Picture a CFO in Melbourne closing the books for a 30 June year-end. The audit is on track, the tax provision is signed off, and then a note arrives from the board asking a simple question: is our first ASRS sustainability report ready to lodge with ASIC alongside the annual report? For Group 1 entities, that question is no longer theoretical. Australia’s mandatory climate disclosure regime is live, the first Group 1 filings with December 2025 year-ends have been lodged, and Groups 2 and 3 are next.
This blog walks through what ASRS is, how AASB S1 and AASB S2 differ, which entities fall into each reporting group, what must be disclosed, and where preparers are running into trouble in 2026.
ASRS at a Glance
The Australian Sustainability Reporting Standards (ASRS) are Australia’s local implementation of the ISSB’s global sustainability disclosure standards. The AASB issued the standards in September 2024, and the legal obligation to report was inserted into Chapter 2M of the Corporations Act 2001 via the Treasury Laws Amendment (Financial Market Infrastructure and Other Measures) Act 2024. AASB-specific paragraphs are layered on top of the ISSB’s IFRS S1 and S2 baseline, with the regime commencing for the largest entities on 1 January 2025 and phasing down to smaller companies through 2027, as summarised in Brightest’s 2026 guide to Australian sustainability reporting requirements.
Two regulators anchor the regime in practice. ASIC supervises reporting entities under Regulatory Guide 280, published in March 2025, while the AUASB governs the phased assurance pathway.
AASB S1 vs AASB S2: What Sits Where
The two standards are frequently bundled in commentary, but only one carries a legal reporting duty today.
AASB S2 is the mandatory climate-related financial disclosure standard. It is where the compliance obligation lives, and it is what an assurer will be engaged to sign off on.
AASB S1 covers general sustainability-related disclosures beyond climate and remains voluntary. Some Group 1 filers align with S1 anyway to strengthen investor communication, but the modified liability relief attached to certain S2 disclosures does not extend to any voluntary S1 content.
For most preparers, the practical implication is straightforward: AASB S2 is the priority.
Who Reports When: The Three-Group Rollout
ASRS phases in across three cohorts, and your group determines the deadline. The classification tests use consolidated revenue, gross assets, and headcount, applied on a two-of-three basis:
- Group 1: consolidated revenue of A$500 million or more, gross assets of A$1 billion or more, or 500 or more employees. Reporting begins for financial years starting on or after 1 January 2025.
- Group 2: consolidated revenue of A$200 million or more, gross assets of A$500 million or more, or 250 or more employees. Also captures asset owners with A$5 billion or more under management. Reporting begins for financial years starting on or after 1 July 2026.
- Group 3: consolidated revenue of A$50 million or more, gross assets of A$25 million or more, or 100 or more employees. Reporting begins for financial years starting on or after 1 July 2027.
Two additional entry points sit outside the size tests. NGER reporters are captured by their emissions profile regardless of financial size, and foreign-parented groups must assess their Australian consolidated entity separately, since a global consolidated report will not satisfy the local lodgement duty.
What You Actually Have to Disclose
AASB S2 is structurally lean but operationally demanding. A sustainability report is built around four TCFD-aligned pillars:
- Governance: which board members own climate risk, how they are informed, and how management supports the board.
- Strategy: the climate-related risks and opportunities that could reasonably affect prospects, cash flows, or cost of capital across short-term, medium-term, and long-term horizons, backed by scenario analysis covering at least one well-below 2 degrees Celsius scenario and one higher warming scenario.
- Risk management: how climate risks are identified, assessed, and integrated into enterprise risk processes.
- Metrics and targets: Scope 1, Scope 2, and, from the second reporting year, material Scope 3 emissions, plus any climate-related targets and links to executive remuneration.
Greenhouse gas measurement follows the GHG Protocol, with an Australian carve-out permitting NGER methods for parts of an entity already reporting under that scheme. The December 2025 AASB S2025-1 amendments confirmed the part-by-part application of that carve-out, as Terrascope’s 2026 guide to Australia’s climate disclosure rules explains.
The 2026 Changes You Cannot Ignore
Two developments have reshaped the practical landscape this year, and they are often confused with each other.
The first is the modified liability window. Late in 2025, Treasury broadened the modified liability protections attached to certain AASB S2 disclosures, giving Scope 3, scenario analysis, and transition plan content limited protection from private legal action for a fixed period. The window does not cover voluntary AASB S1 content, and it does not blunt ASIC or criminal enforcement powers, a point highlighted in KPMG Australia’s sustainability reporting briefing.
