Ask most businesses approaching mandatory climate disclosure for the first time what the deliverable is, and they'll describe a document — a Sustainability Report, sitting alongside the Annual Report, lodged with ASIC. That's true as far as it goes. But treating the report as the objective, rather than the final output of a longer process, is the single most common reason companies find themselves scrambling in the weeks before lodgement.
The report is where a defensible reporting process becomes visible. It is not where that process begins.
What actually has to exist before a report can be written
Before a single disclosure can be drafted, several things need to be true. The required data — emissions figures, governance arrangements, risk assessments, forward-looking scenario outcomes — needs to have been identified, collected from the right sources, and organised in a form that supports the disclosure being made. The methodology behind any calculation needs to be documented, not just applied. Assumptions and judgements need to be understood and, where they're contestable, tested. And the evidence supporting all of it needs to exist as a contemporaneous record — created at the time the underlying activity happened, not reconstructed afterwards to fit the narrative of the report.
None of that is report-writing. It's the infrastructure the report writing depends on. Skip it, or leave it until late, and the report-writing stage becomes an exercise in trying to make thin evidence look complete — which is precisely the kind of gap an auditor is trained to find.
Where judgement does the real work
A structured process helps enormously with the mechanical parts of this — identifying what information is required, where it sits, and applying a consistent methodology to calculate and model it. But climate-related financial reporting is not a purely mechanical exercise, and pretending otherwise creates its own risk.
Two things in particular resist automation. The first is testing: taking a calculated result and asking whether it's actually consistent with what's known about the business, rather than simply accepting whatever the model produces. An emissions figure that looks reasonable in isolation can be obviously wrong once you know something about the underlying operations — a discrepancy that a person familiar with the business will catch and a spreadsheet will not.
The second is resolution: working through outstanding questions and judgement calls with management until there is genuine agreement on what the disclosure should say, not just a number that came out of a calculation. Climate disclosure involves real judgement — about materiality, about scope boundaries, about how to treat genuinely uncertain forward-looking assumptions. That judgement has to be made by people who understand both the business and the reporting requirement, and it has to be made deliberately, not defaulted into by whichever number happened to come out of the process first.
A reporting process built to support this kind of judgement — rather than replace it with the appearance of precision — produces a materially more defensible outcome than one that treats the entire exercise as a data pipeline with a report at the end of it.
Bringing the auditor in early, not at the end
The most avoidable failure mode in first-time climate reporting is discovering, during the assurance engagement, that the methodology the auditor is being asked to assure is different from the methodology they would have recommended if consulted earlier. Limited assurance is required from an entity's first reporting period under AASB S2, over Scope 1 and 2 emissions and governance disclosures. That means the assurance conversation isn't a late-stage formality — it's a design input.
Scoping the assurance engagement precisely before it begins — setting out exactly what is, and is not, covered, and providing the auditor with a complete package of contemporaneous evidence rather than a document assembled after the fact — does two things. It reduces the time (and therefore cost) the assurance engagement takes. And it removes the single biggest source of late surprises: an auditor encountering, at the eleventh hour, a methodology or evidence gap that could have been identified and addressed months earlier.
Your auditor shouldn't encounter your methodology for the first time at year end.
The report as evidence, not as the work
None of this is an argument against the report itself — it's the statutory deliverable, and it matters. But a report produced by a rigorous, well-documented process reads differently to an experienced reviewer than one produced under deadline pressure with the underlying work backfilled to match. The report is the visible evidence of the process. It is not, and was never meant to be, the process itself.
Businesses approaching their first mandatory climate disclosure get the best outcome — and the least stressful year-end — when they treat the months before the report as the real work, and the report itself as what a properly-run process naturally produces at the end of it.
This article discusses what needs to exist before a climate-related sustainability report can be prepared and does not constitute legal, accounting or assurance advice. Entities should confirm their specific reporting group and obligations with appropriately qualified advisers. Regulatory basis last reviewed August 2026.