Catena-X Product Carbon Footprints: What Automotive Suppliers Need to Know

Catena-X is an automotive industry initiative building a shared way for companies across the supply chain to exchange data — and Product Carbon Footprints are one of its core use cases.

For a supplier, the practical question is narrower than the initiative itself: what will my customers actually ask me for, and what should I have ready?

This guide covers what Catena-X is trying to solve, why PCF is central to it, and what a supplier should do now — which is mostly not "join a data space."

What Catena-X Is

Catena-X is a collaborative automotive data ecosystem involving OEMs, suppliers, and technology providers. Its purpose is to let companies exchange data across the supply chain without each pair of companies building a bespoke integration, and without any participant surrendering control of its data.

It covers several use cases. Product Carbon Footprint is among the most developed, because it is a problem every participant shares and none can solve alone.

Catena-X describes its PCF work as a harmonized approach for calculating, exchanging, and verifying supplier-specific Product Carbon Footprints across the automotive supply chain, with emphasis on increasing the share of supplier-specific primary data over time. Catena-X: Product Carbon Footprint

Why PCF Is a Core Use Case

Consider what happens today when an OEM wants the carbon footprint of a vehicle.

It asks its Tier 1 suppliers. Each Tier 1 asks its Tier 2 suppliers. Each Tier 2 asks Tier 3. At every level:

• The request arrives in a different format
• Different methodologies and boundaries are used
• The same supplier answers the same question several times for several customers
• Numbers are recalculated rather than reused
• A carefully produced Tier 3 figure rarely survives to the OEM intact

The result is enormous duplicated effort producing data that is not comparable between suppliers — which defeats the purpose, because comparability is the whole point of asking.

Catena-X addresses this by standardizing two things together: how the footprint is calculated, and how it is exchanged. Standardizing only one would not work. Consistent data in incompatible formats is as unusable as inconsistent data in a common format.

Supplier-Specific Primary Data

The stated direction is toward primary data — footprints based on what a specific supplier actually did, rather than industry averages.

This matters because of a structural weakness in average-based data: two suppliers producing the same part with very different energy sources and efficiencies show the same calculated footprint if both are represented by the same industry average. That makes it impossible to reward a supplier that improves, or to choose between suppliers on carbon.

Primary data fixes that, but it can only come from the supplier. Which is why the framework has to reach all the way down the chain rather than stopping at Tier 1.

See Scope 3 supplier data for the buyer's side of this.

PCF Calculation Rules

The reason a shared methodology is necessary becomes obvious once you look at where two competent analysts can legitimately differ on the same part:

• Boundary — what is in and out
• Declared unit — per part, per kilogram, per thousand
• Energy allocation — how facility energy is assigned to a specific part
• Scrap treatment — cut-off or avoided burden
• Emissions factor sources — which database, which version
• Co-product allocation — mass, economic value, or physical relationship
• Electricity accounting — location-based or market-based

Each of these is a defensible choice. Made differently by two suppliers, they produce numbers that cannot be compared — and a buyer who compares them anyway reaches a wrong conclusion.

A shared rule set removes that ambiguity. For suppliers, the practical implication is that a PCF may need to be recalculated against a customer's specified methodology rather than your own preferred one, so the underlying data needs to be held in a form that supports recalculation. See cradle-to-gate carbon footprints.

Data Quality Requirements

Alongside the number, the framework emphasizes describing its quality — particularly how much rests on primary data rather than estimates.

For suppliers this means tracking, per input, whether a figure is measured, supplier-provided, calculated from activity data, or estimated from averages. The primary-data share becomes a reported attribute rather than an internal note.

This is worth building into your method from the first PCF. Retrofitting data-quality labelling onto a completed spreadsheet is considerably harder than recording it as you go.

Digital PCF Exchange

The exchange side is what distinguishes this from a methodology document.

The intent is that a PCF calculated once can move between companies in a machine-readable, consistent form — so a Tier 2 supplier can incorporate its Tier 3 supplier's footprint directly, rather than re-requesting it in a bespoke spreadsheet and re-keying it.

Two principles shape the design. Data stays under the control of the company that produced it rather than being pooled centrally. And interoperability is built on shared standards rather than a single platform every participant must adopt.

Whether a given supplier ends up connecting directly, through a service provider, or through a customer's system is an implementation question. The underlying expectation — a calculated, documented, supplier-specific PCF per part — is the same regardless.

OEM to Tier 1 to Tier 2 to Tier 3

The intended pattern is compounding rather than re-requesting:

• A Tier 3 supplier calculates the footprint of the material or component it ships
• A Tier 2 supplier incorporates that figure into its own component footprint, adding its processing and freight
• A Tier 1 supplier incorporates that into a system or module footprint
• The OEM aggregates to a vehicle footprint

Each tier adds only what it actually did. Nobody recalculates what somebody upstream already calculated.

The dependency this creates is worth being clear-eyed about: the chain only works if the deepest tiers participate. A Tier 2 supplier cannot produce a primary-data footprint if its own suppliers provide nothing. This is why pressure is reaching smaller suppliers, and why it will keep reaching further. See automotive supplier sustainability.

Interoperability

One of the more useful aspects for suppliers is the emphasis on not requiring everyone to use the same software.

A supplier should be able to calculate a PCF in whatever system suits its operations and still exchange it with customers using different systems. The standard governs the data and the method, not the tooling.

The practical criterion when evaluating software: can it export a PCF with the full set of attributes — boundary, declared unit, period, data quality, primary-data share, methodology — rather than only a number? A tool that produces a figure but cannot describe it will not be usable in a standardized exchange.

What SMB Suppliers Should Prepare For

The honest answer for most small and mid-sized suppliers: not a data-space integration, at least not first.

What to do now:

• Be able to calculate a PCF at all. This is the actual gate. Standardized exchange of a number you cannot produce is irrelevant.
• Hold the inputs, not just the output. BOM, masses, factors, allocation rules, freight. If a customer specifies a different methodology, you need to recalculate, not re-research.
• Track data quality per input from the start.
• Document methodology as a standing artifact rather than per request.
• Ask your customers what they expect and when. Requirements vary by customer and change; your customer's supplier development contact will tell you.
• Get your own suppliers started. Your primary-data share depends on them, and they will need lead time.

The expectation typically arrives before the infrastructure does. Suppliers who can produce a documented, well-structured PCF will be in a reasonable position regardless of how the exchange mechanics settle.

Software Requirements

What to look for, given all of the above:

• BOM-based calculation, not a single-number calculator
• Configurable boundaries and allocation rules
• A maintained emissions factor library with versioning
• Per-input data quality tracking and primary-data share
• Recalculation when a factor or supplier value changes, across all affected parts
• Export with full metadata, not just a figure
• Somewhere to store supplier-provided PCFs and their attributes

See PCF software for automotive suppliers for a fuller evaluation, and IMDS and PCFs for the material-data side.

How Aclymate Helps

• Product Footprint Pack — BOM-based PCFs that retain inputs, factors, and allocation rules so they can be recalculated against a customer's methodology
• PCF services — expert calculation and review
• Supplier & Scope 3 Data Support — for raising the primary-data share by getting your own suppliers producing footprints
• Supply chain sustainability consultants — for interpreting what a specific customer requires

See the Automotive & Transportation page, or automotive Scope 3 emissions for the wider context.