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

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
• CDP: value chain engagement for a small supplier
• Scope 3 supplier evidence

Sources: GHG Protocol, Corporate Value Chain (Scope 3) Accounting and Reporting Standard

Last reviewed 2026-11-04.