As the EU’s Carbon Border Adjustment Mechanism (CBAM) moves through its final transitional year, 2025 brings a clear priority for importers of carbon-intensive goods: get your CBAM reporting in order.

While purchasing CBAM certificates isn’t required until 2026, your ability to report accurately now will directly impact your readiness, costs, and compliance next year. Poor data quality practices in 2025 could lead to reporting mistakes, business disruption, and enforcement risks once the financial obligations begin.

There’s still time to prepare, but it takes coordination across sustainability, procurement, and finance teams. Here’s what mid-market enterprises need to know about CBAM’s reporting requirements, and where to start.

What is CBAM and why does it matter?

CBAM puts a carbon price on specific imported goods, ensuring emissions carry a cost no matter where production happens. It’s the EU’s response to carbon leakage: when companies move carbon-heavy production abroad or import high-emission goods to avoid EU climate costs.

It’s also a core part of the Fit for 55 package, aimed at cutting EU greenhouse gas (GHG) emissions by 55% by 2030, and it supports the broader goals of the European Green Deal, Europe’s plan to become the first climate-neutral continent by 2050.

CBAM currently covers:

• Iron and steel
• Cement
• Aluminium
• Fertilisers
• Electricity
• Hydrogen

If your company imports these goods into the EU, you must register as a CBAM declarant, submit emissions reports, and buy CBAM certificates from 2026 onward.

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CBAM reporting phases 

To help businesses adjust, CBAM is being introduced in phases. This approach gives companies time to build internal systems, adapt to reporting requirements, and allows the European Commission to refine the framework before full financial enforcement begins.

Transitional phase (1 October 2023 – 31 December 2025)
Reporting only. At the end of 2025, the European Commission will also review CBAM’s progress and consider expanding its scope before full enforcement begins.

Definitive phase (from 1 January 2026 onward)
Reporting continues, with certificate purchasing and annual surrender.

2026–2030
Financial obligations will increase as free EU allowances are phased out. The scope may expand to cover products like chemicals, polymers, or glass by 2027–2028.‍

By 2034

The phase-out of free allowances will be complete. EU producers and importers will fully pay for embedded emissions, aligning CBAM with Europe’s climate targets.

CBAM reporting requirements in 2025: What’s required during the transitional period?

2025 is the final year of the reporting-only phase. It’s your last chance to test and refine reporting systems before financial enforcement begins. No payments are required yet, but reports must be accurate, submitted on time, and based on the EU’s official calculation methodology.

Quarterly reports are due one month after the end of each quarter:

• Q1 2025: due by 30 April 2025
• Q2 2025: due by 31 July 2025
• Q3 2025: due by 31 October 2025
• Q4 2025: due by 31 January 2026

What to include in a CBAM report

Importers of CBAM-covered goods must submit their quarterly emissions report through the CBAM Transitional Registry.

These reports must include:

• Type and quantity of imported goods: Specify the goods using their Combined Nomenclature (CN) codes and state the quantity imported.
• Embedded emissions:
  
  • Direct emissions: Greenhouse gas emissions directly associated with the production processes of the imported goods.
  • Indirect emissions: Emissions resulting from the electricity consumed during production, applicable to specific sectors such as cement and fertilizers.
• Production details:
  
  • Country of origin: The country where the goods were produced.
  • Production facility: Name and address of the installation where the goods were manufactured.
  • Production processes: Detailed description of the manufacturing processes used.
  • Precursors: Information on any precursor materials used in the production of the final goods.
• Carbon pricing: Details of any carbon price paid in the country of origin, including the type of carbon pricing mechanism and the amount paid (if applicable).

To help with the collection of this detailed information, the European Commission has provided the CBAM Communication Template for Installations. This template is designed to help importers gather necessary data from their non-EU suppliers, ensuring consistency and compliance with CBAM reporting requirements.

Why data quality matters

The emissions data you report from 2026 onwards will directly affect how many CBAM certificates you'll need to purchase, and how much those will cost. 2025 is the final window to get your internal systems and supplier relationships in order before costs rise and enforcement tightens.

