CSRD supply chain reporting: what UK companies are being asked for, and why

Why CSRD Extends to Your Suppliers

CSRD's ESRS E1 standard mandates that companies disclose their Scope 3 Category 1 emissions — the greenhouse gases embedded in purchased goods and services — covering the entire upstream supply chain. This is not an optional disclosure: for companies within scope, it is a required element of their sustainability statement, subject to external verification.

The direct compliance threshold catches companies with more than 250 employees, €40 million in revenue, or €20 million in total assets. But the indirect pressure extends far beyond that: every EU company filing under CSRD needs primary data from the suppliers who make their Scope 3 calculation possible. If you supply into EU value chains, the data request will reach you.

Failure to report accurately — or to provide auditable supplier data — carries real consequences. Regulatory penalties apply to the EU reporter, but the commercial signal flows upstream: suppliers who cannot provide documented emissions data risk losing procurement advantage to competitors who can.

• ESRS E1 requires Scope 3 Category 1 disclosure
• EU verifiers need traceable, auditable supplier figures
• Non-compliance risks regulatory penalties and reputational damage
• Investors and customers are demanding transparency on supply chain emissions

Building a Supplier Engagement Programme

Successful CSRD compliance requires a tiered engagement approach that matches data collection effort to commercial significance and emission impact. Not every supplier needs the same level of engagement — the goal is to cover at least 80% of your Scope 3 Category 1 emissions by spend or volume with primary or high-quality secondary data.

Tier 1 — Direct suppliers: Collect primary data via supplier questionnaires, API integration, or your procurement platform. These suppliers represent your highest-spend, highest-impact relationships and should be engaged first.

Tier 2 — Sub-suppliers: Use spend-based estimates with validated emission factors. Where spend data is available, the GHG Protocol Category 1 methodology provides a defensible interim approach.

Tier 3 — Raw material origin: Use industry averages from IPCC AR6 or sector databases. Document the methodology clearly in your ESRS disclosure.

Set a 12-month data collection timeline with quarterly supplier check-ins. Prioritise by spend volume and emission intensity — the 20% of suppliers representing 80% of your footprint is where to concentrate first-year effort.