Data & evidence

Audit trail

The record of where every reported figure came from — the source document, the calculation applied, who changed it, when, and why. Not a log of system activity, but a defensible chain from raw evidence to published number.

Corewell covered

What it is

The audit trail is where sustainability reporting most resembles financial reporting, and it's the part most companies underestimate. An assurance provider works backwards. They select a figure in your disclosure and ask to see the evidence behind it — the invoice, the meter reading, the supplier statement. Then they ask what was done to it: which factor was applied, what assumptions were made, whether anyone adjusted it after the fact and on what basis. If any link in that chain is missing, the figure can't be assured, regardless of whether it's correct. This is why spreadsheets fail at scale. Not because they calculate wrongly, but because they don't retain the history of how a cell reached its value. The number survives; the reasoning doesn't. Building the trail retrospectively, in the weeks before assurance, is the most expensive way to do it — and the most common.

Why it matters

Assurance is not an examination of your numbers. It is an examination of whether you can show how you got them. A company with good data and no trail fails; a company with imperfect data and a complete trail usually passes with qualifications.

How it connects

reports on

Read more from Sprih