A “50/50 prenup” is commonly requested by couples seeking certainty as to the division of assets in the event of separation.
In Australia, such an arrangement can be implemented through a Binding Financial Agreement. However, enforceability is not determined by the label “50/50”, but by strict compliance with legislative requirements and the surrounding circumstances in which the agreement is made.
At Adams United Lawyers, we advise on and prepare Binding Financial Agreements that are structured to withstand legal scrutiny, including equal division models where appropriate.
For a general overview, refer to:
/binding-financial-agreement-australia
Legislative Framework
Financial agreements entered into prior to marriage or de facto relationship are governed by the Family Law Act 1975, including but not limited to sections 90B, 90C and 90D (and equivalent provisions for de facto relationships).
To be binding, an agreement must:
- Be in writing and signed by both parties
- Contain a statement confirming that each party has received independent legal advice as to the effect of the agreement and the advantages and disadvantages of entering into it
- Be accompanied by signed certificates of independent legal advice
- Not have been terminated or set aside
Failure to strictly comply with these requirements will render the agreement vulnerable to challenge.
Nature of a 50/50 Division Clause
A 50/50 clause typically provides that, upon breakdown of the relationship, the net asset pool (as defined within the agreement) is to be divided equally between the parties.
However, the legal effect of such a clause depends on:
- The definition of the asset pool (including whether pre-existing assets are included or excluded)
- The treatment of future acquisitions and liabilities
- The interaction with superannuation interests
- The clarity and internal consistency of the drafting
A superficially simple “equal division” clause, if poorly defined, may give rise to ambiguity and subsequent dispute.
Enforceability and Grounds for Challenge
A Binding Financial Agreement, including one providing for a 50/50 division, may be set aside under section 90K (or equivalent provisions) in circumstances including:
- Fraud, including non-disclosure of material financial matters
- The agreement being void, voidable or unenforceable
- Circumstances of duress, undue influence or unconscionable conduct
- Material change in circumstances relating to the care, welfare and development of a child
- Impracticability of carrying out the agreement
The existence of a 50/50 division does not protect the agreement from challenge if these factors are present.
Comparison with the Court’s Discretionary Framework
Absent a Binding Financial Agreement, the court applies a structured four-step process, including:
- Identification and valuation of the asset pool
- Assessment of contributions (financial and non-financial)
- Consideration of future needs factors
- Determination of a just and equitable outcome
There is no presumption of equality. Outcomes frequently depart from a 50/50 division depending on the circumstances.
A properly drafted financial agreement allows parties to contract out of this discretionary framework, subject to compliance with the Act.
For comparison:
/binding-financial-agreement-vs-consent-orders
Appropriateness of a 50/50 Structure
A 50/50 model may be appropriate in circumstances where:
- The parties intend to contribute broadly equally over the course of the relationship
- There is no significant disparity in the initial financial position
- The parties seek certainty and simplicity over future adjustment arguments
However, where one party has substantial pre-existing assets, inheritance expectations, or business interests, a strict equal division may not reflect a commercially or legally appropriate outcome.
In such cases, alternative structuring should be considered.
Drafting Risks and Common Deficiencies
In practice, agreements purporting to provide for equal division frequently fail due to:
- Inadequate or incomplete financial disclosure
- Inconsistent or poorly defined asset schedules
- Failure to address future contingencies (including children, illness or income disparity)
- Defective independent legal advice processes
- Use of a template or non-compliant documents
These deficiencies materially increase the risk of the agreement being set aside.
Professional Process and Compliance
At Adams United Lawyers, the preparation of a Binding Financial Agreement involves:
Initial Consultation
Detailed assessment of the parties’ financial circumstances, intentions and risk profile.
Tailored Drafting
Preparation of an agreement addressing asset identification, division mechanisms, contingencies and compliance requirements.
Independent Legal Advice
Each party must obtain independent legal advice. We may provide a contact upon request; however, independence is strictly maintained.
Execution
Completion of the agreement in accordance with statutory requirements, including certification of advice.
Fixed Fee Structure
Drafting: $2,200 (inclusive of GST)
Includes consultation, drafting, amendments, liaison and execution guidance.
Independent Legal Advice (Review): $990 (inclusive of GST)
Includes consultation, written advice and certification.
Jurisdictional Coverage
We act for clients throughout Australia, including Queensland, New South Wales, Victoria, Western Australia and the Australian Capital Territory.
All consultations are conducted remotely.
Conclusion
A “50/50 prenup” is legally permissible under Australian law. However, enforceability depends not on the concept of equality but on the quality of drafting, compliance with statutory requirements, and the absence of vitiating factors.
Parties seeking certainty should obtain properly structured legal advice before entering into any such agreement.
