Timeline for assurance over your mandatory sustainability report

This article was originally published October 2024 and last updated May 2025. 

From 1 January 2025, large Australian entities are required by the Corporations Act 2001 to begin mandatory sustainability reporting in accordance with AASB S2 Climate-related Disclosures. These disclosures must be assured in accordance with ASSA 5000 General Requirements for Sustainability Assurance Engagements and ASSA 5010 Timeline for Audits and Reviews of Information in Sustainability Reports under the Corporations Act 2001. ASSA 5010 sets out a staged approach to assurance, transitioning from limited assurance (i.e. review engagements) in the early years to reasonable assurance (i.e. audit engagements) over time.

The assurance timeline is structured across four reporting years, but the progression isn’t always a simple one-year interval. The timing depends on when your organisation’s first mandatory reporting year begins. The table below outlines the phased approach for each group. 

  First year Second year Third year Fourth year Fifth year Sixth year
Group 1 1 Jan 2025 to 30 June 2026 1 July 2026 to 30 June 2027 1 July 2027 to 30 June 2028 1 July 2028 to 30 June 2029 1 July 2029 to 30 June 2030 1 July 2030 to 30 June 2031
Group 2 1 July 2026 to 30 June 2027 1 July 2027 to 30 June 2028 1 July 2028 to 30 June 2029 1 July 2029 to 30 June 2030 1 July 2030 to 30 June 2031 1 July 2031 to 30 June 2032
Group 3 1 July 2027 to 30 June 2028 1 July 2028 to 30 June 2029 1 July 2029 to 30 June 2030 1 July 2030 to 30 June 2031 1 July 2031 to 30 June 2032 1 July 2032 to 30 June 2033
Sustainability disclosures
Governance Limited Limited Limited Reasonable Reasonable Reasonable
Strategy - Risks and opportunities (only subparagraphs 9(a), 10(a) and 10(b) of AASB s2) Limited Limited Limited Reasonable Reasonable Reasonable
Climate resilience / scenario analysis None Limited Limited Reasonable Reasonable Reasonable
Transition plans None Limited Limited Reasonable Reasonable Reasonable
Risk management None Limited Limited Reasonable Reasonable Reasonable
Scope 1 and Scope 2 emissions Limited Limited Limited Reasonable Reasonable Reasonable
Scope 3 emissions N/A (transition exemption defers disclosure to second year) Limited Limited Reasonable Reasonable Reasonable
Climate-related metrics and targets None Limited Limited Reasonable Reasonable Reasonable
If the entity believes it has no material climate risks and no material climate opportunities, it must provide a statement detailing why (s296B(1)(c) and (d)) Limited Limited Limited Reasonable Reasonable Reasonable


ASSA 5010 states that Group 1 entities with years commencing 1 January to 30 June will be subject to the first year assurance provisions twice (e.g. years commencing 1 January 2025 and 1 January 2026). However, the transitional relief outlined in AASB S2 in relation to Scope 3 emissions will only apply to the first year of reporting.

The following table illustrates what this requirement would mean for Group 1 entities with years commencing 1 January 2025 to 30 June 2025, for example, entities with a 31 December 2025 year-end:

  31 December 2025 year-end 31 December 2026 year-end 31 December 2027 year-end
Reporting AASB S2 Limited Assurance Reporting AASB S2 Limited Assurance Reporting AASB S2 Limited Assurance
Governance Yes Yes Yes Yes Yes Yes
Strategy – Risks and Opportunities (only para 9(a), 10(a) & 10(b)) Yes Yes Yes Yes Yes Yes
Climate Resilience Assessments / Scenario Analysis Yes No Yes No Yes Yes
Transition Plans Yes No Yes No Yes Yes
Risk Management Yes No Yes No Yes Yes
Scope 1 and 2 Emissions Yes Yes Yes Yes Yes Yes
Scope 3 Emissions No No Yes No Yes Yes
Climate-related Metrics and Targets Yes No Yes No Yes Yes


In contrast to the above, the following table illustrates what this requirement would mean for Group 1 entities with years commencing on or after 1 July 2025, for example, entities with a 30 June 2026 year-end:
 

  30 June 2026 year-end 30 June 2027 year-end 30 June 2028 year-end
Reporting AASB S2 Limited Assurance Reporting AASB S2 Limited Assurance Reporting AASB S2 Limited Assurance
Governance Yes Yes Yes Yes Yes Yes
Strategy - Risks and Opportunities (only para 9(a), 10(a) & 10(b)) Yes Yes Yes Yes Yes Yes
Climate Resilience Assessments / Scenario Analysis Yes No Yes Yes Yes Yes
Transition Plans Yes No Yes Yes Yes Yes
Risk Management Yes No Yes Yes Yes Yes
Scope 1 and 2 Emissions Yes Yes Yes Yes Yes Yes
Scope 3 Emissions No No Yes Yes Yes Yes
Climate-related Metrics and Targets Yes No Yes Yes Yes Yes

Can we omit information from climate disclosures if no assurance is required?

As illustrated in the above tables, in the first year, no assurance is required for information about climate resilience/scenario analysis, transition plans, risk management, Scope 3 emissions and metrics and targets. Preparers are, therefore, asking whether this information can be omitted from the climate disclosures.

The answer is ‘No’. Other than the one year deferral permitted for disclosures of Scope 3 emissions (AASB S2, paragraph C4(b)), all other information must be included with the climate disclosures for the purposes of the Corporations Act 2001, prepared in accordance with AASB S2.

How BDO can help

Our sustainability assurance experts are here to help you build trust and credibility through transparent and accurate reporting. With limited assurance required for Scopes 1, 2 and 3 emissions from the second year, it’s crucial to start preparing accurate climate disclosures now.

Contact us today.