Question 1

Does the calculator follow HMRC's methodology?

Accepted Answer

It's an independent planning tool, not an HMRC product, and it is aligned to The Carbon Border Adjustment Mechanism (Emissions and Verification) Regulations 2026 (in force 1 January 2027) and the System Boundaries Document v1.00 and Force of Law Notice published by HMRC. It follows HMRC's Carbon Price Relief (CPR) methodology and Regulation 5's eight-step actual emissions calculation, including emissions intensity displayed to five decimal places per Reg. 5 Step 7. CPR claims require GACI-accredited verification. Rates use HMRC's illustrative sector rates (16 October 2026); default values are HMRC's, published 16 October 2026 by CN code. All estimates should be verified with a qualified tax adviser.

Question 2

What monitoring period do I use for 2027 imports?

Accepted Answer

Under Regulation 9 there are two options. Linked to the date of import: for goods imported in 2027, use the most recent verified data from the year of import or the preceding calendar year; from 1 January 2028, use the most recent verified data from the two calendar years before the year of import. Or linked to production: use verified data from the calendar year in which the good was produced (HMRC policy summary, updated 16 October 2026).

Question 3

What counts as a qualifying carbon pricing scheme for UK CBAM?

Accepted Answer

Under HMRC's secondary legislation, a qualifying carbon pricing scheme must be a carbon tax, an emissions trading scheme, or a scheme that prices emissions embodied in imported goods, and must meet all of the following: it is administered by or on behalf of a tier of government or a supra-national organisation; the use of revenue collected is determined by that government or supra-national body; participation by installations is mandated by law; the rules, scope, and headline carbon price of the scheme are publicly available; and the scheme imposes a direct or indirect cost on relevant emissions. HMRC announced a confirmed list of sixteen Qualifying Carbon Pricing Schemes on 27 August 2026 (based on information as of 19 June 2026), including the EU-ETS, K-ETS, CN-ETS and India's CCTS — but not every ETS qualifies automatically: Turkey's TR-ETS, for example, does not currently appear on that list. HMRC says the list is not exhaustive and is kept under review: an importer who thinks a scheme qualifies can send its details to cbampolicyteam@hmrc.gov.uk. Qualification alone does not guarantee a CPR deduction, either: where a scheme grants free allocation to a sector (currently the case for steel under K-ETS and CN-ETS, and India's intensity-based CCTS is likewise yielding no meaningful price yet), the carbon price actually paid — and therefore the CPR claimable — may be zero. CPR is based on the price actually paid, not the headline scheme price. Voluntary carbon credits cannot generate Carbon Price Relief.

Question 4

Who can verify my emissions data for UK CBAM?

Accepted Answer

Under Regulation 12, your verifier must be independent of the importer, the installation that produced the CBAM good, and any installation that produced a precursor good. HMRC guidance confirms two separate accreditation tiers. For general emissions verification, the verifier must be accredited by a body that is a full member of Global Accreditation Cooperation Incorporated (GACI), and accredited to ISO/IEC 17029:2019 and ISO 14065:2020. For Carbon Price Relief claims specifically, two further standards are required on top of these — ISO 14064-3:2019 and ISO 14066:2023 — a distinct, higher bar than general emissions verification, since GACI Multilateral Recognition Agreement signatory status also applies. CBAM Proof acts as the preparation layer — we do not replace the statutory verifier. Note: these are the qualifying standards, not a list of approved verifiers. HMRC has said it has no current plans to publish one, so check any specific provider's accreditation against these criteria directly, and against the correct tier for what you're asking them to verify.

Question 5

What records do I need to keep for UK CBAM?

Accepted Answer

Regulation 16 requires six years of records covering: installation address, operator company number, monitoring period dates, the full verification report or good-specific verification summary, the verifier's name, address and company number, and emissions intensity for the CBAM good and any precursor goods — all to five decimal places per Reg. 5 Step 7.

Question 6

How quickly can I get a full CBAM readiness audit?

