Australia AASB S2: Phase-In Timeline Explained

Australia's mandatory climate disclosure regime is one of the more clearly staged rollouts globally — which makes it easier to plan around, provided you know which group you're in.

The legal foundation

AASB S2 (Climate-related Disclosures) was inserted into the Corporations Act via the Treasury Laws Amendment (Financial Market Infrastructure and Other Measures) Act 2024. It's built on the ISSB's global IFRS S2 standard, with Australia-specific additions — including a requirement to disclose both a "current policies" scenario and an additional scenario aligned with limiting warming to 1.5°C, and to quantify the financial effects of both, not just describe them narratively.

Unlike CSRD's dense multi-standard architecture, AASB S2 is a single, comparatively lean standard sitting inside existing corporate law — but the compliance framework wrapped around it (ASIC oversight, phased assurance, civil penalties for directors) is substantial.

The three groups, and when each starts

Group 1 — the largest entities: consolidated revenue ≥ A$500 million, consolidated assets ≥ A$1 billion, or 500+ employees (meeting at least two of these). Reporting from financial years beginning on or after 1 January 2025. Group 1 is live now — 259 first sustainability reports had been lodged with the regulator as of early May 2026.

Group 2 — mid-large entities: consolidated revenue ≥ A$200 million, consolidated assets ≥ A$500 million, or 250+ employees; this group also includes large asset owners (super funds, registered schemes) with assets under management ≥ A$5 billion. Reporting from financial years beginning on or after 1 July 2026.

Group 3 — smaller large entities: consolidated revenue ≥ A$50 million, consolidated assets ≥ A$25 million, or 100+ employees. Reporting from financial years beginning on or after 1 July 2027. Group 3 entities can claim an exemption, but only with a documented materiality assessment showing no material climate-related risks or opportunities — this is not a blanket opt-out, and the assessment process itself has to be genuine and defensible.

A note for Group 2 companies specifically

If you're a Group 2 entity, your first reporting period is essentially now (mid-2026 onward), and a few Year 1 specifics are worth knowing:

• Scope 3 grace period: you don't need to report Scope 3 emissions in your first year, but you must begin collecting the data immediately — Scope 3 becomes mandatory from your second reporting year.
• No comparative data required in your first report.
• Modified liability: a three-year safe harbour applies to forward-looking statements, including scenario analysis and transition plan commentary — giving some breathing room while methodologies mature.
• Limited assurance applies from Year 1, specifically over Scope 1 and 2 emissions and governance disclosures. Full reasonable assurance across all disclosures phases in by financial years starting on or after 1 July 2030.

Penalties are real and personal

False or misleading climate statements can trigger fines up to A$15 million or 10% of annual turnover (whichever is greater), and directors can be held personally liable — this sits inside the Corporations Act, not a separate lighter-touch sustainability code.

Worth watching

The Group 3 threshold itself isn't fully settled — the May 2026 Federal Budget proposed raising the entry thresholds for Group 3, alongside a consultation on assurance settings and how companies can request supplier information. If you're currently sitting just above the Group 3 line, it's worth keeping an eye on where that threshold actually lands before assuming you're in scope for 2027.