When couples think about prenups, they focus on assets: the house, the investment portfolio, the superannuation. Business debts rarely make the list. But a business that carries substantial liabilities at the time of separation can generate financial fallout that a well-drafted prenup is perfectly positioned to address. Under the Family Law Act 1975 (Cth), a binding financial agreement can deal with both property and financial resources, and debt falls squarely within that scope.
Why business debts matter in a relationship breakdown
A business operated by one or both partners during a relationship sits inside the asset pool at separation. What most people don't realise is that the liabilities attached to that business sit there too. A business loan, a tax debt, an unpaid supplier account, or a director's guarantee can all become points of dispute when a relationship ends. Courts look at the net value of the business, not just the upside, so a partner who contributed financially to a business's growth can also be drawn into its debts.
This matters more when only one partner runs the business. The other partner may have supported the business indirectly, whether through income contributions, domestic labour that freed up the operator's time, or direct financial support during lean periods. That indirect contribution can give rise to a claim over the business, including a share of responsibility for its liabilities.
What a prenup can actually do with business debt
A binding financial agreement can specify that the debts of a business owned or operated by one partner remain solely that partner's responsibility in the event of separation. It can also set out which debts are joint, how they will be divided, and in what order liabilities will be addressed before any asset split takes effect. Rockwell Family Law Services advises clients to list specific loan accounts, credit facilities, and director's guarantees by name wherever possible, rather than using broad language that courts may interpret narrowly.
The agreement can go further and address future business debts incurred up to the date of separation. This is particularly useful for business owners who expect to take on commercial finance to grow the business. A well-drafted clause can draw a clear line: debts incurred to grow the business during the relationship remain the business owner's liability, and the other partner's entitlements are calculated from the net equity position at a defined point in time. If you want to understand the broader picture of what these agreements cover, the article on what a prenup can and cannot do in Australia sets out the full scope.
Personal guarantees: the overlooked problem
Director's guarantees deserve special attention. When a business owner signs a personal guarantee for a commercial loan, the liability moves from the company to the individual. If that individual is married or in a de facto relationship, the guarantee can affect the asset pool available for division at separation. A prenup that doesn't account for existing or future guarantees leaves a significant gap.
Rockwell Family Law Services recommends disclosing all current guarantees as part of the financial disclosure process when the agreement is being drafted. Non-disclosure is one of the most common grounds on which a binding financial agreement is later challenged or set aside. A guarantee that was known at the time but not included in the schedule of liabilities can undermine the entire agreement.
The link between business debts and asset protection
Business debts and business assets are two sides of the same problem. A prenup that protects a business from property claims is only half the job if it doesn't also clarify what happens to the debts that financed that business. For example, a prenup might specify that a partner's existing business is excluded from the asset pool, but if the business was partly funded by joint savings or a joint loan, those liabilities need to be resolved separately. The article on whether a prenup can protect a business in Australia covers the asset side of this equation in detail.
Getting both sides right requires a clear picture of the business's financial position at the time the agreement is signed. That means financial statements, loan schedules, and details of any contingent liabilities. A prenup built on a snapshot of the business at a specific date gives both parties a fixed reference point if a dispute arises years later.
When business debts arise after the agreement is signed
Businesses change. A prenup signed when the business was debt-free may look very different after a commercial expansion, a rough trading year, or a global disruption. Australian courts will generally apply the terms of the agreement to the circumstances at separation, but gaps in drafting create room for argument. A clause that refers only to debts existing at the date of signing will not automatically capture debts incurred later, unless the agreement is drafted to address that possibility.
Rockwell Family Law Services recommends reviewing any prenup that involves a business at least every three to four years, or whenever the business takes on significant new financing. This isn't about rewriting the agreement every time. It's about confirming that the language still reflects the parties' intentions given how the business has evolved.
Enforceability: what makes the debt provisions stick
A binding financial agreement covering business debts is only enforceable if it meets the formal requirements of the Family Law Act. Both parties must receive independent legal advice before signing. The agreement must be signed voluntarily, without duress or undue influence. Full and frank financial disclosure is not optional: both parties need to know what debts exist before they can meaningfully agree on how to treat them.
Courts have set aside agreements where one party concealed a liability that would have materially affected the other's decision to sign. A business debt that wasn't disclosed is a strong candidate for that kind of challenge. Structuring the agreement correctly from the start is the only reliable way to make the debt provisions hold.
Rockwell Family Law Services works with business owners and their partners to draft binding financial agreements that address both assets and liabilities with the specificity that Australian courts expect. If your business carries debt, or if you expect it to, that conversation needs to happen before you sign.