Lifestyle clauses are the provisions in a prenup that go beyond money. They attempt to set rules about fidelity, social media use, weight, screen time, or how often a couple visits relatives. Some couples treat them as a form of mutual accountability. Others see them as a way to attach financial consequences to specific behaviour. In Australia, the legal reality is more restrictive than either group tends to expect.
What a lifestyle clause actually is
A lifestyle clause is any provision in a binding financial agreement (BFA) that links a financial outcome to personal conduct. Common examples include a clause reducing a partner's entitlement if they commit adultery, a clause awarding a bonus amount if the marriage reaches a specified anniversary, or a clause tying financial outcomes to sobriety. These aren't abstract. People draft them and pay lawyers to include them. The question is whether they hold up under Australian law.
It's worth being clear about one thing first: the term "prenup" in Australia refers to a binding financial agreement made under the Family Law Act 1975. That Act sets the boundaries for what a BFA can legally cover, and those boundaries don't map neatly onto what couples sometimes want lifestyle clauses to do.
What Australian law permits
The Family Law Act allows a BFA to deal with how property and financial resources are to be divided if the relationship breaks down. It can also address spousal maintenance. Those two categories are the authorised scope of a BFA. Lifestyle clauses that directly alter financial entitlements based on conduct can technically sit within that scope if they're structured as financial provisions rather than behavioural mandates.
A clause that says "if either party commits adultery, the other party receives an additional $50,000" is attempting to attach a financial consequence to conduct. Courts have looked at similar provisions in other jurisdictions with scepticism, and Australian courts retain the power to set aside a BFA on grounds including unconscionability. A clause that appears grossly one-sided, punitive, or oppressive can become a target for challenge. If you're considering how to protect your assets with a prenup in Australia, behavioural clauses add legal risk rather than removing it.
What courts will not enforce
Australian family law courts don't enforce provisions that purport to regulate personal behaviour without a financial consequence, or where the financial consequence is a disguised penalty for lifestyle choices. Three categories consistently fail:
- Clauses dictating personal habits (diet, exercise, social media use) with no clear financial tie.
- Clauses that purport to regulate parenting behaviour before any children exist. Courts will not allow a BFA to pre-determine parenting arrangements or child support outcomes, both of which fall outside the permitted scope of a BFA under the Act.
- Clauses that are so vague they cannot be applied, for example a provision requiring a partner to "maintain a healthy lifestyle" without defining what that means or what the financial consequence is.
The enforceability question also intersects with the broader rules that govern what makes a binding financial agreement enforceable. A BFA that contains lifestyle clauses is still subject to all the same formal requirements: independent legal advice, written certification, and proper execution. A lifestyle clause doesn't excuse non-compliance with those requirements, and a BFA that fails on those grounds fails entirely, not just in the lifestyle section.
The fidelity clause problem
Fidelity clauses are the most common lifestyle provision people request. The instinct makes sense: infidelity causes real harm, and some people want the agreement to acknowledge that. But fidelity clauses create a specific legal problem in Australia. To trigger the clause, one party would need to prove infidelity to a legal standard. That means contested factual hearings, invasive evidence, and significant legal costs. Courts are not eager to become arbiters of marital fidelity, and judges have broad discretion to decline enforcement of clauses that would require that kind of inquiry.
There's also a practical problem. A fidelity clause that reduces one partner's financial entitlement significantly may be challenged as unconscionable, particularly if it was inserted into an agreement where one party had less bargaining power. Unconscionability is one of the grounds on which a court can set aside a BFA under section 90K of the Family Law Act.
Sunset and milestone clauses: a different case
Not all conduct-adjacent clauses are lifestyle clauses in the problematic sense. A clause that increases one partner's entitlement if the marriage reaches 10 or 20 years is a time-based financial provision. Courts treat these differently from behavioural clauses because they don't require any factual investigation into personal conduct. They're also consistent with the Act's permitted scope: they determine how property is divided based on an objectively verifiable condition. If a couple's circumstances change significantly, it may be worth reviewing the agreement, since how long a prenup lasts in Australia depends partly on whether it continues to reflect what's fair given those changes.
Why people still include lifestyle clauses
Lifestyle clauses persist in BFAs partly because couples want them and partly because no Australian court has issued a definitive ruling striking them down as a category. That ambiguity gives some lawyers and clients confidence to include them. The practical reality is that most BFAs never reach a court. If both parties are committed to the agreement when a relationship ends, lifestyle clauses don't get tested. It's only when one party contests the BFA that the clause's vulnerability becomes clear.
Rockwell Family Law Services advises clients to focus lifestyle clause discussions on the financial provisions the Act actually supports. Clear, specific, and financially grounded provisions offer real protection. Vague or punitive behavioural clauses often do the opposite: they give the other party a legitimate argument for challenging the whole agreement.
Getting the agreement right
If you want a prenup that includes any conduct-adjacent provisions, the drafting has to be precise. Vague intentions translate into unenforceable clauses. A well-drafted BFA separates what the law supports from what a couple might wish it supported, and that distinction saves both parties from expensive litigation later.
Rockwell Family Law Services works with clients across Australia to draft binding financial agreements that are built to hold. Contact Rockwell Family Law Services today to discuss your situation and get advice tailored to your specific circumstances.