Spotlight on Sustainability: A Guide to Australia’s New Sustainability Assurance Standard

AUTHOR

Boyce

DATE Published

October 28, 2025

Sustainability Assurance Standards: What You Need to Know (and How Boyce Can Help)

On January 28, 2025, the Australian Auditing and Assurance Standards Board (AUASB) approved a new standard: ASSA 5000 – General Requirements for Sustainability Assurance Engagements.

This is a big step forward. It means sustainability reports must now meet strict assurance standards. These reports need to be credible, consistent, and aligned with global expectations, including the International Standard on Sustainability Assurance (ISSA 5000).

What Does This Mean for Your Business?

Sustainability reporting is no longer just about sharing information. Now, businesses must prove their data is accurate and trustworthy. This gives confidence to investors, regulators, and stakeholders.

What Is ASSA 5000?

ASSA 5000 sets out how to verify sustainability reports. It applies to all sustainability topics and frameworks. Both accountants and other assurance professionals can use it.

When Does It Start?

The standard applies to reports for periods starting on or after January 1, 2025. Assurance will be introduced in phases, starting with limited assurance and moving to reasonable assurance over time.

What Does “Assurance Ready” Mean?

Being “assurance ready” means your business is prepared to meet the new requirements. Here’s what that looks like:

Disclosure: Share all required information under the Australian Sustainability Reporting Standards (ASRS).
Limited Assurance: A moderate level of confidence. This involves high-level reviews and analysis.
Reasonable Assurance: A high level of confidence. This requires detailed evidence and in-depth testing.

Each step demands more effort and stronger internal systems.

Why It Matters

Stay Compliant: Meet new legal and regulatory standards.
Build Trust: Show stakeholders your data is reliable.
Stand Out: Prove your commitment to sustainability and gain a competitive edge.

What Should You Do Now?

Check Your Readiness: Review your current sustainability reporting. Are there gaps?
Plan Ahead: Start preparing for limited assurance now. It’s coming soon.
Partner with Experts: Working with assurance professionals early helps avoid last-minute stress.

How Boyce Can Help

At Boyce, we’re here to guide you through every step of the process. We help businesses:

Run gap assessments against ASSA 5000
Build internal skills and implementation plans
Create assurance-ready climate reports
Work with assurance providers to meet compliance

We make sure your sustainability reporting is not just compliant—but also strategic and future-ready.

table describing auditing and assurance standards board's phased approach

Notes*Group 1 entities with years commencing 1 January to 30 June will be subject to the Year 1 provisions twice (e.g. years commencing 1/1/25 and 1/1/26). Reporting of Scope 3 emissions is required for years commencing 1/1/26 to 30/6/26 for these Group 1 entities.**Years commencing from 1/7/30 to 30/6/31 for Group 3 entities. From that time reasonable assurance is required by the Act for all mandatory climate disclosures. *** The phasing for assurance on statements that there are no material climate-related risks and opportunities would be the same as for ‘Strategy – Risks and Opportunities’. **** Only subparagraphs 9(a), 10(a) and 10(b) of AASB S2.