General information, not tax advice. Sources: budget.gov.au, ATO and Parliament material — confirm the current position with a registered tax professional.
The 1 July 2027 CGT deadline: why 30 June 2027 matters#
The 1 July 2027 CGT cost base reset is now law — the Treasury Laws Amendment (Tax Reform No. 1) Act 2026 (Act No. 49 of 2026) received royal assent on 26 June 2026. The date to plan around is 30 June 2027: the last day your gains sit under the old rules (including the 50% discount, where it applied). Property you still hold on that day is treated as sold just before 1 July 2027 — at its market value at the end of 30 June 2027 — and reacquired on 1 July 2027 for that amount, which becomes the new cost base for every future gain.
So the real “CGT valuation deadline” isn’t a form to lodge — it’s having defensible evidence of your 1 July 2027 market value before the trail goes cold. The report itself can only be finalised once 1 July 2027 has passed, which is exactly why the smart move is to prepare now: organise records, choose a pathway, and reserve delivery. There’s no cost or commitment to getting ready early.
The dates that matter#
12 May 2026 — Budget night. The Federal Budget announces the reform: the 50% CGT discount for individuals, trusts and partnerships to be replaced with CPI indexation of the cost base plus a minimum 30% tax on net capital gains, effective from 1 July 2027.
26 June 2026 — Now law. the Treasury Laws Amendment (Tax Reform No. 1) Act 2026 (Act No. 49 of 2026) receives royal assent, converting the announcement into law and confirming the transition mechanics.
Now until 30 June 2027 — the preparation window. Owners and advisers can use this window to confirm who is affected, organise cost base records, and plan valuation evidence. The readiness checklist takes about two minutes.
30 June 2027 — deemed disposal. In-scope assets held on this day are treated as sold just before 1 July 2027 under the transition rules. Gains up to this point keep the old treatment (including the 50% discount, where it applied).
1 July 2027 — deemed reacquisition at market value. The same assets are treated as reacquired on this date, at their market value just before it (s 112-155(3)(a)) — so the valuation date is the end of 30 June 2027, not 1 July. This is the cost base reset, and the single date the whole portfolio of evidence hangs on. Pre-1985 property receives its deemed cost base the same way.
From July 2027 — valuations can be finalised. A market value “as at 1 July 2027” can only be completed once the date has passed, using sales evidence from around it. Contemporaneous valuations (prepared close to the date) are the cleanest evidence; retrospective valuations remain possible later at growing difficulty and cost.
Years later — when you sell. The gain is split: pre-reset growth under the old rules, post-reset growth under indexation and the new rates — calculated from the 1 July 2027 market value. Whoever holds good evidence of that value has the easy conversation.
What “as at” really means for timing#
You cannot buy a finished 1 July 2027 valuation in 2026 — no one can know the value of a date that hasn’t happened. What owners can do beforehand is prepare: organise records, choose a pathway, and (with some providers) reserve delivery. See the valuation pathways comparison for how the options differ.