Published 21 May 2026 · 10 min read · CBAM Reporter →

EU CBAM deadline — 31 May 2026: The first annual EU CBAM declaration for goods imported in 2025 is due by 31 May 2026. EU-based importers must act now. Submit your declaration →

The Carbon Border Adjustment Mechanism (CBAM) is reshaping global trade policy. The EU launched its CBAM transitional phase in October 2023, and the UK is introducing its own parallel mechanism. For businesses trading across both regimes, understanding the differences — and the compliance requirements — is critical in 2026 and beyond.

What Is CBAM?

CBAM is a carbon pricing instrument applied to imports of carbon-intensive goods from countries with weaker or no carbon pricing. Its purpose is to prevent "carbon leakage" — the risk that companies move production to countries with laxer climate regulation to avoid paying for carbon emissions.

In practical terms, CBAM requires importers to:

  1. Report the embedded (or "embodied") carbon emissions of imported goods
  2. Acquire and surrender certificates corresponding to those emissions
  3. Receive credit for any carbon price already paid in the country of production

EU CBAM vs UK CBAM — Key Differences

🇪🇺 EU CBAM

  • Transitional phase: Oct 2023 – Dec 2025
  • Full phase-in: 2026–2034
  • First annual declaration: 31 May 2026
  • Sectors: Steel/iron, aluminium, cement, fertilisers, electricity, hydrogen
  • Certificate system: EU CBAM certificates (€/tCO₂)
  • Registry: CBAM registry via national customs authority
  • Declarant must be authorised by 31 Dec 2024

🇬🇧 UK CBAM

  • Launch: 1 January 2027
  • Consultation closed 2024; final legislation 2025
  • First annual payment year: 2028
  • Sectors: Same core sectors as EU CBAM + glass and ceramics added
  • Mechanism: Levy on imports (not certificate system)
  • Administered by HMRC
  • Based on UK ETS carbon price

Key insight: The EU and UK use different mechanisms — the EU uses a certificate purchase system, while the UK will use a direct levy administered through HMRC. Both ultimately price the carbon content of imported goods at the prevailing domestic carbon price.

EU CBAM: What You Must Do Before 31 May 2026

If your company imported any of the following goods into the EU during 2025, you have a binding obligation to submit an annual CBAM declaration by 31 May 2026:

The annual declaration must include:

Penalty risk: Failure to submit the annual declaration by 31 May 2026 or submitting incorrect data can result in penalties of €10–50 per tonne of CO₂ equivalent that was not properly reported, in addition to the cost of the CBAM certificates themselves.

EU CBAM: The Certificate Phase (2026 Onwards)

From 2026, EU importers must purchase CBAM certificates to cover the embedded emissions of their imports. The certificate price tracks the EU ETS carbon price. Key points:

Preparing for UK CBAM (2027)

UK businesses importing covered goods from non-UK countries should begin preparing now, even though UK CBAM formally launches on 1 January 2027:

1. Data readiness

Start collecting embedded emissions data from your non-UK suppliers now. Getting accurate production emissions data from steel mills in India, China or Turkey takes months of engagement. Don't wait until 2027.

2. Supply chain mapping

Map which goods you import and from which countries. Some countries will have carbon pricing schemes that reduce the UK CBAM liability. The UK government will publish a list of qualifying carbon prices.

3. System setup

HMRC will operate the UK CBAM levy through a new online service. Register early to avoid delays. The reporting methodology is expected to broadly mirror the EU approach.

4. Dual exposure for EU-UK traders

Companies that both import into the EU and export into the UK from third countries may face CBAM obligations in both jurisdictions. Plan for dual reporting requirements.

Simplifying CBAM Reporting

Whether you're dealing with EU CBAM now or preparing for UK CBAM in 2027, the core challenge is the same: collecting embedded emissions data from multiple suppliers, calculating totals by product category and origin country, and generating a compliant report.

An online tool purpose-built for CBAM reporting can handle this in minutes rather than weeks:

CBAM Reporter — Annual Declaration Online

Prepare your EU CBAM annual declaration for 2025 before the 31 May 2026 deadline. Free to start, no installation.

Start your CBAM report →