AASB S1 and AASB S2

How the Australian standards fit together and the implementation aspects that matter in practice.

What is mandatory and what is voluntary

The AASB states that the Australian Sustainability Reporting Standards consist of two standards: AASB S1 General Requirements for Disclosure of Sustainability-related Financial Information and AASB S2 Climate-related Disclosures.

AASB S1 is voluntary. AASB S2 is mandatory for entities that fall within the Corporations Act sustainability reporting regime. That distinction matters operationally because many organisations will build to the wider AASB S1 architecture while only climate reporting is compulsory today.

How the standards relate to IFRS S1 and IFRS S2

AASB FAQ guidance says both standards are closely aligned to the ISSB baseline. AASB S1 follows the structure of IFRS S1, and AASB S2 follows the structure of IFRS S2, with modifications for the Australian legal and institutional environment.

For teams reporting across jurisdictions, that means the Australian standards can often sit within a broader ISSB-aligned reporting design rather than requiring a wholly separate conceptual model.

Why AASB S1 still matters even though it is voluntary

AASB S1 sets the general sustainability disclosure architecture that many organisations will use as the design logic for governance, materiality, and connected reporting across topics.

The AASB also explains that Appendix D in AASB S2 pulls across general requirements from AASB S1 so that climate reporting can function as a standalone mandatory standard. In practice, teams should understand both standards together, not treat AASB S2 as a disconnected checklist.

Core disclosure aspects in AASB S2

AASB S2 requires information on governance, strategy, risk management, and metrics and targets, including climate-related risks and opportunities, scenario analysis, and Scope 1, Scope 2 and Scope 3 emissions.

AASB technical material also highlights related concepts that affect implementation: material information, fair presentation, reporting entity alignment with the financial statements, value-chain information, and connected information across the disclosures and financial statements.

Materiality, fair presentation, and evidence quality

The AASB explains that AASB S2 uses a materiality concept aligned to Australian Accounting Standards and expects fair presentation of all climate-related risks and opportunities that could reasonably be expected to affect the entity’s prospects.

The technical FAQs also emphasise use of reasonable and supportable information available at the reporting date without undue cost or effort. That is not a licence for weak evidence; it is a proportionality principle that still requires disciplined assumptions, transparent methods, and freedom from material error.

What reporting teams need in practice

The reporting burden is not only narrative drafting. Teams need traceable data lineage, reviewable assumptions, calculation support, management sign-off, and version-controlled evidence for each disclosure area.

A workable operating model therefore connects accounting, sustainability, risk, operations, treasury, and legal rather than treating AASB S1 and AASB S2 as isolated ESG questionnaires.

Additional resources

Official sources

For detailed and current requirements, use the Corporations Act, ASIC sustainability reporting guidance, AASB materials, and other relevant Australian regulators.