# Why would a big customer care about my small business's carbon?

Canonical: https://senseible.earth/answers/why-big-customers-ask-small-suppliers-for-carbon

Because what you sell is part of their footprint, and your emissions are a big part of it. The Greenhouse Gas (GHG) Protocol says Scope 3, the emissions from a company's value chain such as the goods it buys, can be the largest source of emissions for a company. A buyer cannot see yours unless you tell it.

## The back-door picture

A restaurant's footprint is not only its own stove and lights. It includes the farm that grew the vegetables, the lorry that brought them and the maker of the plates. The restaurant cannot read those numbers off its own bills. It has to ask.

You are one of those farms or lorries for your customer. Your own Scope 1 and 2 are, in my reading, part of the customer's Scope 3 under goods it buys.

## What the standard says

- Scope 3 Standard: significant emissions result from value chain activities not captured by Scope 1 and Scope 2 inventories.
- It adds that Scope 3 emissions can represent the largest source of emissions for companies and present the most significant opportunities to influence reductions.
- It says a company may engage its major suppliers to obtain emissions information on the products it purchases.

## What a fair request looks like

The standard's advice to buyers is to make the data request as simple as possible and to provide a clear list of data required and where to find it, for example utility bills. It also suggests asking for activity data, such as kilowatt hours of electricity or kilograms of fuel used, and calculating the emissions separately, which cuts mistakes. If a request is more complicated than that, you can ask the buyer to simplify it.

## Is it an order?

Not by itself. The standards are not law (see the linked page). It is the buyer's condition for doing business, so check what it is tied to, such as a supplier code, a loan term or a rule it must follow, and answer that.

## Example: the three numbers that answer most first requests

- Electricity used last year: 10,200 kilowatt hours (kWh)
- Fuel used last year: 960 litres of diesel
- Your calculated Scope 1 and 2: 960 x 2.645 = 2,539.2 kilograms (kg) plus 10,200 x 0.675 = 6,885 kg, which is 9,424.2 kg, about 9.4 tonnes

Example quantities for a small workshop. The grid factor is for financial year (FY) 2025-26.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into records, so the quantities behind each figure are on file. Those two sets of quantities answer the first request. Senseible does not reply to the buyer for you.

- [Whose tonne is it? One tonne, two footprints](https://senseible.earth/answers/supplier-scope-1-double-counted-in-scope-3)
- [My buyer asks for my Scope 3](https://senseible.earth/answers/buyer-asks-for-my-scope-3)
- [What exactly a buyer's supplier questionnaire asks](https://senseible.earth/answers/supplier-questionnaire-what-buyer-asks)
- [Is the GHG Protocol a law?](https://senseible.earth/answers/is-the-ghg-protocol-a-law)
- [Get my free carbon number](https://senseible.earth/msme-carbon-number)

Sources: [GHG Protocol Corporate Value Chain (Scope 3) Standard (Chapter 5 and glossary)](https://ghgprotocol.org/corporate-value-chain-scope-3-standard), [GHG Protocol Corporate Accounting and Reporting Standard, revised edition (Chapter 4, scopes and double counting)](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-11-07. Quotes are from the GHG Protocol Scope 3 Standard (Chapter 1 and the Table 7.8 on collecting data from suppliers in Chapter 7). The restaurant comparison and the reading that your emissions sit in the buyer's Scope 3 are ours.