What Carbon Data Should I Send My Customer?
Customer Carbon Data Requests
"Send us your carbon data" can mean three quite different things. Your customer might want your organisation's overall footprint, structured Scope 3 supplier data for their own value-chain calculations, or the carbon footprint of a specific product you supply them. Sending the wrong one wastes your time and still leaves the request unanswered. This page helps you work out which one it is, then routes you to exactly what to prepare.
Which kind of carbon data does your customer need?
Read the request again before you start calculating anything. Look for whether it names a specific product, references "supplier data" or a Scope 3 programme, arrives as a structured form covering more than just emissions, or simply asks for "your carbon footprint" with no further detail. That wording usually tells you which of the four categories below applies.
1. Organisational footprint
The request simply asks for "your carbon footprint" or "your emissions" with no product or supplier-programme language. This is your whole-company Scope 1 and 2 total (and sometimes relevant Scope 3), not tied to a specific item you supply.
What to send for an organisational footprint →2. Supplier / Scope 3 data
The request mentions "supplier emissions," a CDP or EcoVadis survey, or your customer's own Scope 3 reporting. They need the emissions tied to your relationship with them, not necessarily your whole company footprint.
What to send for a Scope 3 request →3. Product-specific footprint
The request names a specific product, SKU or service and asks for its carbon footprint per unit — often for a product carbon footprint (PCF), EPD or lifecycle assessment. This is the most detailed and time-consuming of the four, so only prepare it if this is explicitly what's being asked for.
See the product footprint checklist below ↓4. Sustainability / ESG questionnaire
The request arrives as a structured form, portal or scorecard covering policies, targets and emissions together — not a single carbon figure on its own. Carbon data is only one part of what you need to complete.
What to send for a sustainability questionnaire →Not sure which applies? Other common request formats have their own dedicated guides: a tender or procurement carbon requirement, or a request that specifically needs traceable, audit-ready evidence behind the figures.
If your customer needs a product-specific footprint
This is the most detailed of the four data types, so use it only when the request explicitly names a product or asks for a per-unit figure. Your customer wants the carbon attributable to that specific product or service, so they can slot it into their own Scope 3 supply chain inventory — a functional unit (per product, per kg, per service delivery), a stated boundary, and enough methodology detail that they don't have to come back and ask.
Usually mandatory: the product carbon footprint in kg or tonnes CO2e per functional unit, the system boundary (cradle-to-gate, gate-to-gate, or cradle-to-grave), the reference year, and the calculation standard used. Usually optional but strengthens your response: a lifecycle-stage breakdown, third-party verification, and your reduction initiatives.
Immediate checklist: what to gather before you reply
A complete response covers each of these — missing any one usually triggers a follow-up question from the customer's sustainability team.
- Functional unit and footprint figure — CO2e per product, per kg, or per service delivery
- System boundary — cradle-to-gate, gate-to-gate, or cradle-to-grave, stated explicitly
- Methodology and standard — ISO 14067, GHG Protocol Product Standard, or PAS 2050, with the reference year
- Emission factors used — the specific database and version, e.g. current UK Government DEFRA conversion factors
- Data quality detail — the split between primary (measured) and secondary (industry-average) data
- Verification status — verified, in progress, or not yet obtained, stated clearly either way
Step-by-step: putting together your response
- 1. Confirm the functional unit and boundary. Agree with your customer whether they need cradle-to-gate or a fuller lifecycle view before you calculate anything.
- 2. Calculate the footprint. Apply your chosen standard (ISO 14067, GHG Protocol Product Standard, or PAS 2050) using current emission factors.
- 3. Break it down by lifecycle stage. Show raw materials, manufacturing, distribution, use phase and end-of-life where you can, so hotspots are visible.
- 4. State your data quality. Note the primary-versus-secondary data split and, if you can, an uncertainty range around the figure.
- 5. Add verification status. If verified, name the body and standard applied; if not, say so and give a timeline if one exists.
- 6. Include reduction context. Mention relevant targets or initiatives — this positions you as a strategic supplier, not just a data source.
- 7. Deliver in a usable format. A PDF summary plus a CSV of the underlying figures covers most customer systems without extra requests.
Common mistakes to avoid
- Defaulting to a product footprint when a broader figure was asked for — a detailed per-product calculation wastes time if the customer only wanted your organisational total.
- Sending a figure with no boundary — an unquantified "our product has low emissions" claim, or a number with no stated boundary, has no reportable value to your customer.
- Mixing units — always use CO2e in metric tonnes or kilograms, with the functional unit clearly stated; don't mix carbon (C) with carbon dioxide (CO2).
- Selective boundary setting — excluding significant sources (like air freight) without transparent justification creates compliance risk for your customer, not just you.
- Conflating offsets with reductions — report gross emissions separately from any offset purchases; your customer needs the gross figure for their supply chain accounting.
How GreenKPO removes the manual work
Whichever data type your customer needs — organisational, supplier or product-level — most of the effort goes into applying the right emission factors consistently, keeping the boundary and methodology documentation aligned with the figures, and formatting the output so your customer's system can actually use it. GreenKPO keeps your activity data and current UK emission factors in one place, so the same calculation approach applies every time a customer asks. It doesn't set your system boundary or verification strategy for you; it removes the calculation and formatting work behind the response, so putting one together is a matter of hours rather than days.
Common questions
- The request just says "send us your carbon data" — where do I start?
Ask the customer to clarify if you're not sure, or default to your organisational Scope 1 and 2 footprint — it's the most commonly requested baseline and rarely wrong to lead with. - Do I need third-party verification for every product footprint?
Not always. If verification is pending or you haven't obtained it, say so clearly and give a timeline if you have one — an honest "not yet verified" is better than an unclear claim. - What if I've only got secondary (industry-average) data?
That's a reasonable starting point — state the primary-versus-secondary split clearly so your customer can judge data quality, and improve the mix over time as you collect more primary data. - Which boundary should I use — cradle-to-gate or cradle-to-grave?
Ask your customer which they need for their Scope 3 category. Cradle-to-gate is more common for upstream supplier data; cradle-to-grave is used when the use-phase or disposal falls within their reporting. - What format should I deliver the data in?
A human-readable PDF summary alongside a machine-readable CSV covers most customer systems, including CDP Supply Chain and similar platforms.
Build your complete carbon response, once
Whichever data type your customer needs, get it calculated, documented and formatted for their system — ready to reuse the next time they ask.