Binding Financial Agreements In Western Australia: How WA Law Differs

Western Australia is the only state that never referred its general de facto property powers to the Commonwealth.

Married couples in WA make binding financial agreements under Part VIIIA of the Family Law Act 1975 (Cth).

De facto couples in WA make them under Part 5A of the Family Court Act 1997 (WA).

The two sets of rules look alike, but the section numbers, time limits and superannuation rules are not the same.

A template written for the federal regime names the wrong Act for a de facto couple in Perth, and that is not a cosmetic error.

Knowing which law applies to you is the difference between an agreement that holds and one a court can declare is not binding.

Which Law Applies To Your Binding Financial Agreement In Western Australia?

Your relationship status is the starting point.

If you are married or planning to marry, your agreement is made under Part VIIIA of the Family Law Act 1975 (Cth), the same federal law that applies in every other state.

If you are in a de facto relationship, or about to enter one, your agreement is made under Part 5A of the Family Court Act 1997 (WA), which is state law and applies only in Western Australia.

A couple who are living together and also planning to marry may need advice covering both periods, because an agreement made in contemplation of marriage may not deal with a separation that happens before the wedding.

Most of the differences that follow flow from that starting point.

The table below compares the two tracks across the points that matter most when an agreement is drafted.

The most important thing this comparison shows is that a de facto couple in WA does not make their agreement under the federal financial agreement provisions.

References to sections 90B, 90C or 90G in a de facto agreement signed in Perth point to a law that does not govern how that agreement is made.

Superannuation is the one exception, because the splitting mechanism for WA de facto couples sits in the federal Act.

A court asked to enforce it will look at Part 5A of the Family Court Act, not Part VIIIA of the Family Law Act.

The married track is far from a niche concern here, with the Australian Bureau of Statistics recording 13,208 marriages registered in Western Australia in 2025.

Why Does Western Australia Have Its Own De Facto Law?

WA never handed its de facto financial powers to the Commonwealth, so those powers stayed with the state parliament.

Every other state referred that power and the territories are covered without needing to refer anything, which is why de facto couples elsewhere in Australia come under the Family Law Act.

When the federal parliament built its de facto financial regime, Western Australia sat outside it and kept its own scheme under the Family Court Act 1997 (WA).

The result is a national system with one carve-out, and that carve-out is the whole reason WA agreements need to be drafted differently.

Which Court Hears These Matters?

The Family Court of Western Australia hears both, which is part of why the difference gets overlooked.

WA is the only state with its own standalone family court, and that court wears two hats.

When it deals with a married couple it exercises federal jurisdiction under the Family Law Act.

When it deals with a de facto couple it exercises state jurisdiction under the Family Court Act 1997 (WA).

The exception is superannuation splitting for de facto couples, which the court deals with under federal law.

Same building, same judges, and different statutes depending on the issue.

What Section Numbers Apply To A De Facto Agreement In WA?

Sections 205ZN, 205ZO and 205ZP of the Family Court Act 1997 (WA) cover the three points at which a de facto couple can make a financial agreement.

Section 205ZN covers an agreement made before the de facto relationship begins, which is the state equivalent of a prenuptial agreement.

Section 205ZO covers an agreement made during the relationship.

Section 205ZP covers an agreement made after the relationship has ended.

The WA Act labels each of these sections with its federal counterpart, so section 205ZN carries the note “FLA s. 90B” and section 205ZS carries the note “FLA s. 90G”.

Those notes are a useful signal, because they show which federal provision each WA section was modelled on.

They do not make the federal sections apply.

The WA sections also have their own drafting, so what each one requires needs to be checked against the WA Act rather than assumed from the federal equivalent.

An agreement that cites a federal section instead of the WA section is citing a law with no work to do in a WA de facto matter.

You can read the current consolidated version on the WA legislation website.

Do You Need To Have Lived Together For Two Years Before A WA Court Will Divide Property?

Usually yes, and there are two exceptions.