Accepted Answer

The free calculator gives instant estimates. A CBAM Readiness Audit (£2,500) delivers a board-ready report within 48 hours, including supply chain analysis, liability quantification, precursor chain mapping, and recommended next steps. Registration triggers on a rolling basis — when your trailing 12-month imports reach £50,000, or when you expect to cross it within the next 30 days. Registration is normally due within 30 days of that trigger; for anyone triggering during 2027, HMRC's first-year easement extends the deadline to 31 January 2028 (SI 2026/830; HMRC policy summary, updated 16 October 2026). Monitor monthly so you know your trigger date.

Question 7

What is the difference between UK CBAM and EU CBAM?

Accepted Answer

UK CBAM and EU CBAM are separate regimes with different scope, timelines and methodologies. UK CBAM covers iron, steel, aluminium, cement, fertiliser and hydrogen, applies from 1 January 2027, and follows HMRC's own Carbon Price Relief and default-value framework under the Carbon Border Adjustment Mechanism (Emissions and Verification) Regulations 2026. A CBAM certificate or payment made under the EU regime does not satisfy your UK CBAM obligations, and vice versa. Importers trading with both markets must run the calculations separately.

Question 8

How is UK CBAM liability actually calculated?

Accepted Answer

Regulation 5 sets out an eight-step actual emissions calculation, run per CBAM good and precursor good, ending in an emissions intensity figure displayed to five decimal places. The charge is on direct emissions. Where actual verified data is unavailable, HMRC's default values apply instead (one default value per CN code, whatever the origin, published 16 October 2026); the Finance Act 2026 allows defaults to be set so that using one gives no advantage over verified data (Sch 17 para 11). Gross liability is the embodied emissions multiplied by HMRC's CBAM rate for the sector, which HMRC publishes quarterly. It is then reduced by any Carbon Price Relief you can evidence for carbon pricing already paid on the good.

Question 9

Where do I find the HMRC default value for my goods?

Accepted Answer

HMRC published default values on 16 October 2026 for each of the five sectors, by CN code: 478 codes for iron and steel, 58 for aluminium, 27 for fertilisers, 6 for cement and one for hydrogen. They are in tonnes of CO₂e per tonne of product and apply whatever the origin. HMRC says they replicate the Force of Law notice, and you must use them if you are not reporting actual verified emissions. Two rules matter. A return filed on defaults cannot later be amended with actual emissions data. And you cannot use actual data for a precursor good and a default for the final good, although you can use a default for a precursor alongside actual data for the processes that turn it into the final good. HMRC sets each default as a single product-level value, calculated on a trade-weighted average basis with EU data excluded, plus a 10% mark-up in every sector except fertiliser. The values apply for 2027 and 2028, and HMRC has committed to country-specific defaults from 2029, when the mark-up will be reviewed (HMRC written statement, 16 October 2026). The calculator above shows the default for each in-scope CN code.

Question 10

Do I owe UK CBAM if my supplier already pays a carbon price?

Accepted Answer

Possibly less than the headline figure, but rarely zero. Carbon Price Relief (CPR) is based on the carbon price actually paid on the goods, not the scheme's headline price — and some schemes grant free allocation that reduces the price actually paid to nil for certain sectors. CPR claims also require GACI-accredited verification evidence, so an unverified claim of 'we already pay carbon tax' will not reduce your liability on its own.

Question 11

What happens if I miss the UK CBAM registration deadline?

Accepted Answer

Registration triggers the moment either your trailing 12-month imports reach £50,000 or you expect to cross that threshold within the next 30 days. Normally you must register within 30 days of that trigger — but under HMRC's first-year easement, anyone triggering during 2027 has until 31 January 2028 to register. That easement exists partly because HMRC's own guidance confirms the registration service itself will not open until 1 January 2028 — but your registration obligation and record-keeping duties still run from your original trigger date, not from when the portal opens. Missing your deadline exposes an importer to HMRC penalties and interest — so businesses that monitor import value monthly know exactly when their clock started.

HMRC's default figures don't know your mill. That's expensive.

Most importers don't know what they owe

Liability set by defaults

CPR left unclaimed

Record-keeping gap

Rolling registration trigger

How to estimate your CBAM exposure now

The businesses that wait will be 12 months behind

Know your number before HMRC does.

Adaptive data handling

Monitoring that doesn't sleep

Fast output, human sign-off

Your indicative CBAM liability in 90 seconds

CBAM Compliance Services & Pricing

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