On 1 July 2027, capital gains tax changes shape. What survives is what you can prove.
The 2026 tax reform is law. It replaces the CGT discount with cost-base indexation, and it applies through a deemed disposal of every in-scope asset held on 1 July 2027 — whenever that asset was acquired. This page explains the mechanism and what it makes valuable. It computes nothing, asks you nothing, and reaches no conclusion about you or any property. That is deliberate, and the last section says why.
What is now law
The Treasury Laws Amendment (Tax Reform No. 1) Act 2026 (No. 49 of 2026) and its Rates Amendment (No. 50) received Royal Assent on 26 June 2026. The open question about this reform is repeal, not passage.
From 1 July 2027 the 50% CGT discount gives way to cost-base indexation with a 30% minimum rate. The calculation changes shape: what you paid, when, and what you added to the asset move from background detail to the centre of the arithmetic.
The transition works by deeming every in-scope asset held at 1 July 2027 to be disposed of at that date — whenever it was acquired. There is no CGT grandfathering by acquisition date.
Assets acquired before CGT existed are in scope of the reset — and they are the holdings least likely to have cost-base records at all, because for forty years there was no reason to keep them.
Market value at the reset date is the statutory default. The Act contemplates an apportionment election, but the legislative instrument that would define it is not yet registered — consultation closed 21 August 2026. Until it registers, nobody can honestly show you a worked example under it.
One 2026 date is doing two different jobs
Commentary keeps attaching 7:30pm, 12 May 2026 to capital gains. That timestamp belongs to the negative-gearing changes. For CGT there is no acquisition-date line to stand behind: the reset reaches every in-scope asset held at 1 July 2027 through the deemed disposal, bought last decade or last month. Planning built on “my asset is grandfathered” is planning built on the wrong provision.
Why records decide how it lands
A deemed disposal means every holder faces a calculation anchored to the same date. The inputs to that calculation are not opinions — they are records, and the reform makes three kinds of them count:
Contract, settlement statement, incidental costs. Under indexation these stop being history and become inputs.
Capital works with their dates and invoices are cost-base elements. An improvement you cannot evidence is arithmetic you cannot claim.
Whatever basis ultimately applies to your holding, the state of the asset at the reset date is a fact about one moment in time. Evidence captured and independently timestamped when it is true outweighs evidence assembled years later from memory.
None of this requires guessing what the final rules will say. Whatever the unregistered instrument turns out to permit, it will be applied to evidence — and the evidence window for “what was true at the date” closes at the date.
Where the worked examples are
Nowhere honest, yet. The apportionment method is an election whose legislative instrument has not been registered, so a worked example published today is arithmetic against rules that do not exist. This page will keep showing none until that changes. Market value at the reset date is the statutory default in the meantime — and a defensible market value is a valuer's work, not a website's.
AssetDNA keeps a continuous, hash-chained record of a building: documents bound in by SHA-256 fingerprint, history anchored with independent RFC 3161 timestamps, verifiable offline by anyone you hand the export to — without an account, and without AssetDNA existing. If the reset matters to your holdings, that is the shape of record it rewards: built between deals, timestamped when things were true.
AssetDNA does not value your property, does not estimate anyone's tax, and does not tell you what to do. Sealing an owner's own optimistic number would manufacture permanent evidence against them — so the product refuses to be that, by design.