The Family Court of Western Australia states that a party must show they lived in a de facto relationship with the other party for at least two years before the court can make a property order.

The first exception applies where there is a child of the relationship under 18 and failure to make orders would result in serious injustice to the party caring for that child.

The second applies where the party applying has made substantial financial, non-financial or homemaker contributions and failing to make orders would result in serious injustice.

This threshold is about when a court can make property orders, not about when a couple can make an agreement.

Section 205ZN lets a couple make a financial agreement before the de facto relationship even begins, so there is no waiting period before you can sign.

A couple six months into living together can put an agreement in place, and it is built to operate whenever the relationship ends, including years later.

The document should be drafted to work across the whole life of the relationship rather than the moment it is signed.

What Connection To Western Australia Does A De Facto Property Case Need?

A real link to the state is needed before the Family Court of Western Australia can deal with a de facto property case.

The Family Court of Western Australia sets out two requirements that both have to be met.

One or both partners must have been resident in Western Australia on the day the application was made.

On top of that, either both partners must have lived in Western Australia for at least one third of the de facto relationship, or the applicant must have made substantial contributions in Western Australia.

This is a test for bringing a case in Western Australia, rather than a test for whether a couple can make an agreement.

This is where couples who move around get caught out.

Fly-in fly-out work, interstate transfers and long stretches spent working in another state can all raise questions about where a relationship has been lived, though where someone works is not on its own the answer.

A couple who spent most of their relationship in Queensland and only recently arrived in Perth may not meet the WA connection test.

The sensible course is to work out where the relationship has actually been based before deciding which agreement to draft.

How Long Do You Have To Apply For A Property Settlement In WA?

Married couples have 12 months and de facto couples have two years, measured from different starting points.

For a married couple, section 44(3) of the Family Law Act gives 12 months from the date the divorce order takes effect, not from separation.

For a de facto couple in WA, section 205ZB of the Family Court Act 1997 (WA) gives two years from the date the relationship ended.

Both periods can be extended by leave of the court, and leave is not automatic.

Running out of time is not always the end of the road.

Section 205ZB allows the court to grant leave to apply late if satisfied that hardship would be caused to the de facto partner or a child.

An application can also be made if both partners consent to it, although the court can dismiss proceedings where that consent was obtained by fraud, duress or unconscionable conduct.

There is a further 12 month period that runs from the date a financial agreement between the partners is set aside or found to be invalid.

That last point matters, because it means a failed agreement does not automatically leave a party out of time.

These deadlines bite more often than people expect.

The Australian Bureau of Statistics recorded 49,158 divorces granted in Australia in 2025, with a median of 9.4 years from marriage to separation and 13.4 years from marriage to divorce.

A gap that long between the wedding and the paperwork is exactly why what was agreed at the start needs to be written down clearly.

Can De Facto Couples In WA Split Superannuation In A Binding Financial Agreement?

Yes, and only since 28 September 2022.

Before that date, de facto couples in Western Australia could not make a binding split of a superannuation interest.

The change came through the Family Law Amendment (Western Australia De Facto Superannuation Splitting and Bankruptcy) Act 2020 (Cth), which inserted Part VIIIC into the Family Law Act 1975 (Cth).

The Family Court of Western Australia confirms that Part VIIIC contains the superannuation splitting scheme for de facto couples.

The way this works is unusual, and it is the most WA-specific feature of these agreements.

Section 90YK of the Family Law Act provides that the part of a Western Australian financial agreement dealing with superannuation interests is a superannuation agreement for the purposes of Part VIIIC.

Section 90YD defines a Western Australian financial agreement as an agreement that is a financial agreement within the meaning of Part 5A of the Family Court Act 1997 (WA).

On the WA side, section 205ZPA of the Family Court Act 1997 (WA) allows a financial agreement to include an agreement dealing with superannuation.

So a single document made under state law carries a superannuation clause that takes its force from federal law.

