A prenup in Australia is not a single document you can download and sign over a weekend. It is a formal legal instrument known as a binding financial agreement (BFA), governed by the Family Law Act 1975. Getting one right takes time, the right legal advice, and a clear understanding of what you want to protect. This guide walks you through each stage of the process so you know exactly what to expect.
What a prenup actually is in Australian law
The word "prenup" is shorthand. In Australia, the formal term is a binding financial agreement made before a marriage or de facto relationship commences. The agreement sets out how property and financial resources will be divided if the relationship breaks down. It can also deal with spousal maintenance. What it cannot do is make decisions about children: parenting arrangements are handled separately by the courts and are always assessed against the best interests of the child at the time of separation. For a detailed breakdown of what these agreements cover, see our guide to what a prenup can and cannot do in Australia.
Step 1: decide what you want to protect
Before you call a lawyer, think carefully about your financial picture. List the assets you are bringing into the relationship: property, savings, superannuation, shares, business interests, and any inheritances you expect to receive. Also consider any debts. The clearer you are about what matters to you, the more focused and cost-effective the drafting process will be. Couples who arrive at a lawyer without a clear idea of their goals often spend more time and money working through issues that could have been resolved beforehand.
Step 2: each party must have independent legal advice
This is the requirement that catches people off guard. Under Australian law, a binding financial agreement is only enforceable if each party received independent legal advice from a separate, qualified lawyer before signing. Your lawyer must advise you in writing about the effect of the agreement on your rights and the advantages and disadvantages of making it. The same lawyer cannot act for both parties. Attempting to share a lawyer or skip this step will render the agreement void. If you are unsure why independent advice matters so much, our article on what makes a binding financial agreement enforceable explains the full legal criteria.
Step 3: choose a family lawyer with BFA experience
Not every family lawyer drafts BFAs regularly. Look for someone who specialises in prenuptial and financial agreements, not just general family law. A lawyer experienced in BFAs will know how to draft clauses that are clear, unambiguous, and less likely to be challenged later. Ask about their experience, the typical timeline they work to, and how they handle negotiations if your partner's lawyer raises concerns about specific terms.
Step 4: disclose your finances fully
Both parties must make full and frank disclosure of their financial circumstances. This means listing all assets, liabilities, income, and any significant financial interests. Concealing assets or understating liabilities is not just unethical: it can be grounds for a court to set aside the agreement later. Keep records of everything you disclose and ask your lawyer to document the disclosure process carefully.
Step 5: negotiation and drafting
Once both parties have lawyers and disclosure is complete, the drafting begins. Your lawyer will prepare an initial draft based on your instructions. The other party's lawyer will review it and may propose amendments. This back-and-forth is normal and healthy. A well-negotiated agreement is far more likely to hold up than one that was rushed or one-sided. Expect at least a few rounds of revisions before both lawyers are satisfied.
The timeline for drafting and finalising a BFA typically runs between four and eight weeks, though complex financial arrangements or disagreements between the parties can stretch this out. Starting the process well before the wedding or the relationship formalises is strongly advisable. Last-minute agreements signed under pressure are a common reason for challenges down the track.
Step 6: both parties sign, with certificates attached
Once the final document is agreed, each party signs it in the presence of their respective lawyers. Each lawyer then signs and attaches a certificate confirming that they provided the required independent legal advice. Without these certificates, the agreement does not meet the statutory requirements and will not be enforceable. Keep the original signed documents in a safe place. Your lawyer will also retain a copy.
Step 7: store the agreement securely
A BFA does not need to be registered with any court or government body. However, you should store it somewhere accessible and ensure both parties know where the document is held. If you update your will, review other estate planning documents, or acquire significant new assets after signing, it is worth revisiting the agreement with your lawyer to assess whether it still reflects your intentions.
How much does a prenup cost?
The cost depends on the complexity of your assets and the amount of negotiation involved. Simple agreements with straightforward asset lists tend to cost less than arrangements involving businesses, trusts, or overseas property. Both parties will have their own legal fees to pay. For a realistic breakdown, see our dedicated article on how much a prenup costs in Australia.
Can you get a prenup if you are already in a relationship?
Yes. A BFA can be made at any point: before a relationship begins, during a marriage or de facto relationship, or at the time of separation. A prenup made during a relationship is sometimes called a postnup, but the legal requirements are the same. The key is that the agreement must be entered into freely, with full disclosure and independent legal advice on both sides.
What can make a prenup fail?
Australian courts have set aside BFAs for a range of reasons, including fraud, duress, unconscionable conduct, and failure to disclose assets. Agreements that were signed at the last minute without genuine opportunity for reflection have also been challenged successfully. The requirements under the Family Law Act are strict precisely because these agreements can have significant long-term financial consequences for both parties. Getting the process right from the start is the most effective protection you have.
A prenup is a practical tool, not a sign of distrust. When prepared properly, it gives both people clarity about their financial position and reduces the potential for costly disputes if circumstances change. Starting early, choosing experienced lawyers, and being honest about your finances are the foundations of an agreement that will actually hold up when it matters.