# Our buyer wants us to collect carbon data from our own suppliers too. What does that mean?

Canonical: https://senseible.earth/answers/buyer-asks-us-to-collect-carbon-data-from-our-suppliers

It is called cascading. The GHG Protocol says a company should engage its direct suppliers first, then may ask them to encourage their own suppliers, and target second-tier suppliers only where they cause most of a product's emissions. Start with the few suppliers behind most of your emissions, and ask for data they already hold.

## What the standard describes

- Companies should first engage tier 1 suppliers, because large impacts often sit further upstream.
- Encourage tier 1 suppliers to ask their own suppliers, the buyer's tier 2, to report their inventories, and eventually ask tier 2 to do the same.
- Target specific tier 2 suppliers where they are responsible for the majority of the emissions of a product bought from a tier 1 supplier. The standard calls this likely difficult without close cooperation between a company and its supply chain.

## How to keep it manageable

- Pick suppliers by their share of your emissions or your purchases, not all of them.
- Ask for energy-use data they already collect, rather than emissions data.
- Send a short template and a clear list of what to attach, such as electricity and fuel bills.
- Combine your request with your buyer's so suppliers answer once.
- Follow up.

## What you owe your buyer

Usually a date and a method, not a finished answer. Tell the buyer which suppliers you will start with and why.

## What Senseible does here

Senseible turns your bills and invoices into verified emission records by site, so you can answer a buyer with figures you can trace to a document. Verified here means rule checks passed against the evidence. It is not third-party assurance.

- [Which suppliers to engage first on Scope 3](https://senseible.earth/answers/which-suppliers-to-engage-first-on-scope-3)
- [CDP: value chain engagement for a small supplier](https://senseible.earth/answers/cdp-value-chain-engagement-small-supplier)
- [Scope 3 supplier evidence](https://senseible.earth/scope-3-supplier-evidence)

Sources: [GHG Protocol, Corporate Value Chain (Scope 3) Accounting and Reporting Standard](https://ghgprotocol.org/sites/default/files/standards/Corporate-Value-Chain-Accounting-Reporing-Standard_041613_2.pdf)

Last reviewed 2026-11-04.