01 Tax & selling Reviewed 30 August 2026
CGT cost base
Cost base
The tax-law amount used when working out a capital gain on a CGT asset.
What Cost base means
It can include the purchase amount and eligible acquisition, ownership, improvement and disposal costs, subject to exclusions and adjustments.
Why it matters
Missing eligible records can overstate a gain, while including amounts that must be excluded can understate it.
Current-law note
Timing changes the answer
The cost base has five statutory elements. For relevant CGT events from 1 July 2027, enacted indexation and transition rules can also affect residential-property calculations.
Take the next step
Ask Heyward A definition cannot see your position. Heyward can.
Start with: “Build a cost-base checklist for this property and flag the records still missing.”
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Sources
Primary & official where available- Australian Taxation Office Cost base of assets
- Federal Register of Legislation Treasury Laws Amendment (Tax Reform No. 1) Act 2026
General educational information only. It does not account for your objectives, financial situation, legal position or tax circumstances.