Prenuptial agreements (BFAs) in Australia: are they enforceable — 2026 AU guide

In Australia, prenuptial agreements are known as Binding Financial Agreements (BFAs) and are governed by the Family Law Act 1975. When drafted correctly and with independent legal advice obtained by both parties, a BFA can be legally enforceable — but courts retain the power to set them aside under specific circumstances.

What is a Binding Financial Agreement (BFA)?

Many Australians use the term "prenuptial agreement" loosely, but the correct legal term under Australian law is a Binding Financial Agreement, or BFA. These agreements are created under Part VIIIA of the Family Law Act 1975 and allow couples to agree in writing on how their financial resources, property, and superannuation will be divided if their relationship breaks down.

BFAs are available to a wide range of couples, not just those who are engaged to be married. De facto couples — including same-sex couples — can also enter into financial agreements under the Act. Agreements can be made before a relationship begins, during it, or after separation. The one made before marriage is colloquially called a "prenup," but legally it operates as a BFA.

Unlike many other legal instruments, a BFA does not need to be approved or registered with a court to take effect. However, this also means that courts can scrutinise them closely if one party later seeks to have the agreement set aside.

What must a BFA include to be valid?

Validity is where many BFAs come unstuck. The Family Law Act 1975 sets out a strict checklist that must be satisfied for an agreement to be binding:

- The agreement must be in writing and signed by both parties. - Before signing, each party must receive independent legal advice from a separate, qualified Australian legal practitioner about the effect of the agreement on their rights and the advantages and disadvantages of making it. - After that advice is given, each lawyer must provide a signed statement confirming the advice was provided. - Those signed statements must be exchanged between the parties and attached to, or kept with, the agreement.

If any of these requirements are not met, the BFA is not considered binding. Courts have historically been strict about this, and even minor procedural oversights have led to agreements being declared unenforceable. This is why it is essential to work with an experienced family lawyer rather than using a generic template or attempting a DIY approach.

For guidance on finding a qualified practitioner, you can consult the Law Council of Australia — state and territory law societies and bar associations.

When can a court set aside a BFA?

Even a properly executed BFA is not absolutely untouchable. Section 90K of the Family Law Act 1975 lists the circumstances under which a court may set aside a financial agreement. These include:

- Fraud: If one party failed to disclose a material matter — such as significant assets or liabilities — at the time of signing. - Unconscionability or duress: If one party signed under pressure, was in a vulnerable emotional state, or was not given sufficient time to consider the agreement. - Impracticability: If circumstances have changed so dramatically that it would now be impractical to carry out the agreement. - Material change in circumstances relating to a child: If the agreement would cause hardship to a child of the relationship or to the carer of such a child. - Void, voidable or unenforceable: If the agreement would otherwise be void under general contract law principles.

Courts do not set aside BFAs lightly, but the case law over the years has shown that agreements are regularly challenged. Couples should view a BFA not as an iron shield but as a well-considered framework that reduces — rather than eliminates — dispute. The Federal Circuit and Family Court of Australia provides resources explaining how financial matters are handled when parties cannot reach an agreement.

How much does a BFA typically cost?

Because BFAs require independent legal advice for both parties and careful drafting by experienced practitioners, they are not inexpensive. The cost varies significantly depending on the complexity of the parties' financial circumstances, the number of assets involved, whether superannuation interests need addressing, and the solicitors engaged.

We are unable to provide a meaningful price range here without attaching authoritative sources to specific figures. For a realistic and up-to-date picture of legal costs in your state, consult our cost guide or speak directly to a family lawyer, who is obliged to provide a costs disclosure at the outset of your matter under solicitor conduct rules.

If cost is a concern, it is worth exploring whether you qualify for assistance through Legal Aid (state by state), though legal aid for BFA preparation may be limited depending on your circumstances and location.

BFAs versus consent orders: what is the difference?

A BFA is not the only way to formalise property arrangements in Australia. After separation, many couples instead apply for consent orders through the Federal Circuit and Family Court of Australia. Consent orders are approved by the court, which means a judicial officer must be satisfied the orders are just and equitable.

The key distinctions are:

For couples already separated or divorced, consent orders often provide greater certainty because a court has reviewed them. However, for those planning ahead — particularly those entering a relationship with significant pre-existing assets, a business, or an inheritance interest — a BFA remains a practical and widely used option.

If you are in Sydney and looking for representation, browse best family lawyers in Sydney for an independent overview of local practitioners.

Practical tips before signing a BFA

Getting a BFA right requires preparation and honest communication between partners. Consider the following:

- Start early. Attempting to finalise a BFA days before a wedding is a red flag courts take seriously. Ideally, the process should begin months in advance. - Full financial disclosure. Both parties should provide a comprehensive picture of their assets, liabilities, income, and financial commitments. Incomplete disclosure is one of the most common grounds for setting aside an agreement. - Separate lawyers for each party. This is a legal requirement, not a formality. Each lawyer acts only for their client and cannot provide advice to the other party. - Update your BFA when life changes. The birth of children, acquisition of major assets, or a significant change in one party's financial position may warrant revisiting the agreement. - Consider whether superannuation splitting provisions are needed. Superannuation is often overlooked but can be included in a BFA. A financial adviser familiar with superannuation splitting may also be helpful.

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Frequently asked questions

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Sources

- Federal Circuit and Family Court of Australia - Family Law Act 1975 — Australian Government Federal Register of Legislation - National Legal Aid — Legal Aid Australia (state by state) - Law Council of Australia — State and Territory Law Societies and Bar Associations

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Information in this article is general only and not legal advice. Verify the details with the linked sources or an appropriately qualified Australian professional before relying on them.

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