Who this is for
People in Western Australia who are already in a de facto relationship, or who are not yet de facto but intend to marry, and who want one agreement that remains effective if they later marry.
What this sheet covers
- What a hybrid (blended) Binding Financial Agreement is
- Why people choose a hybrid agreement
- The small residual risk in WA and why it’s considered low
- Practical requirements that make any agreement more likely to be enforceable
- Alternatives to a hybrid agreement
Two legal systems and the different “gateways” for financial agreements
Australia runs two parallel systems for couples based in Western Australia:
- Western Australia (WA statute): de facto relationships are under the Family Court Act 1997 (WA), Part 5A, which allows financial agreements before, during and after a de facto relationship.
- Commonwealth (federal statute): marriages are under the Family Law Act 1975 (Cth), which allows financial agreements before marriage (s 90B), during marriage (s 90C) and after divorce (s 90D).
Why this matters
There isn’t “one BFA for everyone”. The correct gateway depends on your status (de facto or married) when you make the agreement and the law that applies to that status. Using the wrong gateway means the agreement may not prevent the court using its usual powers later.
Tailoring to before-separation planning
To keep continuous protection now and after a future wedding, the options are:
- a hybrid (one document containing a WA de facto component and a Commonwealth pre-marriage component), or
- a two-step approach (a WA de facto agreement now, plus a Commonwealth agreement before or during marriage).
Note: In every State and Territory except Western Australia, both de facto and married couples are covered by the same federal law (the Family Law Act 1975 (Cth)). That makes a blended agreement simpler there. WA is different: de facto is under the Family Court Act 1997 (WA) and marriage is under the Family Law Act 1975 (Cth), so a blended document must bridge two separate laws, which is why there is a small residual uncertainty in WA and why careful structuring (hybrid or two-step) matters.
What is a hybrid (blended) Binding Financial Agreement?
A hybrid BFA is a single written agreement drafted to work under both systems:
- While de facto: it operates as a WA de facto financial agreement under Part 5A of the Family Court Act 1997 (WA).
- If you marry later: the same document also operates as a Commonwealth pre-marriage financial agreement under section 90B of the Family Law Act 1975 (Cth).
In short, one agreement is intended to apply during your de facto relationship and continue after marriage, without signing a new agreement at the wedding.
Why do people choose a hybrid agreement?
- Continuity: one document designed to apply now and after marriage.
- Convenience: avoids organising a second agreement right before or after the wedding.
- Certainty: consistent rules across the relationship instead of separate documents.
The small residual risk in Western Australia (and why it is low)
Courts in the Eastern States have upheld blended agreements under the federal Act (e.g. Piper & Mueller [2015] FamCAFC 241), showing one document can perform more than one function under that Act when formalities are met.
WA is different because de facto law is in a separate WA statute. There is no reported WA case that directly confirms a single document combining a WA de facto agreement with a Commonwealth pre-marriage agreement. That creates a small residual uncertainty.
However, WA’s provisions were modelled on the federal regime and WA courts regularly look to federal cases for guidance. On that basis, the risk is generally considered low.
Bottom line: a hybrid is commonly used for clients who want a document to continue after marriage; the risk in WA is small but real.
Alternatives to a hybrid agreement
- De facto-only now + Commonwealth agreement later
- Sign a WA de facto agreement now.
- To keep protection after marriage, also sign a Commonwealth agreement before the wedding (s 90B) or during marriage (s 90C).
- Pros: orthodox; avoids the novelty of a blended document.
- Cons: the de facto agreement won’t continue after marriage unless you complete the second agreement; possible gap if it’s delayed or not signed.
- Commonwealth pre-marriage agreement only (s 90B)
- Suitable if marriage is imminent and de facto coverage is not required.
- Pros: simpler if you only want protection after marriage.
- Cons: no protection while de facto and none if you never marry.
Why a WA de facto-only agreement won’t protect you after you marry
A WA de facto agreement is made under Part 5A (WA) and applies while you are de facto. Once you marry, property and maintenance are governed by the Commonwealth Act for married couples. Because the statutes and gateways are different, a de facto-only agreement does not automatically become a marriage agreement.
In practice
- After marriage, a court applies the Commonwealth law. A WA de facto agreement does not satisfy the Commonwealth financial-agreement requirements, so it generally won’t control the outcome.
- General contract law won’t convert a de facto agreement into a marriage agreement. These agreements limit the court’s powers only when made through the correct statutory pathway.
- To maintain protection across the wedding, use a hybrid or sign a separate Commonwealth agreement at the right time.
Example
Alex and Sam sign a WA de facto-only agreement, then marry and later separate. The court applies Commonwealth law for married couples. The earlier WA agreement does not meet Commonwealth requirements, so it does not govern the division.
Why a Commonwealth pre-marriage agreement won’t protect you if you separate while still de facto (or if you never marry)
A pre-marriage (s 90B) agreement is a Commonwealth instrument intended to apply because you marry. It is not a WA de facto agreement.
Consequences
- If you separate before the wedding, you are still de facto. WA de facto law applies, and a s 90B agreement does not control a WA de facto separation.
- If you never marry, the s 90B agreement never takes effect for its intended purpose and does not convert into a WA de facto agreement.
Example
Priya and Jordan sign a s 90B agreement intending to marry next year but separate beforehand. Their matter is a WA de facto property issue. The s 90B agreement does not provide coverage.
Additional option: Hybrid now, then “during-marriage” agreement to replace it after the wedding
If you want coverage now and to fully lock things down once you’re married, you can use a two-stage “belt and braces” approach:
- Stage 1 — Now (before marriage): sign a hybrid agreement so you’re protected while de facto and, if you marry, there is continuity at the wedding.
- Stage 2 — After you marry: sign a “during-marriage” financial agreement (under the Commonwealth law) that expressly replaces/supersedes the marriage component of the hybrid. This can:
- reuse the same wording from your hybrid (with any updates), and
- include a termination/supersession clause so the new during-marriage agreement clearly terminates the earlier marriage component of the hybrid and becomes the operative agreement going forward.
Why choose this:
- Gives you immediate protection now, plus maximum certainty once you’re married.
- Minimises the small WA uncertainty by putting a fresh, stand-alone during-marriage agreement in place under the federal Act.
How it works in practice:
- We draft and sign the hybrid now.
- Shortly after the wedding, you sign a during-marriage agreement that:
- restates or updates your terms (we can lift most clauses from the hybrid), and
- includes a clear termination/supersession clause so the new agreement replaces the earlier marriage component of the hybrid.
- Both parties receive independent legal advice for each agreement, and the lawyer certificates are exchanged and kept with the documents.
Note: You can keep the structure and commercial deal the same; we mainly adjust the operative parts and certificates to meet the during-marriage gateway and include the termination/supersession language.
Important disclaimer
This information sheet provides general information only. It is not legal advice. Please obtain specific legal advice before signing or relying on any financial agreement.