If you are entering a marriage or de facto relationship with significant assets, a prenup can provide real financial protection. Under Australian law, a prenuptial agreement is formalised as a binding financial agreement (BFA) under the Family Law Act 1975. When properly drafted, it can protect property, businesses, investments, and inheritances from being divided if the relationship ends. But the protection is only as strong as the agreement behind it, and getting it wrong can mean the document is set aside entirely.
What assets can a prenup protect?
A prenup in Australia can cover a wide range of assets, provided those assets are clearly identified and the agreement deals with them in a lawful way. Common assets people seek to protect include:
- Real estate owned before the relationship began
- Business interests, shares, or partnerships
- Investment portfolios and superannuation entitlements
- Inheritances, gifts, or family trust distributions
- Savings, vehicles, and personal property of significant value
The agreement can also address how assets acquired during the relationship will be treated. This is particularly useful for couples who expect one partner to receive a future inheritance or who plan to start a business together. For a more detailed look at the scope of protection, see our guide on what a prenup can and cannot do in Australia.
The legal requirements that determine whether protection holds
A prenup does not protect your assets simply by existing. Under the Family Law Act 1975, a binding financial agreement must satisfy strict formal requirements, or a court can set it aside. Every agreement must:
- Be in writing and signed by both parties
- Be accompanied by a statement of independent legal advice for each party
- Be signed by the lawyers confirming that advice was given before the agreement was signed
- Not have been entered into under duress, fraud, or through a material misrepresentation
Each party must receive independent advice from a separate lawyer. Both parties must understand the nature and effect of the agreement before signing. If these requirements are not met, the agreement is vulnerable to challenge regardless of what it contains. Our article on what makes a binding financial agreement enforceable covers these requirements in full detail.
Timing: when should you put a prenup in place?
The most straightforward time to enter a prenup is before a marriage or de facto relationship begins. Australian law does, however, allow agreements to be made during a relationship or even after separation. Each stage has different legal implications, and agreements made under time pressure (for example, days before a wedding) carry a higher risk of being challenged on the grounds of duress or inadequate advice.
Ideally, both parties should begin discussions and seek legal advice well before any milestone date. A realistic lead time is three to six months, particularly where the assets involved are complex or where one party needs time to properly understand the terms. Rushing this process is one of the most common reasons a prenup fails to hold up when tested.
Protecting a business specifically
Business owners often have the most to lose if a relationship breaks down without any agreement in place. A court can treat a business as part of the property pool, which may result in a forced sale or a buyout obligation at a difficult time. A well-drafted prenup can exclude the business from the pool entirely, cap the other party's interest at a fixed amount, or set out a clear valuation methodology to avoid disputes over what the business is worth at the time of separation.
Business protection clauses need careful drafting. They should account for growth in the business value over the course of the relationship, contributions made by both parties, and any intermingling of business and personal finances. A vague or poorly structured clause is easy to challenge.
What a prenup cannot do
Even a properly executed prenup cannot override everything. There are limits to what Australian law allows these agreements to cover. A prenup cannot:
- Determine parenting arrangements or child custody
- Remove a party's right to seek child support
- Be used to perpetrate fraud against a third party
- Deal with property that is not owned by either party at the time of signing
Courts will also look at whether the agreement was fair and reasonable at the time it was made. An agreement that leaves one party in genuine hardship may be set aside under section 90K of the Family Law Act 1975, even if all the formal requirements were technically met.
How to make your prenup as strong as possible
The single most effective thing you can do is engage experienced family law practitioners, one for each party, who genuinely understand binding financial agreements. Beyond that, the following steps significantly reduce the risk of a successful challenge:
- Full financial disclosure: both parties must be aware of each other's assets, liabilities, and financial position. Concealing assets is a ground for setting aside the agreement.
- Plain language explanations: both parties should understand what they are agreeing to, not just in legal terms but in practical terms.
- Review it periodically: a prenup drafted before children are born, or before a business grows substantially, may no longer reflect the reality of the relationship. Reviewing it every few years keeps it relevant.
- Avoid last-minute signing: any sign of pressure or urgency around the signing process invites scrutiny from a court.
Getting started
Protecting your assets with a prenup in Australia is achievable, but it requires proper legal advice, time, and transparency from both parties. The process is more structured than many people expect, and the cost of getting it right is far lower than the cost of litigation if the relationship breaks down without one in place. If you are considering a prenup or want to understand how a binding financial agreement could work for your situation, speaking with an experienced family lawyer is the right first step.