationship where one party controls the trust in substance.

Does a de facto have a claim on an estate?

Yes, and this catches families at the worst possible time. Under the Succession Act 2006 (NSW), a surviving de facto partner is treated as a spouse where their partner dies without a will, provided the relationship ran for at least two years or produced a child, which can mean they take the whole estate ahead of adult children.

A de facto claim on an estate can also be brought as a family provision claim under section 57. Estate planning after separation is where most people discover their arrangements no longer say what they assume.

What is the difference between a de facto relationship and marriage?

Legally, less than most assume. The property, superannuation and maintenance regimes are close to identical, and the parenting provisions are identical. A married couple never has to prove the relationship existed, while a de facto couple may have to litigate that question before anyone reaches the property argument.

If you are unsure whether your relationship meets the section 4AA test, or you have separated and want to know where you stand before anything is agreed, that is usually answered in one conversation. We will tell you which gateway applies, what your limitation date is, and what a realistic range looks like on your facts. Book a confidential consultation with our Sydney team.