Tax debts are one of the most overlooked liabilities in an Australian property settlement. When a couple separates, attention typically goes to the family home, superannuation, and joint bank accounts. The balance owing to the Australian Taxation Office (ATO) often sits quietly in the background until it becomes a flashpoint in negotiations. Whether the debt belongs to one partner or both, it can directly affect what each party receives from the asset pool.
Tax debts are part of the asset pool
Under the Family Law Act 1975 (Cth), courts assess the full financial picture of a relationship. That picture includes liabilities, not just assets. A tax debt owed to the ATO at the time of separation is treated as a liability of the relationship and is factored into the net asset pool just like a mortgage or a credit card balance.
This applies whether the debt arose from a joint activity, such as a jointly owned investment property, or from one partner's individual income. The source of the debt matters, but it doesn't automatically decide who bears it in the final settlement.
Courts do distinguish between liabilities that benefited the relationship and those that didn't. A tax liability from a shared rental property is viewed very differently from a debt that arose because one partner failed to lodge returns for years without the other's knowledge. That said, even a unilateral debt can be absorbed into the pool rather than assigned entirely to one party.
Individual tax debts vs joint obligations
Some tax debts are strictly individual. If only one partner's name appears on the ATO account, the other partner has no direct legal obligation to the ATO. The debt belongs to the individual taxpayer. Full stop.
But in a property settlement, the court can still account for that debt when deciding on the overall split. If Partner A has a $40,000 personal tax debt, the court may reduce Partner A's share of the asset pool by that amount, or structure the settlement so Partner A retains assets sufficient to pay it. The settlement absorbs the liability even if the other partner never touches the money.
Joint tax obligations are less common in personal relationships but do arise in partnerships, jointly owned investment assets, or trust distributions. Where both names appear on an ATO liability, both partners share legal responsibility. That shared obligation is dealt with directly as a joint debt of the relationship.
How the ATO fits into the picture
It's worth being clear on one point. The ATO is not a party to your property settlement. A family court order dividing assets between two people does not bind the ATO. If Partner A is assigned the tax debt in a settlement and then fails to pay it, the ATO can still pursue Partner B for any joint liability. The settlement creates obligations between the two parties, not a shield against the ATO.
This is a critical distinction. It means that agreeing informally to let one partner "handle" a tax debt carries real risk. If that partner defaults, the ATO's recovery options aren't limited by what two separating people wrote in a consent order.
Rockwell Family Law Services advises clients to pay off or formally extinguish tax debts before or at the time of settlement wherever possible. Where that isn't feasible, the settlement structure needs to genuinely account for the risk of non-payment.
Tax debts from business income
When one partner is self-employed or runs a business, tax debts become more complicated. Business income tax, BAS obligations, and unpaid GST can all accumulate and may not be obvious at the time of separation. Business accounts are often a source of hidden or underestimated liabilities. As noted in our guide on how property settlement works when one partner is self-employed, income figures in these cases are routinely harder to verify, and the same applies to associated tax obligations.
Courts can order financial disclosure from both parties. This includes ATO notices of assessment, tax returns, and BAS statements. If a tax debt has been concealed or understated, that becomes a form of non-disclosure and can affect the credibility of the entire settlement.
Forensic accountants are sometimes engaged in these cases to reconstruct business tax liabilities accurately.
Debts that arose after separation
Tax debts incurred after separation are treated differently. Courts draw a distinction between liabilities that existed during the relationship and those that one party created post-separation. A partner who runs up a large tax debt after the couple has split may not succeed in having that debt included in the shared pool.
Timing matters. The date of separation is therefore an important anchor point in any property settlement involving tax liabilities. Rockwell Family Law Services recommends documenting the date of separation clearly and gathering ATO account information as of that date to avoid later disputes about what was owed and when.
Contributions and their effect on division
Beyond just identifying the debt, courts consider each party's contributions to the relationship and their future needs. A partner who managed household finances, lodged accurate tax returns, and ensured compliance may be viewed as having made a non-financial contribution. A partner whose recklessness or negligence created an avoidable tax liability may face an adverse adjustment in the settlement.
This intersects with how courts view waste. If a tax debt arose because one party failed to pay when funds were available, and those funds were instead spent on personal expenses, a court can treat that as financial waste and adjust the other party's share upward. Waste is not a simple concept in family law, but deliberate non-compliance with tax obligations has been recognised in this context.
For more context on how liabilities are generally divided after separation, see our article on what happens to debt in a property settlement.
Practical steps if tax debt is involved
Before entering negotiations, gather a complete ATO account statement for each partner. Confirm whether any debts are individual or joint. Check whether payment plans are in place and whether interest or penalties are accruing.
Tax debts that sit unresolved can grow quickly. The ATO charges the general interest charge on unpaid amounts, and that interest compounds daily. A $20,000 tax debt left unresolved for 18 months can become substantially larger by the time a settlement is finalised.
If a partner is on an ATO payment plan, the terms of that plan need to be disclosed and factored into cashflow projections for the settlement. A party who is committing $1,500 per month to an ATO debt has a materially different financial position from one who does not, and the settlement should reflect that.
Rockwell Family Law Services works with clients to identify all outstanding tax liabilities early, so the full financial picture is accurate before any agreement is reached. Settling without that clarity means the numbers are wrong from the start.