Write a supplier emissions request that returns usable data

Fictional example: 8,000 brackets give 20 t CO2e on a cradle-to-gate basis. The unmatched 600 t corporate total stays outside the calculation. The factor is invented and must not be used for actual reporting. This is not an achieved reduction.

Build the request around the purchase record you need to calculate. A supplier can answer promptly with an annual corporate total and still leave your purchased-goods calculation unresolved. Show the product, quantity and intended use before asking for an emissions number.

This guide is for procurement and corporate inventory teams collecting data for Scope 3 Category 1, purchased goods and services. It gives an illustrative request and shows what to do with three kinds of reply.

Choose the calculation route before sending the request

The GHG Protocol Category 1 guidance distinguishes two routes involving supplier data:

• Supplier-specific method: uses product-level cradle-to-gate emissions data from the supplier.

• Hybrid method: combines supplier data, including allocated Scope 1 and Scope 2 emissions, with other upstream activity data and secondary estimates where needed.

Cradle-to-gate covers production through the supplier's gate, including relevant upstream stages. Supplier-to-buyer transport in vehicles outside the buyer's ownership or control is accounted for in Category 4. Keep that leg identifiable. GHG Protocol Category 1 guidance, printed pages 20–26

If the brief still says only “carbon footprint”, resolve the accounting object first using the corporate and product footprint scoping guide.

Give the supplier a purchase record it can recognise

In this fictional example, a buyer's reconciled purchase register contains 8,000 coated brackets, product BR-24, for 1 April 2025 to 31 March 2026. The figure already reflects the buyer's inventory treatment of returns and credit notes. All quantities, product codes, replies and emissions values in this guide are invented.

The buyer prepares an attachment listing its order references, the supplier's product code, specification and quantities. This lets the supplier flag a different code or missing order without reconstructing the buyer's records. The following wording is an adaptable example, not a prescribed GHG Protocol form.

Subject: Emissions data for BR-24 purchases, April 2025 to March 2026

We are preparing our corporate purchased-goods inventory. Our attached schedule lists 8,000 BR-24 coated brackets purchased during the stated period. Please confirm the specification and quantities, or mark differences against the order references.

1. Product and unit: identify the supplying factory and provide available emissions per finished BR-24 bracket. For results per kilogram or another unit, state that unit and provide the conversion information.

2. Boundary: describe the stages covered through the factory gate, including the coating operation. Identify exclusions and show delivery to us separately if it is included in your existing study.

3. Period: state the dates represented by the underlying data and explain any difference from our purchase period.

4. Calculation: reference the method, factor sources and global warming potential basis used to express greenhouse gases as carbon dioxide equivalent. Explain any allocation, including the basis and quantities used.

5. Evidence: provide the calculation reference, important estimates and limitations. State whether independent verification covers this particular result and provide its scope if available.

6. Unavailable information: identify gaps explicitly. If no product result is available, describe the production or activity records you can supply and the person who can explain them.

Please return the completed schedule through our agreed channel by [agreed date]. Flag restrictions on using or sharing the information before sending restricted records. We can agree a proportionate evidence route with the relevant data owner.

Replace the date and channel before sending. GHG Protocol's supplier engagement guidance supports explaining data use, agreeing collection arrangements and following up on questions. Its Scope 3 Standard addresses supplier methodology, allocation and supporting evidence. Supplier Engagement Guidance, pages 4–6; Scope 3 Standard, chapters 7 and 8

Ask a follow-up that identifies the missing decision

Suppose the first reply attaches a corporate inventory reporting 600 tonnes CO2e and adds “BR-24: 2.5 kg CO2e” in an email. The product entry gives no denominator, period or boundary. Keep both records, but hold the product number from the calculation.

A useful follow-up is: “Does 2.5 kg CO2e mean per finished coated bracket? Please identify the calculation version, supplying factory and data period, confirm the included stages, and explain any allocation. Our order schedule totals 8,000 units. Please identify any lines your result does not cover.”

This question tells the supplier exactly what would change the decision. Re-sending a blank questionnaire gives it less direction. The 600-tonne corporate inventory may supply context for further work; it does not establish the emissions attributable to these purchases.

Give each reply a calculation decision

1. Use a supported product result. Assume the follow-up in this fictional case resolves the product, unit, factory, period and cradle-to-gate boundary. The supporting calculation explains allocation and limitations, and the reviewer considers its quality sufficient for the inventory's purpose. Only under those assumptions does the invented 2.5 kg CO2e per bracket enter the calculation.

2. Use partial records as inputs for further calculation. If the supplier instead provides allocated production emissions, retain the supported inputs and identify the upstream gaps. A hybrid calculation needs appropriate completion of those gaps. Adding a whole cradle-to-gate secondary factor to allocated production emissions can count the same production twice. Category 1 guidance, printed pages 25–26

3. Hold an unmatched response. A total for another product, an unexplained company-wide number or an unresolved unit stays outside this calculation. Keep the purchase row open for an appropriate estimate or further evidence. Missing supplier data does not make the purchase zero-emission.

Supplier origin alone is not a quality test. Review whether the data represents the relevant technology, time and geography, and assess completeness and reliability. Record the reason for using it. Scope 3 Standard, section 7.3

Reconcile the accepted result to the purchase

For the fully matched fictional response: 8,000 brackets × 2.5 kg CO2e per bracket = 20,000 kg CO2e, or 20 tonnes CO2e.

That result covers the stated bracket purchases under the example's assumptions. Do not add the supplier's 600-tonne corporate total. Do not apply the factor to another bracket or to orders left unmatched. The invented factor must not be used for actual reporting.

Save the accepted response version beside the purchase schedule and calculation. Record who approved its use, what remains estimated and which earlier record it replaces. The supplier ESG response tracker can organise the exchange; the inventory workbook still needs this topic-specific calculation decision.

Prepare the inventory evidence

Nitium's carbon inventory support covers corporate inventory preparation, calculation workbooks, source and assumptions records, and data gaps within an agreed scope. Discuss your inventory needs with the reporting period and a non-confidential description of the supplier-data issue.

Sources checked 13 October 2026. This guide uses the 2011 Scope 3 Standard and 2013 Category 1 calculation guidance. The example is fictional and simplified; it is not a product certification, legal opinion or independent assurance conclusion.