Can a customer make carbon data a condition of the contract?

A customer can set its own conditions for who it buys from, and many now include carbon questions. Whether a particular clause binds you depends on your contract, so read it, and take advice if a term worries you. This post isn't legal advice.

Do I have to share commercially sensitive information?

Carbon figures rarely need to reveal anything sensitive. If a request asks for details such as supplier names, prices or margins, ask what the customer needs them for, and offer an alternative, such as an allocated emissions figure with the method.

What if a customer wants a specific certification or platform?

Ask whether it is required or preferred, and whether an equivalent is accepted. If it costs money, ask whether it is needed for this contract and say what you can provide now, such as a published Carbon Reduction Plan.

Why does my customer want emissions for their account only?

Because your emissions are part of their Scope 3. A share allocated by revenue or another clear measure lets them include you without double counting the rest of your business.

What large customers can and can't reasonably ask of small suppliers

A large customer can reasonably ask a small supplier for its Scope 1 and 2 emissions, the method behind them, a reduction plan or commitment, and an allocated share of emissions for its account. Asks that go further, such as detailed product footprints at short notice, paid certifications or commercially sensitive data, are worth questioning politely: say what you can provide, by when, and why.

Updated 6 October 2026 by the Carbon Recycling team. Figures use the official UK government conversion factors and are checked against the current gov.uk guidance.

Why the requests are growing

Your emissions are part of your customer's Scope 3. When a large business measures its value chain, sets a science-based target or reports under rules such as the new UK Sustainability Reporting Standards, it needs figures from its suppliers. Public sector buyers ask for Carbon Reduction Plans under PPN 006, and the NHS asks every supplier for a net zero commitment or plan. So the requests come in tenders, onboarding forms and emails, and they vary a lot in what they ask.

Most are reasonable. Some ask for more than a small business can sensibly give. This post helps you tell the difference and respond well. It's practical guidance, not legal advice: what you are bound to provide depends on your contract.

Reasonable asks

These are standard, and a small business should expect to provide them within a few months of first being asked:

Scope 1 and Scope 2 emissions in tonnes of CO2e for a stated 12-month period.
The method: GHG Protocol, the UK government conversion factor year, and whether Scope 2 is location-based or market-based.
A net zero commitment or Carbon Reduction Plan, published so you can answer with a link.
The main Scope 3 categories you have measured, and which you haven't yet.
An allocated share of your emissions for the customer's account, by revenue or another clear measure, with the method stated.
Your reduction actions, with dates.
Annual updates using the same period and method.

Asks that may go too far

These are not necessarily unreasonable, but they deserve a conversation before you commit time or money:

The ask	Why to question it	A fair response
Full Scope 3 across all 15 categories, within weeks	Categories such as purchased goods take time and data a small firm may not have	Provide Scope 1, 2 and the main categories now, and a date for the rest
Footprints for every product you sell	Product footprints are a separate, larger exercise	Offer an allocation of your business footprint, and ask which products matter most
A specific paid certification or rating	It may cost more than the contract is worth to you	Ask if it is required or preferred, and whether your published plan is accepted instead
Your suppliers' names, prices or margins	Commercially sensitive, and rarely needed for carbon figures	Offer emissions totals and the method instead
Targets set to the customer's own timetable	Your target should be one you can deliver	Share your own target and plan, and explain how it supports theirs
Calling your target "science-based"	Only the SBTi can validate that	Describe your target accurately

How to respond

Find out what they actually need. A questionnaire is often a standard form sent to every supplier. The person behind it may only need your Scope 1 and 2 total and a plan link.
Answer what you can, fully and on time. Partial, honest answers build more trust than a late, perfect one. Our post on answering a customer carbon questionnaire has model wording.
Say what's missing and when it will come. A date turns a gap into a plan.
Explain what's proportionate for your size, politely and in writing, if an ask goes beyond that.
Ask about support. It costs nothing to ask whether the customer has a template, guidance or a preferred method it can share.
Check your contract if the request is presented as a requirement, and take advice if a clause worries you.

Don't refuse outright

Pushing back on an unreasonable ask is fine. Refusing all carbon questions usually isn't wise. Buyers increasingly score suppliers on this, and the NHS has said that from 2030 it will only buy from suppliers that meet or exceed its net zero commitments. A small business with a published Carbon Reduction Plan and a year of figures can answer most requests in minutes, which is far easier than negotiating each one. Our guide on what to send when a customer asks for your carbon emissions explains the data side, including how to allocate your emissions to one customer.

The same logic, in reverse

If you ask your own suppliers for data, apply the same test. Ask the few that make up most of your spend for their Scope 1 and 2 totals, the period, the method and their revenue, and leave the rest until you need it.

How Carbon Recycling helps

Carbon Recycling keeps your footprint, Carbon Reduction Plan and SECR figures in one place, so you can answer any customer quickly and consistently. On the Growth and Enterprise plans you can also send your own suppliers a secure link to report their emissions, with no account needed on their side, and record their answers against the right Scope 3 category.