What are the biggest mistakes companies make in a double materiality assessment?

The eight we see most often: poor scoping, scoring human rights impacts on likelihood rather than severity, running the assessment inside the sustainability function alone, a methodology that isn’t applied consistently, treating the DMA as a one-off, getting the timing wrong, thin documentation, and overlooking dependencies. Most trace back to decisions made in the first few weeks.

1. Poor scoping

Starting without defined boundaries is the most common way this work goes sideways. Which entities are in, which geographies count, whether joint ventures sit inside the boundary, where the value chain analysis stops. Without those fixed at the start, every later decision wobbles, and conclusions can’t be defended in assurance because the boundary was unclear when the assessment was made.

Define scope before any other work begins and treat it as fixed unless the business itself changes.

2. Scoring human rights impacts incorrectly

Most methodologies weight severity and likelihood equally. Under the ESRS, severity takes priority for human rights impacts.

Take child labour in the supply chain. A company reviews its history, its supplier audits and its contracts, concludes likelihood is low, and the impact drops out as non-material. But child labour is a severe human rights impact, and that severity should outweigh the low likelihood. Assessed properly it stays material even though it probably won’t happen.

Because the error sits in the scoring logic rather than in one conclusion, fixing it means revisiting everything it touched.

3. Running it in isolation

Sustainability usually leads the DMA, and that’s fine. Someone has to own it. The problem starts when leading it becomes doing it alone.

Sustainability teams rarely hold the full picture on operational risk, supply chain dependencies, workforce data or governance. Without risk, strategy, procurement, HR, finance and legal involved, you get blind spots the function had no way of knowing were there, and conclusions that can’t be corroborated when an auditor cross-checks with the team that holds the data.

Bring those functions in early enough to shape conclusions rather than sign them off.

4. A methodology that doesn’t hold up

Different assessors applying different logic to the same criteria. Inconsistent scoring. Judgement calls made and not documented. By the time an auditor pulls on threads, the inconsistencies are everywhere with no rationale to point back to.

Agree criteria and thresholds before you start, write down the reasoning, and apply them consistently.

5. Treating it as a one-off

The assessment is completed, signed off, published, and everyone moves on. The next cycle starts from scratch because the methodology and evidence were never stored in a way anyone could pick up a year later.

Design the first assessment with the second in mind. Set the triggers for review, assign ownership of tracking them, and keep the file legible to people who weren’t involved.

6. Getting the timing wrong

Start too late and the parts that get squeezed are the ones auditors examine hardest. Start too early and you spend the same effort on an assessment that no longer reflects the business.

Plan backwards from the deadline, allow more room than feels necessary, and add a checkpoint before you report.

7. Thin documentation

A DMA without an evidence trail is a set of opinions. The result may look credible, but if the auditor can’t see how each conclusion was reached, it doesn’t stand.

Build the evidence file as the assessment progresses. If a junior colleague couldn’t reconstruct a conclusion from the documentation alone a year later, the documentation isn’t doing its job.

8. Overlooking dependencies

Most assessments handle impacts and visible financial risks reasonably well. The blind spot is dependencies, meaning the things the business needs to operate but doesn’t control. Water access. Stable climate conditions in growing regions. Intact ecosystems producing your inputs. A workforce with the right skills in the right places.

Companies assess the risks they can already see, such as regulation, reputation and supply chain disruption, and miss the dependencies those risks sit downstream of. Dependencies are required under the ESRS, so omitting them is a compliance failure. The larger cost is strategic, because a strategy built on an assessment that never identified them was built without knowing what the business relies on.

What they have in common

All 8 trace back to early decisions. What the scope covers, who’s involved, how the evidence gets built. The cost surfaces much later, under audit, under deadline, or at the start of the next cycle. By then the fix costs more than the assessment did.

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 28 October 2026 · Last reviewed 09 October 2026

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