As the EU’s Carbon Border Adjustment Mechanism (CBAM)  enters its definitive phase, reporting is no longer just a regulatory exercise. Imports from January 2026 onwards create direct certificate cost exposure, which makes accurate, complete reporting a business-critical requirement.

CBAM reporting obligations are already in force, and the quality of your emissions data now feeds directly into future cost and compliance outcomes. Gaps in supplier data, unclear ownership, or inconsistent processes can lead to inflated emissions, higher certificate exposure, and enforcement risk.

Staying compliant in 2026 requires coordination across sustainability, procurement, and finance. This article explains the CBAM reporting requirements that apply today, what has changed in 2026, and where mid-market companies should focus to run CBAM reporting as a reliable, repeatable process

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.

{{custom-cta}}

CBAM reporting phases 

To help businesses adjust, CBAM s introduced in phases. See our detailed breakdown of the CBAM timeline and phases. Below is a quick overview:

Transitional phase (1 October 2023 – 31 December 2025)
Reporting only. Now that 2025 has come to a close, the European Commission will review CBAM’s progress and consider expanding its scope.

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: What to expect in both phases

2025 was the final year of the reporting-only phase. No payments were required, but quarterly reports were required to be submitted on time and based on the EU’s official calculation methodology.

For a full breakdown of what to expect across both phases read our CBAM timeline, deadlines, and phases guide.

What to include in a CBAM report

Importers of CBAM-covered goods must submit an annual CBAM declaration covering all in-scope imports for the year through the CBAM Transitional Registry. The report must be based on product- and installation-level data and align with the EU methodology.

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).

{{cbam-calculator-injectable}}

Why data quality matters

The emissions data you report from now onwards will directly affect how many CBAM certificates you'll need to purchase, and how much those will cost.

Incomplete or incorrect reports lead to penalties of €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.

Why non-EU suppliers matter

Non-EU suppliers are not directly regulated by CBAM, but they play a critical role in helping EU importers comply. Importers cannot measure emissions themselves, they rely on suppliers to provide detailed, accurate data on the embedded emissions of the goods being exported. To streamline this process, 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. For suppliers, understanding the emissions calculations and aligning with the EU’s methodology is essential.

Using standard tools, such as the EU template or software solutions like Coolset, can make the process easier and ensure data meets compliance standards.

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 happened on 1 January, 2026?

As of 1 January 2026, CBAM has entered its definitive phase. This means:

• Reports shift from quarterly to annual.
• The first verified annual report for 2026 is due by 30 September 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 is transitioning to the CBAM Registry for the definitive phase. The CBAM Registry will manage annual declarations and, once available, certificate purchasing and surrender.

Only authorized CBAM declarants can import CBAM-covered goods from 2026 onward. Applications to become an authorized CBAM declarant opened on 31 March 2025. Once approved, importers receive a CBAM account number and access to the CBAM Registry.

Default values vs. actual emissions: What companies should know

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):
From 2026 imports onward, CBAM creates certificate cost exposure, so any overstatement in emissions translates into more certificates to surrender. The EU also moves toward default values that are more granular and include an explicit markup, which makes reliance on defaults progressively more costly.

What companies should do: Use default values only as a last resort. Prioritize installation-level supplier data aligned with the EU methodology and build a clear escalation path for suppliers that cannot deliver usable data.

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.​

CBAM’s definitive phase in 2026

As of 1 January 2026, CBAM has entered 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 has moved from quarterly to annual

Importers need to submit a single, verified CBAM report each year covering all in-scope goods imported the previous calendar year. The first report for 2026 must be submitted by 30 September 2027.

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.

Check our CBAM certificate article to understand how certificates work, when to surrender them, and how to forecast costs in advance. The sale of CBAM certificates will start in February 2027, until then, companies should monitor their imported emissions to later surrender the equivalent number of CBAM certificates as they become available.

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 30 September 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

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

Default emissions values exist but should be treated as a last resort, as they are conservative and increase CBAM certificate exposure. 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 this time 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, now 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.

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.