How is AASB S2 assurance phased in?

AASB S2 assurance is phased in under ASSA 5010. In the first year the auditor reviews governance, climate-related risks and opportunities, and Scope 1 and Scope 2 emissions. In the second and third years all disclosures are reviewed. From the fourth year all disclosures are audited, which reaches every group by 1 July 2030.

AASB S2 Assurance: How Review And Audit Are Phased In

AASB S2 assurance is set by the Auditing and Assurance Standards Board (AUASB), not the AASB. ASSA 5000 sets the general requirements for sustainability assurance engagements, and ASSA 5010 sets the timeline for what the auditor must review or audit in a sustainability report prepared under the Corporations Act. A review gives limited assurance and an audit gives reasonable assurance.

Key points

Assurance is set by the AUASB through ASSA 5000 and ASSA 5010
First year: review of governance, risks and opportunities, and Scope 1 and Scope 2 emissions
Second and third years: review of all disclosures
Fourth year onwards: audit of all disclosures
Audit starts from 1 July 2028 for Group 1, 1 July 2029 for Group 2 and 1 July 2030 for Group 3

What is assured in each year

Reporting year	Level	Disclosures covered
First year	Review	Governance (paragraph 6), climate-related risks and opportunities (paragraphs 9(a), 10(a) and 10(b)), Scope 1 and Scope 2 emissions (paragraph 29(a)(i)(1) to (2) and 29(a)(ii) to (v)), and any statement that there are no material climate-related risks or opportunities
Second and third years	Review	All disclosures in the sustainability report
Fourth year onwards	Audit	All disclosures in the sustainability report

What the first-year review leaves out

The first-year review does not cover the effects of climate-related risks and opportunities on the business model, strategy and financial statements, any transition plan, climate resilience and scenario analysis, risk management processes, Scope 3 emissions, the other cross-industry metrics or targets. These are all reviewed from the second year.

When the fourth year starts for each group

Group	First year (financial years beginning)	Audit of all disclosures from years beginning
Group 1	1 January 2025 to 30 June 2026	1 July 2028
Group 2	1 July 2026 to 30 June 2027	1 July 2029
Group 3	1 July 2027 to 30 June 2028	1 July 2030

The auditor may review or audit more than the minimum. Comparative information that was reviewed in the previous year does not need to be audited in the current year. ASSA 5010 was issued in January 2025 and amended by ASSA 2025-10 in December 2025.

Why it matters for asset-intensive operations

Scope 1 and Scope 2 emissions are reviewed from the first year, so the facility data, emission factors, methods and controls behind them need an audit trail from day one. Moving from review to audit means the auditor tests those controls and source records in more depth, so a process built on spreadsheets and email should be replaced before the fourth year.

References & sources

Primary regulatory documents and authoritative references underpinning this answer.