Significant changes are coming to Australia’s Capital Gains Tax (CGT) rules from 1 July 2027, with the current 50% CGT discount set to be replaced by a cost base indexation system for future capital gains.
If you hold investment assets such as property, shares, or business investments, understanding these changes now could have a major impact on your long-term tax planning.

What Is Changing?
Currently, individuals and trusts who hold eligible assets for more than 12 months can generally reduce their capital gain by 50% before tax is applied.
Under the proposed changes, the 50% CGT discount will no longer apply to gains accruing from 1 July 2027 onwards.
Instead, the cost base of an asset will be indexed in line with inflation (CPI), allowing taxpayers to adjust the original purchase price before calculating the taxable gain.
In addition, a minimum 30% tax rate will apply to net capital gains.
This Isn’t a Completely New System
While the announcement has generated significant discussion, Australia has used a similar approach before.
From 1985 to 1999, capital gains were calculated using cost base indexation rather than the 50% discount method. The proposed rules effectively reintroduce that concept for future gains.
Importantly:
- Capital gains accrued before 1 July 2027 will still be eligible for the existing 50% CGT discount.
- Only gains accruing after that date will fall under the new indexed system.
This means the timing of asset ownership and valuation could become increasingly important.
How Could This Affect Investors?
The impact will vary depending on:
- The type of asset
- How long it is held
- Future inflation levels
- The size of the capital gain
Long-held assets with significant growth may face noticeably higher tax outcomes under the new rules compared to the current system.
A Worked Example
Consider an investment asset:
- Purchased for $500,000
- Sold in 2037 for $2,000,000
Under the current 50% discount method, only half of the capital gain would generally be taxable.
Under the proposed indexed approach, the taxable gain could be substantially higher, even after adjusting the cost base for inflation.
In this example, the additional tax payable under the new rules could be approximately $56,000 higher than under the current system.
While every situation is different, the direction of change is clear – investors holding appreciating assets over long periods may see increased tax exposure.
Should You Sell Before 1 July 2027?
There is no universal answer.
For some investors, bringing forward a sale before the rule changes may be beneficial. For others, retaining the asset may still produce the best long-term financial outcome.
Key considerations include:
- Unrealised capital gains
- Expected future growth
- Holding structures
- Personal tax rates
- Retirement and succession planning
- Cash flow and investment objectives
Importantly, tax should not be the sole driver of an investment decision.
Planning Ahead Is Critical
The proposed CGT changes reinforce the importance of proactive tax and investment planning.
Waiting until 2027 to review your position may limit your options and reduce your ability to structure effectively.
Modelling different scenarios now can help you:
- Understand your future tax exposure
- Assess whether restructuring is appropriate
- Evaluate potential sale timing strategies
- Make informed long-term investment decisions
If you hold investment assets and are concerned about how the proposed CGT changes may affect you, seeking professional advice early can help ensure you are prepared well before the new rules commence.









