Supplier assessment for sustainability: a practical guide for buyers

Why supplier assessment now works differently

Supplier assessment for sustainability is no longer a voluntary exercise. If your company is CSRD-reporting, you are legally required to report your scope 3 emissions — and category 1 (purchased goods and services) sits with your suppliers.

This means your procurement process and your sustainability reporting are genuinely connected for the first time. The data your suppliers provide must be primary (directly from the source), structured (comparable between suppliers), and traceable (with calculation documentation for your auditor).

Self-made Excel forms rarely meet these requirements. This article explains how to do it better.

What data do you need from your suppliers?

For your ESRS E1 disclosure, you need at minimum from your suppliers:

Scope 1 and 2 emissions (tonnes CO₂e) — for calculating your scope 3 category 1. These are the direct emissions of your supplier itself. Energy consumption (MWh electricity and gas) — if the supplier hasn't calculated their emissions, you can do so yourself using activity data and emission factors. Company details (sector, FTE, locations) — for weighting and segmentation in your own report.

Additionally, for a complete VS Standard assessment: water consumption, waste data, workforce figures, and policy documents.

What you cannot request (value chain cap): a full LCA, the supplier's own scope 3 emissions, or company-specific production data outside the VS Standard.

How do you request this in a structured way?

The most common mistake: sending your own Excel template that your supplier fills in their own way. Result: inconsistent data, missing calculation documentation, and an audit trail your auditor won't accept.

The better approach in three steps:

Step 1 — Ask your suppliers to create a VS Standard (VSME) profile on a standardised platform. That way you know the data has been calculated according to the same standard and the same emission factors.

Step 2 — Send a structured request link via the platform. The supplier approves the request and you receive the data in a format directly importable into your CSRD reporting tool (Greenly, Normative, Coolset).

Step 3 — Aggregate the scope 3 category 1 data per supplier, weighted by purchase amount. That's the input for your ESRS E1 disclosure.

verified.supply offers this enterprise dashboard. Invite your suppliers, track progress per supplier, and export the aggregated scope 3 data directly to your reporting tool. Sign up as an enterprise buyer at verified.supply.