Incomplete or incorrect reports can lead to penalties of €10 to €50 per tonne of unreported emissions in 2025 and €100 per excess tonne in 2026, adding up quickly for high-volume importers. And without reliable data from suppliers, you risk delays in reporting and potential compliance issues that could affect your ability to import.

How to submit your CBAM report: Understanding the Transitional Registry

All CBAM reports must be submitted via the CBAM Transitional Registry, the EU’s online platform for managing emissions reporting. Here’s how to get started:

1. Create an EU Login account

2. Ensure your company has an EORI number

3. Contact your National Competent Authority (NCA)

They’ll guide you on:

• Verifying your company info
• Assigning user roles in the Uniform User Management & Digital Signature (UUM&DS) system
• Activating your access to the CBAM Declarant Portal

4. Login and submit reports through the CBAM Declarant Portal

Once approved, log into the Declarant Portal via UUM&DS. From the menu, navigate to "CBAM TR" to submit your quarterly CBAM reports. You’ll input emissions data, production information, country of origin, and any carbon price paid at source, then submit it directly through the system.

Important: If your company falls below the proposed 50-tonne exemption, you still need to report until that exemption is formally adopted.

What happens in 2026?

From 1 January 2026, CBAM enters its definitive phase. This means:

• Reports shift from quarterly to annual.
• The first verified annual report for 2026 is due by 31 May 2027.
• Importers must purchase and surrender CBAM certificates based on reported emissions.
• Stricter third-party data verification and audit requirements apply.

The current CBAM Transitional Registry will transition to the CBAM Registry for the definitive phase. This platform will manage emissions reporting and certificate transactions. Only authorized CBAM declarants will be permitted to import CBAM goods. 

Applications to become an authorized CBAM declarant opened on 31 March 2025. Once approved, importers will receive a CBAM account number and gain access to the CBAM Registry.​

Default values vs. actual emissions: What companies should know in 2025

As a general rule, importers must report actual embedded emissions using the EU’s official monitoring methodology. However, default values are allowed in specific cases during the transitional period (except for electricity) when actual data is unavailable.

Q4 2023 to Q2 2024:
Declarants could use European Commission default values without any quantitative limit.

From Q3 2024 to 31 December 2025:
Default or estimated values can only be used for complex goods and are limited to 20% of the total embedded emissions. Default values count as “estimations” under these rules.

Nature of default values:
These represent a global weighted average based on production volumes. Developed by the European Commission’s Joint Research Centre (JRC), they account for data from the EU’s main trading partners (15–20 countries per sector).

Future (2026 onwards):
A new set of default values will apply. These will reflect the average emissions intensity for each exporting country, increased by a markup. The exact figures will be decided in 2025.

Why securing supplier-specific emissions data is critical for reducing costs in 2026

Relying on default or estimated values can lead to higher costs, as these values are often set conservatively to encourage the use of actual data. Accurate data collection also supports better decision-making and risk assessment related to CBAM obligations. ​

^Building the foundation for more accurate and cheaper certificate management

Having solid systems in place for emissions data collection and reporting is crucial for managing CBAM certificates effectively. This includes:​

• Implementing processes to gather accurate emissions data from suppliers.​
• Training staff on CBAM requirements and reporting procedures.​
• Using digital tools to streamline data management and reporting.​

Preparing for CBAM’s definitive phase in 2026

From 1 January 2026, CBAM will shift into its definitive phase. This means the start of financial obligations for importers, on top of ongoing reporting. Here’s what companies need to prepare for:

CBAM reporting moves from quarterly to annual

Importers will need to submit a single, verified CBAM report each year covering all in-scope goods imported the previous calendar year. The deadline to submit is 31 May.

New requirement: Purchase CBAM certificates

Importers must buy CBAM certificates to cover the emissions embedded in their imported goods. One certificate = one tonne of CO₂. There’s no fixed quota. Your certificate obligation is directly tied to the actual emissions you reported.

Certificate prices will mirror the EU ETS

The price of CBAM certificates is linked to the average weekly price of EU ETS allowances. This means it can fluctuate with the carbon market. The more emissions embedded in your imports, the more you’ll owe, so accurate data can significantly affect your costs.

