CSRD requires reporting companies to include sustainability information about their value chain — their upstream suppliers and downstream customers. This makes CSRD a supply chain issue, not just a large-company reporting issue. If you are a supplier to any company subject to CSRD, you will be asked for sustainability data. Understanding what they need — and why — helps you prepare efficiently.
Why Value Chain Reporting Is Significant
ESRS 1 (the foundational cross-cutting standard) defines "sustainability reporting" to include material impacts, risks, and opportunities across the full value chain — not just within the company's own operations.
For CSRD-reporting companies, this means:
ESRS E1 (climate): Scope 3 Category 1 (purchased goods and services) requires estimating emissions from everything the company buys. For many companies, this is the largest emission category — often 60–80% of total GHG footprint. Reliable Scope 3 data requires supplier-level information.
ESRS S2 (workers in the value chain): Requires disclosure of how the company assesses and addresses human rights risks in its supply chain — working conditions, wages, health and safety for upstream workers.
ESRS G1 (business conduct): Supply chain due diligence for anti-corruption, forced labour, and supply chain governance.
What CSRD Companies Will Ask Their Suppliers
Wave 2 companies (reporting from FY 2025) will begin issuing value chain questionnaires to significant suppliers. Expect requests for:
Climate Data (ESRS E1)
GHG emissions:
- Scope 1 emissions (metric tonnes CO₂e) — your direct emissions
- Scope 2 emissions (metric tonnes CO₂e) — emissions from your purchased energy
- Scope 3 emissions — if you report them
Energy consumption:
- Total energy consumed (MWh)
- Renewable energy percentage
Product-level carbon footprints:
- For product manufacturers: emissions per unit or per kg of product supplied
- For service companies: emissions per currency unit of service provided or per service unit
Climate targets:
- Do you have a net-zero or emissions reduction target?
- What year and baseline?
- Science-Based Target Initiative (SBTi) validation?
Workforce and Social Data (ESRS S2)
Labour standards:
- Do you have a Code of Conduct for suppliers?
- Are your workers paid at or above the living wage in each operating country?
- What percentage of your workforce is covered by collective bargaining?
Health and safety:
- Total recordable incident rate (TRIR)
- Work-related fatalities
Human rights:
- Do you have a human rights policy?
- Do you conduct human rights due diligence (aligned with EU Corporate Sustainability Due Diligence Directive — CSDDD)?
- Supply chain audits or certifications (SA8000, SMETA, etc.)?
Business Conduct (ESRS G1)
Anti-corruption:
- Anti-bribery policy in place?
- Training on anti-corruption?
- Any enforcement actions or material legal proceedings?
The EU Corporate Sustainability Due Diligence Directive (CSDDD) — Context
Separate from CSRD, the CSDDD (adopted 2024) requires large EU companies to conduct due diligence on their supply chains — identifying and addressing adverse human rights and environmental impacts. CSDDD applies to companies with 1,000+ employees and €450M+ global turnover.
Interaction with CSRD: CSRD and CSDDD create complementary pressure on supply chains. CSRD creates the reporting obligation; CSDDD creates the due diligence obligation that generates the data to report. Suppliers to large EU companies will face both streams of requirements.
How to Prepare as a Supplier
Tier 1: Immediate Actions
Carbon measurement: Start measuring your Scope 1 and Scope 2 emissions if you have not done so. This is the single most commonly requested data point. Free tools: SME Climate Hub carbon calculator, national government carbon calculators.
Energy data: Know your annual energy consumption (from utility bills) and your renewable energy percentage.
Basic policies: Document your environmental policy, health and safety policy, and anti-bribery policy. These are quick to prepare and are standard requests.
Tier 2: Within 12 Months
Workforce data: Build the capability to report TRIR, gender breakdown, and pay gap data. Most of this is in HR systems already.
Product carbon footprint estimate: For manufacturers, develop a methodology for estimating embodied carbon in your products. Spend-based estimates are acceptable as a starting point.
SBTi commitment: Consider committing to Science-Based Targets — this is increasingly a qualification criterion in enterprise procurement for sustainability-focused customers.
Tier 3: Ongoing
Supplier code of conduct: Develop and deploy a supplier code of conduct that flows sustainability expectations to your own supply chain.
Annual reporting: Build a simple annual sustainability report covering the metrics above. This can be prepared using the ESRS VSME standard (voluntary SME standard) — which is aligned with what large company customers need.
Working with Customer Data Requests Efficiently
If multiple large customers are requesting sustainability data, use a standardised response:
- A single master dataset covering all commonly requested metrics
- A mapping document showing which customer's questionnaire maps to which data point
- A standard data sharing agreement with customers receiving your sustainability data
Platforms that aggregate supplier sustainability data (EcoVadis, Sedex, CDP supply chain) allow you to complete one questionnaire and share responses with multiple customers — reducing the administrative burden.