A programme designed from the standards forward does the opposite: it asks fewer suppliers for a defined set of items, in a shape the supplier can reuse. The GHG Protocol is specific about what to request, in what order, and from whom.
Summary
- Design the programme around prioritised activities and tier 1 suppliers, not around universal coverage.
- The GHG Protocol specifies what to request from a supplier: Scope 1 and 2 emissions, methodology and data sources, allocation method, and assurance status.
- Ask for data as specific to the purchased product as the supplier can provide, following the standard's specificity hierarchy.
- Overlap between buyers is the dominant burden. Across 12 real questionnaires EFRAG analysed, energy and greenhouse gas emissions were requested in every one.
- Align to a recognised structure so the supplier's answer is reusable, rather than inventing a bespoke template.
Start With Who You Actually Need Data From
The GHG Protocol sequences this deliberately. Prioritise scope 3 activities first, then select data based on business goals, the relative significance of each activity, and the availability and quality of data. Collect high quality primary data for high priority activities, and particularly for activities targeted for emissions reductions ghgprotocol.org.
On who to approach, the standard directs companies to engage relevant tier 1 suppliers first, since a purchase order relationship provides the leverage to request inventory data.
It observes that a company may have many small tier 1 suppliers that together make up only a small share of total spend, and that companies may set their own policy for selecting targets, for example by contribution to total spend.
It also sets expectations honestly: it is unlikely that all of a company's relevant suppliers will be able to provide GHG inventory data. Where they cannot, the guidance is to use secondary data and encourage suppliers to develop inventories over time.
What to Ask For
The standard lists what a buyer may request from a supplier or value chain partner. Using this list rather than an invented one keeps the request defensible and comparable.
Requests that go beyond this set should be justified by a specific reporting need. Each additional item lowers completion rates without necessarily improving the inventory.
Ask at the Right Level of Detail
The standard ranks levels of data by specificity, and asks companies to seek data as specific as possible to the product purchased, because product-level data avoids the need for allocation.
- Product-level: cradle-to-gate emissions for the product of interest
- Activity, process or production line-level
- Facility-level
- Business unit-level
- Corporate-level
Designing the questionnaire so a supplier can answer at whichever level they hold data, rather than failing the question entirely, is the single most useful structural decision. Granularity matters most for diversified suppliers producing a wide range of products, where a corporate-level figure says very little about what you bought.
Why Response Rates Fall
Two factors are worth separating, because they are often merged into a claim that does not hold.
The first is scope: a questionnaire that asks a supplier for things they cannot produce returns blanks regardless of how it is worded. The second is duplication across buyers, which is real but currently smaller than commonly asserted.
EFRAG found that in 2023 most SMEs received only one ESG request a year, in a simple format, at limited cost. The duplication sits in how separately those instruments are built, and the burden is expected to grow as reporting obligations widen rather than being acute today.
EFRAG's secretariat analysed 12 real ESG questionnaires, issued by national central banks, national federations, banks, a rating agency and mixed bank and supply chain initiatives. They cover around 26,000 SMEs, within initiatives comprising roughly 700 banks and 450 value chain companies. A separate rating agency questionnaire in the sample is used by more than 100,000 companies efrag.org.
The overlap across those questionnaires:
A bespoke template adds to that load without adding information. A template aligned to a recognised structure lets the supplier reuse an answer they have already prepared.
Design for Reuse, Not Just Collection
The regulatory direction reinforces this. The European Commission's 2025 recommendation on voluntary SME reporting sets out to reduce the need for SMEs to respond to separate requests from individual counterparties eur-lex.europa.eu. Directive (EU) 2026/470 gives companies averaging 1,000 employees or fewer in a reporting company's value chain the right to decline requests exceeding the voluntary standard eur-lex.europa.eu.
A programme built on a recognised structure keeps working under that regime. One built on a proprietary 60-item form does not.
Set the Right Success Measure
The GHG Protocol requires companies to report a description of the types and sources of data used, and the percentage of emissions calculated using data obtained from suppliers or other value chain partners. That percentage is the measure worth tracking, because it only improves when suppliers in priority categories actually report.
Questionnaires sent, or raw response rate across the whole base, both improve by contacting more low-significance suppliers. Neither indicates a better inventory.
Frequently Asked Questions
How long should a supplier ESG questionnaire be?
No standard sets a length. A defensible scope is the item list the GHG Protocol specifies for supplier requests, with anything beyond it justified by a stated reporting need.
Should every supplier get the same questionnaire?
No. The standard's approach is to prioritise activities, engage tier 1 suppliers in priority categories, and use secondary data for activities that are not prioritised or where a supplier cannot provide data of sufficient quality.
Which frameworks should the questionnaire align to?
Ask for Scope 1 and 2 on a GHG Protocol Corporate Standard basis, and product data on a Product Standard basis, since these are what the Scope 3 Standard names. For smaller suppliers, the EU's voluntary SME standard is the structure regulators are steering towards.
Can a supplier reuse the same ESG data for multiple buyers?
That is the intent behind aligning to recognised structures rather than proprietary templates. The same underlying figures, prepared once on a recognised basis, can answer multiple buyers where each buyer accepts that structure.
What if a supplier cannot provide data at all?
Use secondary data for that activity. The standard anticipates this directly and directs companies to encourage those suppliers to develop inventories over time.
About Gprnt
Gprnt is sustainability data infrastructure launched by the Monetary Authority of Singapore (MAS) and operated by the Global Finance & Technology Network (GFTN), open digital infrastructure accessible to businesses of every size.
Its Value Chain Intelligence pillar collects supplier sustainability data for Scope 3, procurement and financing through a shared layer rather than buyer-specific questionnaires. Entry-level Scope 1 and 2 reporting is free for SMEs, and reports are audit-friendly and aligned with the GHG Protocol and ISSB standards.
To see how supplier data collection works when suppliers report once rather than per buyer, visit gprnt.ai.
References
- GHG Protocol, Corporate Value Chain (Scope 3) Accounting and Reporting Standard, sections 7.1, 7.3 and 7.4, tables 7.5 and 7.7 (ghgprotocol.org)
- GHG Protocol, Technical Guidance for Calculating Scope 3 Emissions (ghgprotocol.org)
- EFRAG, VSME Exposure Draft Basis for Conclusions (January 2024), BC44 and BC45 (efrag.org)
- Commission Recommendation (EU) 2025/1710 on a voluntary sustainability reporting standard for SMEs (eur-lex.europa.eu)
- Directive (EU) 2026/470 (eur-lex.europa.eu)