On 4 August 2026, Treasury released the draft legislative instrument setting out the "apportioning method" the formula-based alternative to a market valuation flagged under the Treasury Laws Amendment (Tax Reform No. 1) Act 2026.
The Details
- The draft instrument is the Income Tax Assessment (Method for Apportioning Capital Gains and Capital Losses) Determination 2026.
- It applies to real property and other assets without a readily ascertainable market value.
- The approach can only be applied at the time of an asset's actual future sale. It is not a value you can obtain today or as at 1 July 2027.
- The method calculates a notional value at 1 July 2027 by working backwards from the eventual sale price, using a constant compounding growth rate applied across the full holding period.
- Consultation on the draft closes 21 August 2026. It is not yet final law.
The 1 July 2027 deemed disposal and reacquisition date, and the 30 June 2027 asset-scope reference date, are unchanged by this release.
Our Position
The apportioning method assumes a constant, straight-line rate of growth over the entire time an asset is held. Property doesn't move in a straight line. Depending on how a property's value tracked against that assumption, the formula can just as easily produce a higher taxable gain as a lower one.
Because it can only be calculated once an asset is sold, it doesn't give a property owner certainty at 1 July 2027, it gives certainty only in hindsight, potentially years or decades later, using evidence that gets harder to source and easier to dispute the longer it is left.
The risk is greatest for multi-property portfolios, commercial and rural holdings, and assets held in complex structures, where a single average growth rate is least likely to reflect what actually happened.
A market valuation completed as at 1 July 2027, prepared by a qualified valuer with current evidence and a defensible methodology, remains the most reliable way to know your position. It's based on the property as it actually was at the time, not a formula's assumption about how it grew.
Lock in your 1 July 2027 valuation now
To help you plan ahead of the 1 July 2027 changeover, Acumentis is opening early bookings. A 20% deposit secures your valuation slot and today's pricing. Here's what you can lock in now:
- Valuation booking slot. A confirmed booking in our schedule around 1 July 2027, ahead of the rush.
- Today's price. Locked in now, before demand-driven pricing takes hold.
- Priority access to a valuer who knows the local market.
The valuation date remains 1 July 2027 as required by law. Booking early doesn't change that, it protects your place in the schedule and your price ahead of the rush expected closer to the date.
You'll receive:
- A defensible, valuer-signed figure
- A locked-in booking and price, ahead of the demand curve
- One national firm, with local valuers in every market you hold property
Single residential properties start from $600 + GST. Portfolios and specialised properties are quoted individually.
Secure your 1 July 2027 CGT valuation →
This update is provided for general information only and does not constitute financial, tax or legal advice. Acumentis is not licensed to provide financial or tax advice. Property owners should speak with their accountant or financial adviser about how these changes apply to their individual circumstances.