Leading global accountancy bodies are examining the practical implications of estimates and forward-looking information in sustainability assurance assignments
Sustainability assurance professionals are entering
a pivotal new phase in 2026, with a groundbreaking global standard for
assuring climate, social and governance information for
investors now coming into force.
As organisations increasingly rely on targets,
transition plans and forward-looking disclosures to
inform investors and other stakeholders, assurance over this information has
become both more important and more complex.
To support the profession through this major
shift, two leading global accountancy bodies have published
a report to assist practitioners’ professional judgement when dealing
with estimates and forward-looking information in sustainability
assurance engagements.
Estimates and forward-looking information are central to sustainability reporting. Targets, transition plans, and projections now play a key role in informing decisions by investors and other stakeholders. At the same time, such information is inherently uncertain and dependent on professional judgement, assumptions and future events that may not be within an organisation’s control.
As sustainability reporting continues to evolve, so too does the need for credible, decision-useful assurance over this information. The introduction of ISSA 5000 General Requirements for Sustainability Assurance Engagements provides a global framework for assurance over sustainability information, including estimates and forward-looking information.
Applying this framework effectively requires careful professional judgement, particularly where evidence is forward-looking and outcomes cannot be verified at the reporting date.
A case study: Demystifying
the assurance of estimates and forward-looking information in accordance with
ISSA 5000
produced by ACCA (the Association
of Chartered Certified Accountants) and CA ANZ (Chartered Accountants
Australia and New Zealand) supports the application of that professional
judgement in practice. It focuses on how assurance practitioners can respond to
this inherent uncertainty in estimates and forward-looking information when
performing engagements in accordance with ISSA 5000.
Antonis Diolas, Head of Audit and Assurance, Policy
& Insights, ACCA said: ‘This report
reinforces a critical distinction: assurance over such information relates to its
preparation and disclosure, not to whether future outcomes will ultimately be
achieved. Our work in this area underlines how the role of the accountant is being
redefined.’
Amir Ghandar, Reporting and Assurance
Leader, CA ANZ, said: ‘By bringing the requirements on estimates and
forward-looking information together and grounding them in a practical case
study,
this report provides much needed
guidance for assurance practitioners. Most importantly, it reinforces
the central role of professional judgement in delivering assurance
that users can actually rely on.’
The report
takes the form of a case study focussing on how practitioners respond to
identified risks, perform procedures appropriate to the level of assurance,
whether limited or reasonable, and evaluate evidence and uncertainty.
It also highlights
how issues identified in relation to the underlying estimates and
forward-looking information may affect the overall assurance conclusion.
Read the report.