CGT Reform from 1 July 2027: Why Simple Examples Can Mislead

Short answer

A reliable post-1 July 2027 CGT estimate cannot always be produced from only the original purchase price, sale price and total holding period.

For assets already held on 30 June 2027, the Treasury Laws Amendment (Tax Reform No. 1) Act 2026 contains deemed-sale and reacquisition rules. The transition amount can be based on market value just before 1 July 2027 or an available statutory apportionment method. A pre-July gain can be deferred until the eventual sale, while indexation applies only under the post-July rules.

Why the earlier examples were withdrawn

Earlier examples on this page indexed the original cost base across the full ownership period and applied a 30% floor to the nominal gain. That was too simple and could materially misstate tax.

The enacted calculation can also depend on:

• whether the asset was held on 30 June 2027,
• the market value or permitted apportionment at transition,
• the part of the gain relating to periods before and after 1 July 2027,
• capital losses and quarantined residential property amounts,
• whether the asset is a qualifying new residential dwelling,
• residency, trust and beneficiary rules,
• main-residence and small-business concessions,
• the taxpayer's broader income and minimum-tax calculation.

When the simplified calculator can be used

The CGT Reform Comparison Calculator now states a narrow assumption: an Australian resident individual acquires the asset on or after 1 July 2027 and no special exemption, new-build choice, loss or trust treatment applies.

It is a comparison model, not a tax-return calculator.

Sources

• Treasury Laws Amendment (Tax Reform No. 1) Act 2026, especially Schedules 1 and 2, checked 10 July 2026.

General information disclaimer

This page is general information only and is not tax advice. Obtain a valuation and registered tax advice before relying on any transition calculation.