That split is easy to get wrong, and it is one of the clearest reasons a WA agreement should not be adapted from a template written for another state.

What Does This Mean For Agreements Signed Before September 2022?

They may contain a superannuation clause that could not do what it was written to do.

An agreement drafted for a WA de facto couple before 28 September 2022 was prepared at a time when no splitting mechanism existed for them.

Some of those agreements treated superannuation as a financial resource, or offset it against other property, because that was the only approach available.

Others may have included a splitting clause that could not take effect as a binding split when it was signed.

Section 205ZPA applies to agreements made on or after the commencement day, so an older agreement may need to be replaced rather than simply relied on.

If the document predates that date and superannuation is a meaningful part of your asset pool, it is worth checking your agreement for errors.

The position available to you now is different from the position that existed when it was drafted.

Do The June 2025 Family Law Changes Apply To De Facto Couples In WA?

They apply to married couples in WA, and at the time of writing they do not reach WA de facto property cases.

The Family Law Amendment Act 2024 (Cth) commenced on 10 June 2025 and changed how property settlements are decided under the Family Law Act.

It set out a structured framework for dividing property, made the economic effect of family violence an express consideration, addressed wastage of assets and the treatment of liabilities, and introduced rules for companion animals.

Because those changes amend the Family Law Act, they apply to married couples wherever they live, including Western Australia.

De facto couples in WA sit in a different position, because their property matters are decided under the Family Court Act 1997 (WA).

That Act has not been amended to carry the same property provisions.

Western Australia did pass its own Family Court Amendment (Commonwealth Reforms) Act 2024, which received assent on 6 December 2024, but that Act deals with children’s matters, enforcement and court procedure rather than property division.

Until the state parliament makes matching property amendments, a de facto property case in Western Australia is decided under the framework that applied before June 2025.

This gap is worth understanding when you weigh an agreement against leaving matters to a court.

The default you are contracting out of is not the same default a married couple in Perth is contracting out of.

It is also a moving target, because the state parliament may bring the Family Court Act into line at some point.

An agreement that records the parties’ own terms reduces how much rides on that uncertainty.

What Makes A Binding Financial Agreement Binding In Western Australia?

Signing is not enough, and the requirements that make a binding financial agreement binding are strict.

For married couples, section 90G of the Family Law Act requires that the agreement is signed by all parties, and that before signing each party was provided with independent legal advice from a legal practitioner about the effect of the agreement on that party’s rights and about the advantages and disadvantages of making it at the time the advice was given.

Each party must also be provided with a signed statement from the practitioner confirming that the advice was given, and a copy of that statement must be given to the other party or their lawyer.

The agreement must not have been terminated or set aside.

For de facto couples in WA, the equivalent provision is section 205ZS of the Family Court Act 1997 (WA), which the Act itself notes as corresponding to section 90G.

The broad requirements are similar, in that each party needs their own lawyer and advice before signing, along with written confirmation from that lawyer that the advice was given.

The documentary formalities in the WA section are not word for word the same as the federal ones, which is another reason a WA agreement should be prepared against the WA Act.

One lawyer cannot advise both parties.

The certificate is not a formality, because it is the main evidence that the advice requirement was met.

For married couples, section 90G(1A) of the Family Law Act also lets a court declare an agreement binding despite a defect, where it would be unjust and inequitable not to.

When Can A Court Set Aside An Agreement?

Section 205ZV of the Family Court Act 1997 (WA) sets out when a court may set aside a de facto financial agreement, and the Act notes that it corresponds to section 90K of the Family Law Act.

General law principles apply on top of the statute, which is where the leading authority comes in.

In Thorne v Kennedy [2017] HCA 49, decided on 8 November 2017, the High Court set aside two agreements made under Part VIIIA of the Family Law Act.

The Court held unanimously that the agreements should be set aside for unconscionable conduct, and a majority also found undue influence.

Thorne v Kennedy is a federal case about a married couple, but the equitable principles it applied are not confined to the federal Act.

