Glossary›Assurance, audit evidence and working papers›Working papers (climate disclosure)
Glossary term
Cluster A · A1
Tier 1 · differentiator
Working papers (climate disclosure)
Definition
Working papers are the organised file of evidence, calculations and decisions that supports every number and statement in a climate disclosure. For an Australian sustainability report they typically include source documents, the emissions calculation model, the emission factors applied, the judgements made and who approved them. The assurance provider tests the report through these papers.
No governing instrument for the preparer
· ASSA 5000 governs the assurer’s own documentation ·
Practice
On this page
In practice
No standard tells a reporting entity how to keep working papers. That is exactly why they are the thing most first-time reporters have not prepared. The obligation is indirect but absolute: the Corporations Act requires the sustainability report to be assured, ASSA 5000 requires the assurance provider to obtain evidence, and if you cannot produce the evidence the engagement stalls or the conclusion is modified.
A working paper file for a first climate report is usually organised by disclosure, not by data source. Each disclosed figure gets a folder holding the source records, the calculation that turns them into the figure, the factor set with its version, the reconciliation to a finance system total where one exists, and a note explaining any judgement.
The confusion sits in scale. Controllers expect a file the size of a tax schedule. For a mid-sized Group 2 entity, the first-year emissions file is usually larger than the entire statutory accounts working paper file, because emissions data arrives from dozens of unconnected systems that were never designed to be audited.
What the assurer does with it
The assurer does not read your report and then go looking for support. They start from the working papers and work outwards. In practice they ask for the basis of preparation first, then the calculation model, then a sample of source documents behind selected figures. They accept an externally generated source document with a clear line to a report figure. They reject a spreadsheet cell containing a hardcoded number with no formula and no note, an emission factor with no cited version, and any figure whose supporting file has been edited since the report was drafted with no change log. The most common finding in a first-year file is a working paper that supports a number the entity no longer reports, because the model was rerun and the paper was not.
Commonly confused with
The audit file. Working papers in this sense are yours, prepared by or for the reporting entity. The assurance provider keeps its own separate engagement file under ASSA 5000, which you never see.
Sources
1
ASSA 5000 General Requirements for Sustainability Assurance Engagements
AUASB
2
Review status
Review required
Last reviewed
15 September 2026
Editorial pass, unsigned
Reviewer required
Registered company auditor
Next scheduled review
1 July 2027
Part of
Cluster A, Assurance, audit evidence and working papers
47 terms on what an assurance provider tests, what they accept as evidence, and what a preparer has to be able to produce.
Related terms
What the assurer will accept out of the file you hand over
The strongest single item a working paper can reference
The document the assurer reads before anything else in the file
Related questions
What are working papers for a climate report?
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Working papers are the file showing how each reported number was produced: the source document, the activity data taken from it, the emission factor and its published source, the calculation, the judgements made, and who prepared and reviewed it. If someone else cannot rebuild your number from the file, it is not finished.
What will our auditor actually ask for?
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In year one they ask for evidence behind the disclosures that are actually assured: Scope 1 and Scope 2 emissions, your governance disclosures, and the specified strategy paragraphs on climate risks and opportunities. In practice that means source documents, a calculation they can rebuild from those documents, and minutes showing the governance you described actually happened.
How do we prepare for assurance without a sustainability team?
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You need three things and only one has to sit inside your business: someone to retrieve data from your own systems, someone who knows what evidence the assurance standard requires, and a governance record. The first is a retrieval task for finance, the second can be bought, and the third is a discipline rather than a headcount. A first-year filing is a defined project, which is why a permanent hire is usually the wrong first move.
Where this sits commercially
Carbonhalo builds the working paper file; it never assures it.
Other terms in this cluster
Working papers (climate disclosure)