What evidence do we need to support our assessment?

An auditor needs to trace every materiality conclusion back to its source. That means a standalone methodology document, scoring templates and completed scorecards, the topic longlist and screening decisions, your ESRS 1 Appendix A cross-mapping table, records of stakeholder consultation, and minutes or notes covering the judgement calls and who made them.

Why the file matters more than the conclusion

A DMA without an evidence trail is a set of opinions. The result may well be correct, but if the auditor can’t see how each conclusion was reached, the conclusions don’t stand.

Under limited assurance, the methodology is examined alongside the outcome. That’s unchanged under the revised ESRS, which cut mandatory datapoints by 61% and left the standard of evidence behind your materiality decisions where it was.

What to keep

A standalone methodology document. Updated as you go, ready to hand to your assurance team from the first day rather than assembled when they ask.

Defined materiality threshold and cutoff criteria. Under the ESRS, the auditor specifically looks for documented quantitative and qualitative thresholds. 

Value chain scope and boundary assumptions. Showing where a company drew the line upstream and downstream is always high on the auditor’s request list. 

Scorecards and scoring templates. Including the version history, if the criteria changed partway through. The rationale for scoring is also useful and can be included as part of these documents. 

The topic longlist and every screening decision. Particularly the exclusions. The reasoning behind why you decided not to report on something is the part auditors ask about, and it’s the part teams most often never wrote down.

The cross-mapping table against ESRS 1 Appendix A, showing you screened the full universe of topics.

Stakeholder consultation records. Who you spoke to, what methodology you used, what came back, and how you processed what came back.

Meeting minutes and decision notes. Including changes of approach. If the assessment changed direction, an auditor wants to see when and why, rather than finding contradictory versions with no explanation between them.

The test

Here’s the test we use, and it’s more demanding than it sounds.

If a junior team member sat down a year from now, with no involvement in the original assessment and no access to anyone who was there, could they reconstruct the logic of any given conclusion from the documentation alone?

If not, the documentation isn’t doing its job. It may feel complete to the people who lived through the process, because they carry the context in their heads. That context is what’s missing when someone else picks the file up, and staff turnover means someone else usually does. 

Build it as you go

Every methodological decision, scoring rationale and stakeholder consultation should generate a record at the moment it happens. The methodology and the evidence file should grow alongside the assessment.

The alternative is reconstruction from memory and email threads, months later, under deadline. We’ve watched teams do it. It takes longer than doing it properly would have, and the result is weaker, because the reasoning recorded after the fact is the reasoning you can remember rather than the reasoning you applied.

Problems found early in a DMA are a conversation. The same problems found under audit are a project.

Kōan has worked on materiality assessments for 9 years, with companies from listed multinationals to first-time reporters across Europe, Asia and the US. If you want a second pair of eyes on your methodology before your auditor finds the gaps, get in touch.

Dixie De Winne, Kōan
Published 07 October 2026 · Last reviewed 23 September 2026

Dixie De Winne works on reporting and regulatory projects at Kōan, including double materiality assessments, gap analyses and reporting roadmaps.