The second is threshold reform. The May 2026 Federal Budget proposed lifting the large proprietary company thresholds, which would take a portion of the mid-market out of the eventual Group 3 population. This is not a delay of the regime itself. Group 1 is already filing, Group 2 still commences in July 2026, and Group 3 remains on track for July 2027, a distinction underlined in Trace’s 2026 ASRS threshold analysis. Boards should not read the Budget as an extension.
Where Australian Businesses Are Getting Stuck
Field patterns from the first Group 1 cycle look similar across manufacturing, real estate, and retail:
- Fragmented emissions data spread across finance, operations, procurement, and facilities systems, with no single reconciled source of truth.
- Scope 3 categories that cannot be defended to an assurer because supplier data is incomplete or inconsistently mapped.
- Governance disclosures that read as aspirational rather than being evidenced by board minutes.
- Scenario analysis outputs that do not translate cleanly into the linked financial statement line items.
- Manual spreadsheet workflows that break under phased assurance requirements.
These are data infrastructure problems more than they are policy problems. Assurance readiness stands or falls on whether the numbers can be traced from source system to disclosure line with a complete audit trail.
Building a Reporting Function That Holds Up to Assurance
A defensible ASRS program tends to share four traits: a single governed data layer for financial, operational, and emissions data; framework-aligned calculation logic that maps cleanly to AASB S2; a controls environment that records approvals and changes; and disclosure outputs that can be regenerated on demand rather than reconstructed each year.
This is the space where 4Seer Technologies works with reporting teams. Its GRI-certified reporting platform 4Scope supports six global frameworks, including GRI, CDP, TCFD, CSRD, ESRS, and BRSR, giving Australian entities a route to align AASB S2 disclosures with parallel obligations across their global footprint. The 4Vue data platform integrates 30-plus enterprise data sources so that Scope 1, 2, and 3 inputs, financial ledgers, and operational metrics feed the same reconciled model, backed by proven delivery across ten countries.
For CFOs, CSOs, and audit committee chairs, the practical next step is a readiness diagnostic against your reporting group, a data source inventory against AASB S2 requirements, and a phased build toward the assurance timetable. The regime rewards early operational work far more than late policy work.
Frequently Asked Questions
Is AASB S1 Mandatory in Australia in 2026?
No. AASB S1 remains voluntary for Australian entities in 2026. Only AASB S2, the climate-related financial disclosures standard, carries a legal reporting obligation under Chapter 2M of the Corporations Act. Many Group 1 entities still choose to align voluntarily with S1 to strengthen investor communication, but there is no lodgement duty, and the modified liability relief that applies to certain S2 disclosures does not extend to voluntary S1 content.
When Does My Company Need to Start ASRS Reporting?
Your start date depends on your reporting group. Group 1 entities began reporting for financial years commencing on or after 1 January 2025. Group 2 entities commence for financial years starting on or after 1 July 2026, and Group 3 entities from 1 July 2027. Test your consolidated revenue, gross assets, and employee numbers against the two-of-three threshold test, and check whether the NGER reporter or asset owner tests capture you separately.
Do I Need to Report Scope 3 Emissions Under AASB S2?
Yes, but not in your first reporting year. Scope 3 becomes mandatory from your second AASB S2 reporting period for material value chain categories. In year one, you must still identify Scope 3 as part of your climate risk assessment. A limited liability window applies to Scope 3, scenario analysis, and transition plan disclosures for a fixed period, protecting good-faith preparers from certain private actions during the transition.
What Is the Difference Between ASRS and AASB S2?
The terms are often used interchangeably, but they are not identical. ASRS refers to the Australian Sustainability Reporting Standards as a body of work, while AASB S2 is the specific mandatory climate disclosure standard within that body, issued by the Australian Accounting Standards Board. AASB S1 sits alongside AASB S2 as the voluntary general sustainability standard. Regulators, auditors, and preparers use both labels in market commentary and internal reporting documents.
What Are the Penalties for Non-Compliance With Mandatory Climate Reporting?
Directors of reporting entities can face personal liability for misleading or deceptive sustainability statements, in line with existing financial reporting duties under the Corporations Act. Corporate penalties for false or misleading climate disclosures can reach up to A$15 million or 10 percent of annual turnover, and ASIC retains full enforcement powers even during the modified liability window. Late lodgement, incomplete Scope disclosures, or unsupported scenario analysis all carry regulatory and reputational exposure.
