Why your supplier’s precursor number is usually not usable

Published 14 September 2026

If you make steel from bought pig iron, cement from bought clinker, urea from bought ammonia or aluminium products from bought unwrought aluminium, the emissions embedded in that input travel with your goods. The act calls the input a precursor: any input material into a production process that is itself in the list of CBAM goods (IR (EU) 2025/2547 Art. 1(7)).

A number from the supplier, on its own, is not enough. The rule is stricter than it looks, and it is the point at which a filing that set out to use actual data falls back to default values.

The two conditions, and there are only two

For a precursor produced outside your installation, in a third country that is not exempted from CBAM, actual data obtained from the operator of the installation producing the precursor shall be used only if both of the following are met (IR (EU) 2025/2547 Annex II point A.1(4)):

• (a) the data must be taken from a verification report issued by a verifier holding an accreditation in accordance with Article 18 of Delegated Regulation (EU) 2025/2551, valid at the time the report was issued and for the sectoral scope required for the aggregated goods category of that precursor; and
• (b) the verification report must cover the reporting period during which the precursor was produced.

Then the sentence that decides most cases: where the operator does not have a verification report meeting conditions (a) and (b), the relevant default values for the precursor shall be used (Annex II point A.1(5)).

The act leaves no third route. A supplier’s spreadsheet, a supplier’s own calculation, a certificate from a body that is not accredited for CBAM, a verification report for a different year, or a verification report from a verifier accredited for another sector: each fails one of the two conditions, and each sends the precursor to its default value.

What "usable" actually requires from your supplier

Read the two conditions as a checklist for the document you ask for:

• A verification report, not a data sheet. Condition (a) says the data must be taken from the report itself; a figure with no report behind it has nowhere to be taken from.
• An accredited verifier. A verifier is a legal person accredited by a national accreditation body for the purpose of the CBAM Regulation, under Delegated Regulation (EU) 2025/2551 (Art. 1(1) and Art. 3(1) of that act; the calculation act cross-refers to its Article 18).
• Valid when the report was issued. An accreditation that lapsed or had not yet been granted on the report’s date fails (a).
• The right sectoral scope. The scope of accreditation is defined as the CBAM activity groups in Annex I to Delegated Regulation (EU) 2025/2551 (Art. 1(3)); cement clinker and cement sit in one group, sintered ore, pig iron and direct reduced iron in another. A verifier accredited for one is not, by that fact, accredited for the other. The scope must match the aggregated goods category of the precursor.
• The right period. The report must cover the reporting period in which the precursor was produced, not merely the year in which you used it.

What you must record either way

Whether the precursor ends up on actual or default values, the monitoring rules ask the same questions about it (Annex II point E(2)): the country of origin; the installation where it was produced, identified by its identifier, UN/LOCODE, address and coordinates; whether it originates in a non-exempted third country; the production route; the specific parameters that determine its embedded emissions; its specific embedded direct and indirect emissions as an average over the most recent available reporting period; the start and end date of that reporting period; and the quantity of the precursor used in each production process.

Your Operator’s Emissions Report then lists each precursor twice over: those on default values, with the CN code, name, country of origin where known and the default value applied; and those on actual values, with the reporting period, the year of use and the specific embedded emissions (IR (EU) 2025/2547 Annex IV point 1.1, items 22 and 23; the same two lists are carried into the Operator’s Summary Emissions Report, point 1.2, items (12) and (13)).

Two cases that are simpler than they look

• A precursor from the EU or from an exempted country or territory is counted at zero embedded emissions (Annex III point B, the rule under the complex-goods formula, and Annex II point E(2)(h)). The two conditions above apply only to precursors from non-exempted third countries.
• A precursor you make yourself in the same installation, not sold or transferred out, may be monitored jointly with the complex good as one production process (Art. 4(9)). The two conditions above are about precursors bought in from another installation.

Why this is where filings collapse

A default value is set at the average emission intensity of the exporting country for that good, increased by a mark-up (Regulation (EU) 2023/956 Annex IV point 4.1), and the values are published per country and per CN code. In our reading, an average with a mark-up on top will usually sit above an actual value taken from a verification report for a specific installation; that is a product reading, not a rule. A producer who has actual values for their own process emissions but cannot meet (a) and (b) for a bought-in precursor keeps the default for that precursor, and the total embedded emissions of the finished good carry it.

The fix is upstream: ask the supplier for the verification report, check the accreditation scope and the period on its face, and keep the report with your own records so your verifier can see it. Recital 18 of IR (EU) 2025/2547 expects exactly that: where the report includes actual embedded emissions of precursors not produced at the installation, the operator should also provide the verifier with the verification report of the producing installation.

Regulatory sources: Implementing Regulation (EU) 2025/2547, Art. 1(7), Art. 4(9), recital 18, Annex II points A.1(4), A.1(5) and E(2), Annex III point B, Annex IV points 1.1 and 1.2; Delegated Regulation (EU) 2025/2551, Art. 1(1), Art. 1(3), Art. 3(1), Annex I; Regulation (EU) 2023/956 Annex IV point 4.1.