The circumstances that concerned the High Court, including the pressure created by presenting an agreement shortly before a wedding and the position of a party with no real ability to negotiate, arise just as easily in a WA de facto agreement.

Giving both parties genuine time, and full financial disclosure, is the practical answer.

What Happens If You Move Interstate?

A WA de facto agreement is made under state law, so moving changes which law would govern a future dispute.

A de facto couple who sign under Part 5A of the Family Court Act 1997 (WA) and later move to Victoria are moving into a jurisdiction where de facto financial matters fall under the Family Law Act.

The position for a couple who sign a federal de facto agreement elsewhere and then settle in Perth is not simply the mirror image, and needs its own advice.

The Family Law Act also has a provision, section 90UE, dealing with agreements made in non-referring states that become Part VIIIAB financial agreements, so a WA agreement is not necessarily left stranded when circumstances change.

Married couples are less exposed, because the Family Law Act follows them across state borders.

This does not mean an agreement stops working the moment you cross a border.

It does mean the document should be written with movement in mind.

If a move is likely, raise it while the agreement is being drafted rather than after it has been signed.

Reviewing an existing agreement after a permanent move is a sensible step, particularly where the original was prepared for the other regime.

Get Help With A Binding Financial Agreement In Western Australia

Binding financial agreements in Western Australia run on two separate tracks, and choosing the right one matters more here than anywhere else in the country.

Married couples are covered by Part VIIIA of the Family Law Act 1975 (Cth), de facto couples are covered by Part 5A of the Family Court Act 1997 (WA), and the time limits, section references and superannuation rules are different between them.

As binding financial agreement lawyers in Western Australia, my law firm can prepare an agreement drafted under the right Act for your circumstances, at a fixed fee agreed before the work starts.

Contact my law firm today by calling 1300-529-888.

Frequently Asked Questions

Do De Facto Couples In Western Australia Need A Different Binding Financial Agreement?

Yes. De facto couples in Western Australia make financial agreements under Part 5A of the Family Court Act 1997 (WA), not Part VIIIA of the Family Law Act 1975 (Cth). The relevant provisions are sections 205ZN, 205ZO and 205ZP. An agreement citing the federal sections points to a law that does not govern how the agreement is made.

Can De Facto Couples In WA Split Superannuation?

Yes, since 28 September 2022. Before that date they could not make a binding split of a superannuation interest. Part VIIIC of the Family Law Act 1975 (Cth) provides the scheme, and section 205ZPA of the Family Court Act 1997 (WA) allows a financial agreement to deal with superannuation, so a state agreement can carry a federal splitting clause.

How Long Do You Have To Apply For A Property Settlement In Western Australia?

A married person has 12 months from the date the divorce order takes effect, under section 44(3) of the Family Law Act. A de facto partner in Western Australia has two years from the end of the relationship, under section 205ZB of the Family Court Act 1997 (WA). The court can grant leave to apply late where hardship would be caused to a partner or a child.

Do The June 2025 Family Law Property Changes Apply In Western Australia?

They apply to married couples in Western Australia because they amend the Family Law Act 1975 (Cth). At the time of writing they do not reach de facto property cases in Western Australia, which are decided under the Family Court Act 1997 (WA). That state Act has not been amended to carry the same property provisions.

Does Each Party Need Their Own Lawyer For A WA Binding Financial Agreement?

Yes. Both the federal and Western Australian provisions require each party to receive independent legal advice before signing, covering the effect of the agreement on their rights and its advantages and disadvantages. Each party must also receive a signed statement from their own lawyer confirming that advice was given. One lawyer cannot advise both.

What Happens To A WA Agreement If You Move Interstate?

Moving changes which law would govern a future dispute. A de facto agreement made under the Family Court Act 1997 (WA) was drafted for a state regime, while de facto matters in other states are dealt with under the Family Law Act. Outcomes depend on residence and timing, so review the agreement after a permanent move.