What a CDP supply chain request is
CDP runs a global disclosure system for environmental data. Large companies that are CDP Supply Chain members use it to ask their suppliers for climate information, because your emissions are part of their Scope 3. The request shows in the CDP Portal, where you register, set up your questionnaire and answer.
Answering isn't a legal requirement, but the customer asked because they need the data for their own reporting, so treat it like any other customer request with a deadline.
The practical rules for a small supplier
| Question | Answer |
|---|---|
| Which questionnaire? | The SME questionnaire, if eligible. CDP's 2024 overview recommends it below 500 employees and US$50 million revenue, and allows it up to 1,000 employees and US$250 million. It has no sector-specific questions. |
| Is there a fee? | Organisations requested only by Supply Chain members are generally exempt from CDP's admin fee. If you're exempt, you select "No fee payable" before submitting. |
| One response or several? | One integrated response goes to all your requesters. You can't answer them separately. |
| Deadlines (2026) | Scoring deadline 16 September. Final disclosure deadline in the week of 26 October; responses after 16 September are not scored. |
| Public or private? | Your choice at submission. Requesting customers see your response either way, but only a public response can score A or A-. |
| Who submits? | Only the person who takes the "Submission Lead" role in your portal. Sort this out early. |
The questions that matter most
- Scope 1 and Scope 2 emissions for a stated 12-month period, in tonnes CO2e, with Scope 2 location-based and, if you're on a renewable tariff, market-based too. See our post on location-based vs market-based.
- Scope 3, at least the categories you've measured. Saying which you've left out and when you'll add them is better than leaving it blank.
- Targets, with a baseline year, a percentage and a target year. Only call a target science-based if the Science Based Targets initiative has validated it.
- Emissions allocated to your customers. When a CDP Supply Chain member has requested you, CDP lists a question in the SME questionnaire (20.12) as mandatory for submission. It asks for your emissions allocated to the customers who requested you.
A worked example: allocating to one customer
A supplier uses 40,000 kWh of electricity, 70,000 kWh of gas and 6,000 litres of van diesel in a year. With the 2026 government factors that's 28.26 tonnes of Scope 1 and 5.24 tonnes of Scope 2. The requesting customer spent £300,000 out of a turnover of £2,500,000, which is 12%.
- (28.26 + 5.24) × 12% = 4.02 tonnes CO2e allocated to that customer.
State the method: "allocated by share of revenue". It's an estimate, but it's honest and repeatable. If one product line is much more carbon-intensive than another, allocate by units, weight or hours instead and say so.
If you haven't measured yet
Don't skip the response. Answer what you can, say you're measuring and give a date. Most small firms can produce a first Scope 1 and 2 footprint from a year of energy bills and fuel records in a few weeks, which is enough to answer properly next cycle. Our guide on what to send when a customer asks for your carbon data covers the general approach, and EcoVadis carbon questions covers the other platform customers use most.
How Carbon Recycling helps
Carbon Recycling turns your bills, fuel, travel and waste records into Scope 1, 2 and 3 figures with the right year's UK government factors, ready to type into CDP. Our free supplier questionnaire answer bank drafts consistent answers from your figures, including the revenue-share allocation for one customer, so the number you give CDP matches what you put in tenders and on your website. And once each customer's share is visible, it's easier to agree the reductions that matter to them: in this example, every tonne you cut from your own Scope 1 and 2 takes 12% of a tonne off the figure you report to that customer.