This week the Auditing and Assurance Standards Board (AUASB) approved the adoption of international standard ISSA 5000 General Requirements for Sustainability Assurance Engagements in Australia.

ISSA 5000 was formally launched by the International Auditing and Assurance Standards Board with implementation guidance on 27 January 2025.

As well as contributing to greater international alignment of assurance over climate and other sustainability information, the new standard will support confidence in information disclosed in the annual reports of Australia’s largest companies from years commencing 1 January 2025.

AUASB standard ASSA 5000 General Requirements for Sustainability Assurance Engagements will apply to sustainability assurance engagements for reporting periods beginning on or after 1 January 2025.

Phasing of assurance for mandatory climate reporting

For mandatory climate reporting under the Corporations Act 2001 (the Act), ASSA 5000 will be subject to the phasing in of limited and reasonable assurance under AUASB standard ASSA 5010 Timeline for Audits and Reviews of Information in Sustainability Reports under the Corporations Act 2001, which the AUASB formally approved yesterday.

There were no changes to the assurance phasing model previously approved at the AUASB’s 16 December 2024 meeting.

Mandatory reporting under the Act commences at different times for each of three groups of entities.

Under the Act, the auditor of an entity’s financial report also provides assurance over the mandatory climate information in an annual report.  The following table shows the phasing in of limited and reasonable assurance over the information required by AASB S2 Climate-related Disclosures for each of the three groups of entities (earlier assurance permitted).