How to Send a Supplier Emissions Data Request

A request for a product carbon footprint often comes back with a company-wide estimate, a sustainability report or a number with no production site attached. None tells you what happened at the plant that made your goods.

A usable supplier emissions data request must identify the plant, product and production period, then connect the emissions figure to production records. This guide sets out the fields to request and a standard response format.

Start with the plant that made the goods

Send the request to your commercial contact, but ask for the response to be completed by someone with access to plant production and energy records. This may be the plant manager, environmental team, energy manager or production accountant.

Ask which physical plant made the goods on each shipment. Record its legal name, trading name, full address and country. If several plants can make the same product, require the supplier to identify the plant used rather than providing a group average.

The production route must also belong to that plant. Steel made from iron ore, coke and a blast furnace has different inputs from steel made by melting scrap or direct reduced iron in an electric arc furnace. A supplier name and product description alone cannot distinguish those routes.

HMRC and HM Treasury's CBAM policy summary on gov.uk says UK CBAM starts on 1 January 2027 and covers aluminium, cement, fertilisers, hydrogen, and iron and steel. Importers of goods in those sectors should build the plant link into purchasing and shipment records now.

Identify the product, plant and production period

Use identifiers that procurement, logistics and the plant can all recognise. Ask for your purchase order or contract reference, the supplier's product code, the product description and the relevant commodity code. Include grade, specification or composition where those details distinguish one production route from another.

Define the production period with start and end dates. Ask whether the figure covers the batch that supplied your order, a production campaign or all output from the plant during that period. The response should state which basis was used rather than leaving you to infer it.

Request the quantity made during the stated period and the quantity supplied to you. Record both in a named physical unit. This gives you a denominator for the emissions intensity and a separate quantity to connect with your imports.

Request the emissions figure in a consistent form

Ask for total embedded emissions and emissions per tonne of product. Require the supplier to state the emissions unit, product unit, calculation boundary and whether the result contains direct emissions, indirect electricity emissions or both.

Do not accept a bare number. Ask for the calculation method, the person or organisation that prepared it, the preparation date and any verification status. Verification status should be a factual response such as not verified, internally reviewed or externally verified, with the verifier named where applicable.

If a plant makes several products, ask how shared fuel, electricity and process emissions were allocated. Record the allocation basis in words, such as product mass, production time or direct measurement. This lets you see whether two supplier figures were prepared on comparable terms.

Ask for the production route, inputs, fuel and power data

For cement, ask whether the plant makes clinker or only grinds bought-in clinker. At a clinker plant, limestone releases process CO₂ when heated and the kiln burns fuel. Request clinker output, cement output, clinker consumed, raw-meal chemistry, fuel types and quantities, calorific values, carbon content and electricity per tonne.

Where a cement plant uses alternative fuels, request the quantity and biomass fraction, together with how that fraction was determined. Where it buys clinker, request the clinker supplier's embedded emissions per tonne. Also record slag or fly ash quantities because these materials can replace clinker in blended cement.

For steel, begin with the route. A blast furnace and basic oxygen furnace route needs hot-metal output, coal and coke use, reductant rates, limestone and dolomite quantities, and the shares of pig iron and scrap. An electric arc furnace response should give output, scrap, direct reduced iron and pig iron inputs, electricity use and the electricity source.

Ask for embedded emissions per tonne of bought-in precursors such as pellets, direct reduced iron, hot briquetted iron, pig iron and ferro-alloys. For electricity, record whether it came from the grid or a captive plant. For grid power, ask for the grid country. For a captive plant, request its fuel and efficiency data.

Use one response table for every supplier

Put the fields in a spreadsheet or portal rather than asking an open question by email. Keep one row structure across suppliers and allow supporting files to be attached against the relevant field.

Ask the supplier to mark unavailable fields explicitly. A blank cell is ambiguous. It might mean zero, not applicable, not measured or not disclosed.

What if the supplier cannot provide actual data?

HMRC and HM Treasury's CBAM policy summary says UK importers can report actual embedded emissions for CBAM goods or use government default values. Default values are set by government and are not specific to the supplier's plant. Lower real emissions can only be recognised when the supplier reports its own data.

If actual data is unavailable, record that answer rather than substituting an unsupported estimate. Ask which fields the plant can provide now, who owns the missing records and when the next complete production period will close. Start with plant identity, route, output, main inputs, fuel and electricity because these establish the structure for a later calculation.

Do not replace a plant response with a supplier's corporate footprint. Keep the default-value route separate from the actual-data route in your records, and retain the supplier correspondence that explains why actual data was unavailable.

CarbonMeter's CBAM readiness pilots map imports to the plants that made them and collect those suppliers' real embedded emissions.

What to do this quarter

• List imported products and the suppliers that provide them.
• Add a field for the plant that made each product.
• Send the same response table to every relevant supplier.
• Review answers for missing periods, units, routes and evidence.
• Separate actual plant data from government default values in your records.