案例研究：根据ISSA 5000揭开估计和前瞻性信息保证的神秘面纱（英）2026

About Chartered AccountantsAustralia and New Zealand. About ACCA. We are ACCA (the Association of Chartered Certified Accountants),the only truly global professional accountancy body. Chartered Accountants Australia and New Zealand (CA ANZ) represents morethan 140,000 financial professionals, supporting them to build value andmake a difference to the businesses, organisations and communities in whichthey work and live. Since we were founded in 1904, we’ve been breaking down barriersto the accountancy profession. Today we proudly support a diversecommunity of over257,900members and530,100future membersin180countries. Around the world, Chartered Accountants are known for their integrity, financialskills, adaptability and the rigour of their professional education and training. We’reredefining accountancy.Our cutting-edge qualifications,continuouslearning and insights are respected and valued byemployers in every sector. They equip individuals with the businessand finance expertise and ethical judgement to lead and drivesustainable value in organisations and economies worldwide. CA ANZ promotes the Chartered Accountant (CA) designation and high ethicalstandards, delivers world-class services and life-long education to members andadvocates for the public good. We protect the reputation of the designation byensuring members continue to comply with a code of ethics, backed by a robustdiscipline process. We also monitor Chartered Accountants who offer servicesdirectly to the public. Guided by our purpose and values, we’re leading the accountancyprofession for a changed world. Partnering with policymakers, standardsetters, the donor community, educators and other accountancybodies, we’re strengthening and building a profession that focuses onpeople, planet and prosperity to create value for all. Our flagship CA Program, the pathway to becoming a Chartered Accountant,combines rigorous education with practical experience. Ongoing professionaldevelopment helps members shape business decisions and remain relevant ina changing world. Find out more ataccaglobal.com We actively engage with governments, regulators and standard-setters on behalfof members and the profession to advocate in the public interest. Our thoughtleadership promotes prosperity in Australia and New Zealand. Find out more atcharteredaccountantsanz.com About this report. Foreword. Using a practical case study, this report providesguidanceon how to apply the ISSA 5000requirementswith respect to estimates andforward-looking information under both limited andreasonable assurance in a Sustainability AssuranceEngagement. Additionally, the report explains whyestimates and forward-looking information presentparticular challenges for sustainability assuranceengagements. It explores the nature of uncertainty,evidence limitations and the expectation gap thatpractitioners must navigate when applying ISSA5000. The report concludes with some practicalconsiderationsand recommendations that ourmembers and stakeholders should take into accountwhen applying the ISSA 5000 requirements relatingto estimates and forward-looking information. Estimates and forward-looking information are central to sustainability reporting.Targets, transition plans and projections now play a key role in informing decisionsby investors and other stakeholders. At the same time, such information is inherentlyuncertain and dependent on professional judgement, assumptions and future eventsthat may not be within an organisation’s control. As sustainability reporting continues to evolve, so too does the need for credible, decision-useful assurance overthis information. The introduction of ISSA 5000General Requirements for Sustainability Assurance Engagements(hereafter ‘the Standard’) provides a global framework for assurance over sustainability information, includingestimates and forward-looking information. Applying this framework effectively requires careful professionaljudgement, particularly where evidence is forward-looking and outcomes cannot be verified at the reporting date. Claire LindridgeDirector – Policy &Insights, ACCA This report has been developed to support the application of that professional judgement in practice. It focuseson how assurance practitioners can respond to this inherent uncertainty in estimates and forward-lookinginformation when performing engagements in accordance with ISSA 5000. In doing so, it reinforces a criticaldistinction: assurance over such information relates to its preparation and disclosure, not to whether futureoutcomes will ultimately be achieved. This report forms the second part of a series exploring the application of ISSA 5000 in practice, following an earlierreport focusing on materiality(ACCA and CA ANZ 2025). By bringing together key ISSA 5000 requirements andpractical illustrations, it aims to promote a consistent and proportionate approach to assurance in this evolvingarea. It is intended to assist assurance practitioners, pr