Annual certificate surrender

By 31 May each year, you’ll need to:

• Submit your verified annual emissions report for the previous year
• Surrender the equivalent number of CBAM certificates through the EU’s registry
  

Remember: Failure to surrender enough certificates will trigger a penalty of €100 per excess tonne from 2026, plus the obligation to purchase and surrender the missing amount.

Stronger data verification and audit requirements

Unlike the transitional phase, all emissions data reported from 2026 onward must be verified by an independent, accredited verifier. Regulators will also step up audits and enforcement. 

So, expect closer scrutiny of:

• The accuracy of your emissions data
• Your calculation methodology
• Supplier documentation and transparency

CBAM reporting checklist for 2025

Here are the critical steps every importer should take this year (if you haven’t done so already):

1. Map CBAM-covered goods and related emissions sources

Start by identifying all imported goods that fall under the current CBAM scope: iron and steel, cement, aluminium, fertilisers, hydrogen, and electricity. Match these against their CN codes to confirm they’re in scope.

Then, trace each product back to its production facility and pinpoint where direct and (if applicable) indirect emissions occur in the supply chain.

2. Build supplier engagement to gather primary emissions data

As of January 2025, default emissions values are no longer allowed, except in very limited cases. That means your suppliers need to provide verified emissions data based on the EU’s official methodology.

This includes:

• Direct emissions (Scope 1) from production processes. 
• Indirect emissions (Scope 2) from electricity use, where applicable (e.g. for cement and fertilisers).
• Activity data such as production volumes, energy consumption, and fuel use.
• Production processes and routes used for each product
• Emission factors used in calculations.
• Verification documents showing compliance with the EU’s methodology.

Use 2025 to identify key suppliers for CBAM-covered goods, confirm they are tracking the correct data using the EU method, and set up clear instructions and data-sharing processes.

Typically, production data and emissions calculations come from your suppliers, while you, as the importer, are responsible for reviewing their methodology, ensuring completeness, and arranging third-party verification if required. 

Be sure to engage the right supplier contacts early. This is usually handled by their sustainability, compliance, or plant operations teams.

3. Set up centralized CBAM reporting workflows

If you haven’t already, 2025 is the time to move away from fragmented or manual systems and adopt a structured, auditable approach to emissions reporting. We recommend using a dedicated ESG software platform like Coolset, which is built to support evolving regulatory frameworks like CBAM. 

The right platform helps you:

• Centralize emissions data from suppliers
• Ensure consistency with the EU’s official calculation methodology
• Catch missing or inaccurate data early
• Submit reports on time through the CBAM Transitional Registry

4. Assign ownership across key teams

CBAM compliance isn’t a sustainability-only task. It requires input from multiple departments:

• Sustainability teams handle emissions calculations and ensure data aligns with EU methods
• Procurement teams manage supplier data requests and follow-up
• Finance teams begin forecasting and budgeting for certificate purchases
• Legal or compliance leads oversee timely reporting and future audits

Make sure to clearly define responsibilities and communication workflows between these teams.

5. Forecast future certificate liabilities based on 2025 emissions data

Use your 2025 emissions reports to estimate how many CBAM certificates you’ll need in 2026, and what that might cost.

This means:

• Summing total embedded emissions per product category
• Monitoring EU ETS prices to model potential liabilities
• Factoring in any carbon prices already paid abroad (which may reduce your obligation)
  

These estimates will help inform financial planning, pricing strategies, and conversations with leadership.

Use 2025 wisely, or pay for it later

CBAM is a structural change to how emissions are priced in global trade. For mid-market importers, this year is your last chance to set up the systems that will prevent compliance headaches in 2026.

The stakes are high: bad data today means higher costs tomorrow. But with the right preparation, your business can stay ahead, not just complying with CBAM, but by using it as a catalyst to build more resilient, transparent supply chains.

Need help getting CBAM-ready?

Coolset makes sustainability reporting simpler for mid-market enterprises. From supplier engagement to emissions tracking and EU-aligned workflows, we help you manage compliance, without the chaos.

Get in touch to learn how we can support your CBAM journey today.