UK CBAM — Schedule, Registration and Obligations for Polish Exporters

What Is UK CBAM and How Does It Differ from EU CBAM?

The UK and EU have developed separate CBAM frameworks. Understanding the difference is essential for Polish businesses that trade in both directions.

UK CBAM — enacted through the Finance Act 2026, in force from 1 January 2027

UK CBAM was enacted through the Finance Act 2026 and comes into force on 1 January 2027. The mechanism places a carbon price on imports into the UK of carbon-intensive goods from countries where producers do not face a carbon cost equivalent to the UK Emissions Trading Scheme (UK ETS). It is a tax paid to HMRC by the importer — there are no CBAM certificates. CBAM rates are published by the government at the start of each quarter from 1 January 2027, and default emissions values are published on GOV.UK. Polish exporters should monitor the official collection page for updates: gov.uk/government/collections/carbon-border-adjustment-mechanism. Source: Finance Act 2026; gov.uk/government/collections/carbon-border-adjustment-mechanism (dateModified 2026-04-09).

EU CBAM — already enacted (Regulation (EU) 2023/956)

For completeness: the EU CBAM (Regulation (EU) 2023/956) is already enacted and creates obligations for importers bringing goods into the EU from third countries — including from the UK. The definitive period started on 1 January 2026; CBAM certificates for 2026 imports are sold from 1 February 2027 and surrendered with the annual declaration due by 30 September 2027. This affects Polish companies importing from the UK in sectors including steel, iron, aluminium, cement, fertilisers, electricity and hydrogen. Polish importers already have reporting obligations since the transitional phase began in October 2023. This article does not cover EU CBAM in detail — see our separate article on EU CBAM vs UK CBAM comparison.

Sectors covered by UK CBAM

UK CBAM covers goods in the following sectors:

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

The exact commodity codes are listed by HMRC in Check which goods are in scope of CBAM. Registration is required once an importer's CBAM goods reach £50,000 in value over 12 months (or are expected to within the next 30 days). Note that the UK sector list is broadly similar to but not identical to the EU CBAM sector list — in particular, UK CBAM does not cover electricity, and ceramics and glass are not in scope. The list of goods in scope is published on GOV.UK.

What Polish Exporters Need to Do Now

Given that the UK CBAM is proposed but not yet enacted, the appropriate response for Polish exporters is to monitor and prepare — not to register or report.

Phase 1 (now until HMRC implementing regulations are published): assess and prepare

UK CBAM has been enacted through the Finance Act 2026. Polish companies exporting goods in the covered CBAM sectors to the UK should now: (1) confirm whether your products fall within the sector scope based on HS codes; (2) calculate or estimate the embedded carbon content of your exported goods — this will be required for UK CBAM declarations from 1 January 2027; (3) follow the quarterly CBAM rates published by the government, which reflect the UK ETS price adjusted for free allocation; (4) monitor HMRC guidance at gov.uk/government/collections/carbon-border-adjustment-mechanism for registration procedures and technical details. Preparation — not merely monitoring — is now appropriate.

Phase 2 (once HMRC implementing regulations are published): registration

Under the Finance Act 2026, the person liable for UK CBAM is the importer of the CBAM goods — the person in whose name the customs declaration is made, not the Polish exporter and not a customs agent who files the import declaration on the importer's behalf. Importers must register with HMRC using their Government Gateway account once their CBAM goods reach the £50,000 threshold over 12 months (or are expected to within the next 30 days); for the first year, registration is possible until 31 January 2028. Returns may be filed by the importer or their tax agent, but only the importer can register. Polish exporters will need to provide embedded carbon data to their UK buyers so that the UK importer can complete CBAM declarations accurately. This data preparation should begin now. The first accounting period runs from 1 January to 31 December 2027, with the return and payment due by 31 May 2028; later periods are quarterly. Source: CBAM: Policy summary (GOV.UK). Contact a customs broker before taking any action.

Embedded carbon calculation — what will be required

Under UK CBAM, importers declare the embodied emissions of their CBAM goods and pay tax calculated as embodied emissions × the CBAM rate, less any carbon price relief for carbon pricing already paid abroad. CBAM rates are calculated and published by the government at the start of each quarter from 1 January 2027 and reflect the UK ETS price adjusted for free allocation. At the start, only direct emissions are in scope — indirect emissions (from electricity used in production) are not. Where actual data is unavailable, default emissions values published on GOV.UK can be used. For Polish exporters, this means: (1) calculating the direct emissions from production processes; (2) providing this data to your UK buyer so they can use actual rather than default values. This article reflects the legal position as of 2026-10-05. Contact a customs broker before taking any action.

