Assurance – Limited and Reasonable

Limited and Reasonable Assurance services provide organisations with independent, third-party verification of their non-financial information, strengthening the credibility and reliability of sustainability disclosures. At SESG, we deliver both levels of assurance using globally recognised standards, helping you demonstrate transparency and accountability to investors, regulators, and other stakeholders.

Understanding Limited and Reasonable Assurance

Limited and reasonable assurance represent two distinct levels of confidence that an independent assurance provider can offer over reported information. Limited assurance involves analytical procedures, enquiries, and plausibility checks that provide a moderate level of confidence. The assurance provider concludes whether anything has come to their attention that causes them to believe the information is materially misstated. Reasonable assurance involves more extensive procedures, including detailed testing, verification of underlying data, and evaluation of internal controls, resulting in a higher level of confidence. The assurance provider expresses a positive opinion on whether the information is fairly stated in all material respects. Both levels of limited and reasonable assurance serve important roles depending on the maturity of your reporting systems, regulatory requirements, and stakeholder expectations.

Our Approach to Limited and Reasonable Assurance

SESG provides limited and reasonable assurance engagements conducted in accordance with the International Auditing and Assurance Standards Board (IAASB) standards, including ISAE 3000 (Revised) for assurance engagements other than audits or reviews of historical financial information, and ISAE 3410 for greenhouse gas statements. We also work with Australian standards ASAE 3000 and ASAE 3410, as well as AccountAbility’s AA1000AS v3 for sustainability assurance. Our accredited in-house auditors bring deep technical knowledge across these frameworks, ensuring that every engagement meets the highest standards of professional rigour and independence. Our process begins with understanding the scope and subject matter of the assurance engagement, whether that covers a full sustainability report, specific ESG metrics, greenhouse gas emissions data, or regulatory disclosures. We then design and execute procedures appropriate to the level of assurance being provided, documenting findings and communicating results through a formal assurance statement that can be published alongside your report.

When to Choose Limited or Reasonable Assurance

The choice between limited and reasonable assurance depends on several factors, including the maturity of your data collection and reporting processes, stakeholder and regulatory expectations, and the strategic importance of the information being assured. Many organisations begin with limited assurance as they establish their sustainability reporting practices and build confidence in their data systems. As reporting processes mature and stakeholder expectations increase, organisations often transition to reasonable assurance over key metrics or their entire sustainability report. SESG helps you navigate this journey by assessing your readiness for each level of assurance and providing practical recommendations for strengthening your reporting infrastructure. Our assurance framework development services complement our limited and reasonable assurance engagements, ensuring that your organisation has the systems, controls, and governance structures needed to support increasingly rigorous levels of verification over time.

Getting Started with Limited and Reasonable Assurance

Whether you require limited assurance over a specific set of sustainability metrics or reasonable assurance across your entire ESG disclosure, SESG provides a professional, efficient, and value-adding service. Our team works collaboratively with your reporting and sustainability functions to minimise disruption while delivering assurance outcomes that strengthen stakeholder trust and support regulatory compliance. Contact us to discuss how limited and reasonable assurance can enhance the credibility of your sustainability reporting and position your organisation as a trusted leader in transparent corporate disclosure. We tailor every engagement to your specific reporting requirements, organisational context, and assurance objectives.