Two contracts on near-identical established houses in Maitland. One signed on 8 May 2026. One signed on 19 May 2026. Same price, same deposit, same loan structure, same weekly rent.

From 1 July 2027, those two properties will be treated differently. The only thing separating them is the date on the front page of the contract.

That date is 7:30pm AEST on 12 May 2026, and it is now settled law rather than proposal. Established residential dwellings acquired after that moment will no longer allow net rental losses to be offset against salary or other non-rental income. Properties held before it are unaffected, indefinitely.

Acquisition is measured by contract date, not settlement. An investor who exchanged on 8 May and settled in July is grandfathered. An investor who exchanged on 19 May and settled in June is not.

The cash-flow difference on a single property

Take a $700,000 established house, an $560,000 loan at 6.2 per cent, and rent of $560 per week.

Interest runs to roughly $34,700 a year. Rates, insurance, management and maintenance add around $6,000. Total holding costs of about $40,700 against rental income of $29,120 produces a net rental loss of roughly $11,600.

For the investor who exchanged on 8 May, that $11,600 continues to be deductible against salary. At a combined marginal rate of around 39 per cent, that is approximately $4,500 a year returning to them at tax time.

For the investor who exchanged on 19 May, that $4,500 stops arriving from 1 July 2027. On an identical asset, held identically, the after-tax holding cost is around $87 a week higher.

Both investors keep the current treatment until 30 June 2027. The divergence has a start date, not an immediate one.

What is not happening

Most of the alarm around this change overstates it in two specific ways.

The first is the idea that the deduction disappears. It does not. The net rental loss is quarantined rather than denied — it remains deductible against residential rental income, it can be applied against capital gains from residential property, and unused losses carry forward to future years. Interest on the loan is still fully deductible against the rent the property produces. What changes is that the loss can no longer reduce tax on wages.

For an investor building toward a portfolio that eventually runs cash-flow positive, the deduction is deferred rather than lost. For an investor holding a single property with no other rental income, the deferral has no practical value in the near term. Same rule, materially different consequence, and the difference is portfolio composition rather than the legislation.

The second overstatement is that existing portfolios are affected. They are not. An investor holding four established properties bought between 2015 and 2024 is in exactly the same position today as they were in April. Nothing about the way those properties are treated has changed.

Where this actually lands in a lending assessment

The tax outcome is a question for an accountant. What changes on the lending side is the input.

Many lenders include a negative gearing benefit when calculating an investor's assessable income for servicing — the tax saving generated by the rental loss is treated as income available to support repayments. Where a property no longer produces a loss deductible against salary, that input is no longer there to add back.

Some lenders include that benefit generously. Some apply it conservatively. Some do not include it at all. That divergence has always existed, and it is the reason the same investor can produce meaningfully different borrowing capacity across two calculators on the same day.

From July 2027, a further layer sits on top of it: portfolios will contain properties on both sides of the 12 May date. The assessment has to distinguish between them. How each lender handles a mixed portfolio — grandfathered properties alongside quarantined ones — is a policy question, and policy questions of this kind are rarely answered uniformly across the market.

None of this alters the mechanics already in place. Rental income is still shaded. Repayments are still assessed at a rate above the actual rate offered. The assessment rate does the heavy lifting on capacity, as it always has. The negative gearing input sits alongside those, and for some investors it will move.

The CGT change is a separate calculation

The two measures are routinely discussed as one thing. They are not.

The CGT reform replaces the 50 per cent discount with cost base indexation and a minimum 30 per cent tax rate on capital gains, applying to gains that accrue after 1 July 2027. It carries no 12 May cut-off, and it reaches well beyond residential property to CGT assets held by individuals, trusts and partnerships generally. The main residence exemption is unchanged.

Which means both investors in this scenario — the grandfathered one and the affected one — sit on exactly the same side of the CGT change. The contract date sorted them on negative gearing and did nothing on capital gains.

Eligible new builds are excluded from the negative gearing limitation. In the Hunter, that distinction separates established stock in Cessnock, Maitland and Raymond Terrace from the newer supply in the Thornton and Chisholm corridors.

The decision this affects

For investors who bought before Budget night, this is not a reason to review anything. The position is unchanged.

For investors considering their next purchase, the relevant question is not whether the rules are fair. It is what the servicing calculation looks like once one property in the portfolio contributes a tax benefit and another does not — and whether the deferred loss has anywhere useful to go.

Understanding how that flows through an assessment before signing a contract is what separates a considered next purchase from a surprised one.