UK CBAM Price and Financial Impact — Preliminary Assessment

Although UK CBAM is not yet in force, a preliminary financial assessment helps exporters understand the potential impact on competitiveness and pricing.

UK ETS carbon price — the reference for CBAM charges

The UK CBAM charge will be based on the UK Emissions Trading Scheme (UK ETS) carbon price, minus any carbon cost already paid in the country of production. The UK ETS price has fluctuated significantly — it was approximately £35–£45 per tonne of CO2 equivalent in early 2026. Check the current price at: gov.uk/guidance/uk-ets. For a Polish steel exporter with an embedded carbon intensity of 1.8 tonnes CO2/tonne of steel: if the EU ETS carbon cost already paid is equivalent to or greater than the UK ETS price, no CBAM charge would apply (the mechanism is designed to prevent double-charging). For exports from Poland where the EU ETS cost is demonstrably lower than the UK ETS price, a top-up charge would apply. Once the enabling act specifies the exact calculation methodology, we will update this analysis.

Impact on pricing and contracts

Polish exporters in CBAM sectors who sell to UK buyers should review long-term contracts now. If a contract fixes the price in GBP for deliveries after 1 January 2027 without a CBAM adjustment clause, the exporter may absorb the CBAM cost without the ability to pass it on. Recommended action: include a CBAM price adjustment clause in new contracts referencing the UK ETS price and the final CBAM rate. This is a standard commercial risk management step already adopted by exporters managing EU CBAM exposure. Easy Clearance can provide guidance on customs documentation requirements once UK CBAM is enacted. Contact us: WhatsApp +44 7404 091503 | tel +44 7404 091503. This article reflects the legal position as of 2026-10-05. Contact a customs broker before taking any action.

What the current rules say

UK CBAM was enacted through the Finance Act 2026 and comes into force on 1 January 2027. It targets imports of carbon-intensive goods (aluminium, cement, fertilisers, hydrogen, iron and steel) into the UK. It is a tax paid to HMRC by the importer through CBAM returns — not a certificate system — with quarterly CBAM rates linked to the UK ETS price. Polish exporters should now confirm their sector scope, calculate embedded carbon data, and prepare for registration through their UK buyers. The EU CBAM (Regulation (EU) 2023/956) is already enacted and separately affects imports into Poland from the UK. This article reflects the legal position as of 2026-10-05 — contact a customs broker before taking any action.

FAQ — frequently asked questions

Is the UK CBAM already enacted?

Yes. UK CBAM was enacted through the Finance Act 2026 and comes into force on 1 January 2027. It is a tax paid to HMRC by the importer (no CBAM certificates); registration is via Government Gateway once CBAM goods reach £50,000 over 12 months, and the first return and payment (for 2027) are due by 31 May 2028. Monitor: gov.uk/government/collections/carbon-border-adjustment-mechanism.

Which sectors does UK CBAM cover?

According to GOV.UK, UK CBAM covers goods from the aluminium, cement, fertiliser, hydrogen, and iron and steel sectors. Electricity, ceramics and glass are not in scope. The list of goods is published on GOV.UK.

What should Polish exporters do now to prepare for UK CBAM?

UK CBAM has been enacted through the Finance Act 2026 (in force 1 January 2027). Confirm whether your products fall in the covered sector list. Begin calculating the embedded carbon content of your exports — this data will be required for CBAM declarations. Include CBAM price adjustment clauses in new contracts for deliveries after 1 January 2027. Monitor HMRC guidance at gov.uk/government/collections/carbon-border-adjustment-mechanism.

Is UK CBAM the same as EU CBAM?

No — they are separate mechanisms. The EU CBAM (Regulation (EU) 2023/956) is already enacted and covers imports into the EU from third countries including the UK. The UK CBAM was enacted through the Finance Act 2026 and covers imports into the UK from third countries including Poland/EU, from 1 January 2027. Both can apply to the same goods traded in opposite directions.

Who pays the UK CBAM charge — the Polish exporter or the UK buyer?

UK CBAM is paid to HMRC by the importer — the person in whose name the customs declaration is made — not by the Polish exporter. A customs agent filing the import declaration does not become liable. However, the UK importer will need embedded carbon data from the Polish exporter to complete their CBAM declaration. In practice, exporters with higher embodied emissions (or without documented data, so that default values apply) may face commercial pressure on price.

Official sources

• UK Carbon Border Adjustment Mechanism — GOV.UK guidance — GOV.UK
• EU CBAM — Regulation (EU) 2023/956 — EUR-Lex
• UK ETS — carbon price and market data — GOV.UK