What your customer expects when they ask for your product's carbon footprint

More and more industrial customers and retail chains ask their suppliers for the carbon footprint of what they buy. They usually need it to measure their own Scope 3 or to answer a tender. The request arrives by email, with a short deadline and rarely with clear instructions.

What exactly does your customer want to see?

Behind the request there are four questions. Answering them upfront saves back-and-forth:

1. How much? A value in kgCO₂e per unit of product, with a clearly defined functional unit.
2. How far does the calculation go? The system boundary. The usual one is cradle to gate: raw materials, inbound transport and manufacturing at your plant.
3. Under which standard? A recognised reference such as ISO 14067, which sets how it is calculated and what is included.
4. How can it be checked? Who verified the calculation and with which identifier it can be looked up.

A sentence like “we work sustainably” answers none of the four.

Why does a spend-based estimate usually fall short?

Because your customer will use the figure to decide and to report. A spend-based calculation multiplies the amount of a purchase by a sector average, so the footprint moves with price and not with the product. If you invest in a cleaner process and your price goes up, the spend-based calculation penalises you. We explain it in more detail in why spend-based penalises decarbonisation and in the comparison of physical vs spend-based factors.

What do you need to reply?

You do not need an implementation project. A physical calculation starts from what the product is, and that is already documented in your company:

• Drawings and technical data sheets.
• The bill of materials and weights.
• Manufacturing processes and, if you have them, energy consumption.
• Where the materials come from and the inbound transport mode.

When the documentation is unclear, the most conservative factor is applied and noted, so the result is defensible and can be improved later with primary data.

Who should be involved inside your company?

The request usually lands with sales or management. Quality and product engineering gather the documentation; sustainability reviews the breakdown and decides whether it is worth improving the figure with plant measurements. Name one person as the contact from day one, so the customer does not receive three different answers.

How long does it take?

It depends on the product and the documentation available. With Xain, the calculation takes 2 to 3 hours and the verified certificate is delivered in 2 to 3 business days. That fits most tenders, as long as you start early and have the documentation at hand.

What should you hand over with the number?

The certificate, the calculation breakdown and a note with the assumptions. That way your customer can reuse the figure in their inventory and, if something changes, knows which part to review. If you also need it per reference or per shipment, see the per-shipment certificate.

What mistakes come up again and again?

• Replying with a sector average. Your customer wants the figure for your product, not for a category.
• Giving a number with no boundary or standard. Without knowing where the calculation stops or which method was used, the customer cannot put it in their inventory.
• Waiting until the last day. Gathering drawings, bills of materials and transport data takes longer than it seems.
• Answering in prose instead of a document. A certificate with an identifier can be filed, cited and checked; an email cannot.
• Having three different people answer. Each version of the figure raises doubts about the others.

How do you reply, step by step?

1. Receive and scopeAgree with your customer the unit, the boundary and the standard they expect.
2. Gather documentationDrawings, data sheets, bill of materials, weights and processes.
3. Calculate and certifyWith physical factors and a recognised method, fully traceable.
4. Reply with the certificateValue, boundary, standard and registration number in a single message.

Checklist before you reply

• The functional unit is defined (per part, per kilo, per shipment).
• The calculation boundary is clear and matches what your customer asks for.
• You know which standard was used and who verifies it.
• You have the breakdown and a note with the assumptions.
• There is one point of contact and a review date for the figure.

How does Xain solve it?

Xain calculates the product footprint under ISO 14067 from the technical documentation you already have, without relying on your suppliers filling anything in. The calculation follows a process tree: each node carries a physical factor and, when something is ambiguous, the most conservative one is applied. If you later provide primary data, it replaces the generic data. The result is a certificate with a unique registration number and traceability down to the factor of each node, and the methodology is verified by LRQA.

If you have an open request, write to us with the deadline and what you already have at hand.