A customer can ask a supplier for many different types of carbon information — but that does not mean every request has the same purpose, scope or level of detail.
The practical first step is to identify what decision the customer is trying to make: calculate its Scope 3 inventory, assess supplier risk, prepare a disclosure, compare products, verify a target, or satisfy a procurement requirement.
This guide explains the most common categories of carbon-data requests suppliers receive, what evidence may sit behind them, and an important 2026 EU development that can limit value-chain information requests for certain smaller companies. To assess which records and evidence your organization can actually provide, use our Carbon Data Readiness Assessment.
The short answer
Customers commonly request organizational emissions, product carbon data, activity data, methodology details, emission-factor sources, targets, assurance status and supporting evidence. Some requests are voluntary or contractual. Others are linked to the customer’s own reporting obligations.
Do not assume that “carbon data” means a complete Scope 1, 2 and 3 inventory. Ask what boundary, period, product or category is actually required.
1. Scope 1 emissions
A customer may ask for emissions from sources your company owns or controls. Depending on your operations, the underlying data can include fuel consumed in boilers or generators, company vehicles and refrigerant losses.
2. Scope 2 emissions
This usually means emissions associated with purchased electricity and other purchased energy. A questionnaire may ask for consumption, reported Scope 2 emissions, the method used and supporting utility or meter data.
3. Scope 3 emissions
A customer may ask for your complete Scope 3 inventory, selected categories, or supplier-specific data that feeds into its Scope 3 calculation. The GHG Protocol Corporate Value Chain (Scope 3) Standard organizes Scope 3 into 15 upstream and downstream categories and is intended to help companies understand value-chain emissions and where to focus reduction activity. See the GHG Protocol Scope 3 Standard.
If a customer simply says “provide Scope 3,” ask whether it wants a full inventory or only categories relevant to your commercial relationship. For calculation options, see our comparison of spend-based, activity-based and supplier-specific Scope 3 methods.
4. Product carbon footprint data
Product-level requests are different from corporate inventories. A customer may ask for the emissions associated with a particular product, material, component or service rather than your whole company.
GHG Protocol distinguishes corporate value-chain accounting from product-level accounting: its Product Standard focuses on emissions associated with an individual product life cycle, while the Scope 3 Standard is corporate-level. See the GHG Protocol Product Standard.
5. Activity data rather than calculated emissions
Sometimes the customer does not want your final tCO2e figure. It may want the underlying activity data so it can calculate emissions itself.
| Request | Example supplier data |
|---|---|
| Purchased goods | Mass, quantity, spend, material composition |
| Transport | Mode, distance, weight, lane, fuel |
| Energy | kWh, fuel volume, meter data |
| Business travel | Distance, travel class, hotel nights |
| Waste | Mass, waste type, treatment route |
| Product use | Lifetime, energy use, usage assumptions |
6. Supplier-specific or primary data
A customer may ask you to replace generic estimates with data specific to your organization, facility or product. This can improve the customer’s Scope 3 data quality, but the request should still make the required boundary, period and methodology clear.
7. Methodology, emission factors and assumptions
Expect questions such as which standard you followed, which emission factors you used, whether data is primary or estimated, how organizational boundaries were defined and what exclusions or assumptions were made.
8. Verification or assurance
A customer can ask whether figures have been independently verified or assured. Answer precisely. Internal review, consultant support, automated software calculations and independent assurance are not the same thing.
9. Targets, transition plans and reduction actions
Supplier questionnaires may go beyond historical emissions. Customers can ask whether you have reduction targets, renewable-energy initiatives, supplier programs, product redesign measures or other decarbonization actions.
10. Disclosure through a customer platform
Some buyers use external disclosure systems rather than their own spreadsheet. CDP’s Supply Chain program, for example, allows purchasing organizations to request environmental disclosure from suppliers. Its 2026 supplier-engagement guidance emphasizes explaining why disclosure is being requested and how supplier information will be used, including to improve Scope 3 accounting. See CDP Request Data.
Important 2026 EU update: the value-chain cap
In July 2026, the European Commission adopted revised European Sustainability Reporting Standards (ESRS) together with a voluntary reporting standard for smaller companies outside the CSRD scope. According to the Commission, the voluntary standard is intended to help smaller companies respond to sustainability-information requests from larger companies and financial institutions.
The Commission also states that the new value-chain cap means companies subject to the CSRD cannot require companies in their value chains to provide more information than is covered by the voluntary standard. The measures were adopted on 3 July 2026 and were subject to scrutiny by the European Parliament and Council before application.
Source: European Commission — revised sustainability reporting standards, 3 July 2026.
Practical implication: an EU customer request should not automatically be treated as unlimited. If the request is linked to CSRD value-chain reporting and your company is protected by the cap, check the applicable voluntary-standard boundary before supplying information beyond it. This is a compliance question, so confirm the current legal position when responding.
What should you clarify before answering?
- Which legal entity, facility, product or service is in scope?
- Which reporting period should be used?
- Does the customer want calculated emissions or underlying activity data?
- Which Scope 3 categories are required?
- Is product-level or corporate-level accounting expected?
- Which methodology or emission-factor source is required?
- Are estimates acceptable where primary data is unavailable?
- Is verification or assurance required?
- What evidence must be attached?
- What is the deadline and required submission format?
FREE TOOL
Not sure what the customer is really asking for?
Paste the exact wording into the Carbon Request Decoder. It will identify likely scopes, reporting period, methodology language, data needs and questions worth clarifying.
The key distinction: request, requirement and good practice
A customer being able to ask for information does not automatically mean every requested datapoint is legally mandatory for the supplier. The answer may depend on contract terms, procurement rules, the reporting framework behind the request, the supplier’s jurisdiction and any applicable value-chain limits. For the distinction between commercial requests and legal obligations, see Do You Have to Provide Carbon Data to Your Customers?
For that reason, classify every request into three buckets: explicitly required, requested but negotiable/clarifiable, and useful voluntary information. That simple distinction can prevent unnecessary work and unsupported claims.
About this guide
Scope3Analytics prioritizes primary sources. This guide references the GHG Protocol Corporate Value Chain (Scope 3) Standard, the GHG Protocol Product Standard, CDP supplier-disclosure materials and the European Commission’s July 2026 sustainability-reporting update.
Last reviewed: October 4, 2026