CBAM quarterly reports 2023–2025 — did you file all 9 transitional periods?

Short version. The CBAM transitional period required 9 quarterly reports between October 2023 and January 2026. The penalty for missing one is €10–50 per tonne of unreported CO₂e emissions per Article 28 of Regulation (EU) 2023/956, indexed to the HICP. Many importers — and their advisors — missed one or more. Late filing now, before NCA discovery, dramatically reduces the per-tonne penalty.

The 9 transitional-period reporting periods

Quarterly reports cover imports of CBAM goods (cement, iron and steel, aluminium, fertilisers, hydrogen, electricity in some MS) into the EU. They were submitted to the CBAM Transitional Registry — a separate portal from the definitive-period CBAM Registry that launched 1 January 2026.

You can quickly run through your filing history with our CBAM quarterly-report compliance checker — 9 yes/no questions, surfaces penalty exposure with the regulation citation. No data stored.

The penalty under Article 28

The transitional-period penalty for missing or incomplete reports is €10–50 per tonne of unreported CO₂e emissions. The range matters:

• Lower end (€10–15/t) — applied when the importer self-corrects voluntarily, the omission was negligent (not deliberate), and the magnitude is small (one or two quarters missed, modest tonnages).
• Middle (€20–35/t) — typical NCA-discovered non-compliance for an importer who claims they didn't know about the obligation.
• Upper end (€40–50/t) — repeat or systematic non-compliance, deliberate avoidance, large tonnages.

The figure is HICP-indexed since 2024 — the actual per-tonne penalty you'll see assessed today is roughly 5–8% above the nominal range. For our calculations below we'll use the nominal €10–50/t for clarity.

Worked example

A German importer, "Acme GmbH", imported 100 tonnes of hot-rolled steel coils (CN 7208) from Turkey in each of three transitional quarters (Q2 2024, Q3 2024, Q4 2024). They failed to file any of those three reports. The default-value direct emissions intensity for Turkey × CN 7208 is approximately 1.7 tCO₂e per tonne of product (per Implementing Reg (EU) 2025/2621).

Penalty exposure:

• Unreported emissions: 3 quarters × 100 t × 1.7 tCO₂e/t = 510 tCO₂e
• Lower-bound penalty: 510 × €10 = €5 100
• Upper-bound penalty: 510 × €50 = €25 500
• With HICP indexing (2026 ≈ 1.07× nominal): the assessed range is roughly €5 460 – €27 285.

For Acme to land at the lower bound, they self-disclose now via their NCA (Deutsche Emissionshandelsstelle, DEHSt), file the three retro reports, pay the assessed penalty, and move on. To land at the upper bound, they wait for DEHSt to discover the gap during a routine audit — likely 2027–2028 — and the magnitude works against them.

How to retrofit a late report

1. Pull the import data. You need: per-shipment CN code, country of origin, tonnage, and ideally the verified emissions intensity from the supplier (otherwise default values apply).
2. Identify your NCA. Country-of-establishment determines the NCA, not country-of-import. A German importer goes via DEHSt regardless of where the goods landed in the EU. Use the scope checker with your ISO-2 country for the NCA contact.
3. Contact the NCA proactively. Send a written self-disclosure email to the NCA's CBAM team listing the missed quarters. Most NCAs assign a case officer who walks you through the late-filing portal access.
4. File via the Transitional Registry. The portal still accepts retro filings as of 2026. Submit per the standard quarterly-report format with the actual import data.
5. Negotiate the penalty assessment. Once the NCA issues a draft penalty notice, you have a 30-day window to provide mitigating evidence (no prior compliance issues, no deliberate avoidance, etc.). Most importers find the lower-bound applies after this step.

What triggers an audit

• Customs data mismatch. NCAs cross-reference EU customs records against the CBAM Transitional Registry. If a CN-code import shows up at customs but no quarterly report mentions it, that's a flag.
• Missed annual declaration. The first annual declaration (due 31 May 2027) requires reconciliation with prior quarterly data. Importers showing 2026 imports but no transitional history will be queried.
• Industry tip-off. NCAs receive a non-trivial number of compliance reports from competitors. If you're a non-filer in a sector where most peers filed, expect to be looked at.

What to file now (or pass to your client)

Step 1: run the CBAM quarterly-report compliance checker on /cbam — it lists all 9 periods, you tick which were filed, and surfaces the penalty exposure range with the regulation citation.

Step 2: for any quarter you ticked "didn't file", pull the import data for that period. The CBAM calculator handles one shipment at a time; for retro batches across 2023–2025 we offer per-row processing under enterprise — get in touch via the contact form if you have more than ~50 shipments to size in one go.

Step 3: contact your NCA. The contact details are on the same scope checker output. Some NCAs (DEHSt, France's DGEC) accept email self-disclosure; others require a portal account first.

Sources

• Regulation (EU) 2023/956 — establishing CBAM, Article 28 (penalty regime). Source URL: eur-lex.europa.eu/eli/reg/2023/956/oj/eng.
• Implementing Regulation (EU) 2023/1773 — transitional-period reporting requirements. The 9-quarter framework and the report format come from this regulation.
• Implementing Regulation (EU) 2025/2621 — default emissions values. Source URL: eur-lex.europa.eu/legal-content/EN/TXT/?uri=OJ:L_202502621.
• Updated National Competent Authorities list (5 January 2026): EU Commission NCA PDF.

FAQ

Related

• I missed the 31 March 2026 CBAM authorisation deadline — what now?
• EU CBAM in 2026 — the complete guide for customs brokers and freight forwarders