Get your suppliers’ emissions data, and keep the records HMRC wants.

What the letters ask suppliers for

1. 1. Always neededOperator name and registration detailsName of the installation operator, its corporate or activity registration number, full address and email address.
2. 2. Always neededInstallation name, UN/LOCODE and addressName of the installation (factory, plant or facility), its UN/LOCODE, full address in English, and its unique installation identifier if one exists.
3. 3. Always neededInstallation coordinatesLatitude and longitude of the installation to six decimal places, as the verification report must show. The operator's emissions report gives the coordinates of the main emission source.
4. 4. Always neededNominated contact at the installationName, job title and email address of the nominated person at the installation. The carbon pricing verification form also asks for a contact name, address and phone number.
5. 5. Always needed8-digit commodity code and descriptionThe 8-digit UK commodity code and description for each CBAM good supplied. Goods are in scope only if their code is listed in Schedule 16 to the Finance Act 2026.
6. 6. Always neededNet weight per consignment (kg)Weight excluding all packing materials and containers, at the time of import, in kilograms. HMRC names manufacturers as a source of weight records; net mass is recorded to up to 6 decimal places.
7. 7. Always neededInvoice value and termsCommercial invoice values so the importer can establish customs value, which is the value used for CBAM records and the £50,000 registration threshold.
8. 8. Always neededCountry of origin and origin evidencePlace of origin under UK non-preferential rules of origin, with supporting evidence. Every CBAM return states it and the importer must keep records evidencing it.
9. 9. Always neededProduction process and production routeThe CBAM production process and route used, as defined in the System Boundaries Document, for example basic oxygen or electric arc furnace for crude steel, blast furnace for pig iron, or primary smelting or secondary melting for aluminium.
10. 10. Always neededMonitoring period (calendar year)The calendar year the emissions data covers. For goods imported before 1 January 2028: the import year or the preceding year with verified data, or the year the goods were produced.
11. 11. Always neededQuantity of CBAM goods producedTotal quantity of each CBAM good produced in the monitoring period, per production process, in functional units and in tonnes. This activity level is the divisor for emissions intensity.
12. 12. Always neededInstallation and attributed direct emissionsTotal direct emissions of the installation in the monitoring period and the relevant emissions attributed to each production process, in tCO2e, within the System Boundaries Document boundaries.
13. 13. Always neededVerified emissions intensity per goodEmbodied direct emissions per tonne of each CBAM good, in tCO2e, rounded to five decimal places (step 7). This is the figure the importer reports on the CBAM return.
14. 14. Always neededData quality and share of default valuesWhether the emissions intensity was fully monitored or used any default values, and the share of the emissions intensity based on default values.
15. 15. If applicableNon-CO2 greenhouse gasesAluminium goods must cover perfluorocarbons; nitric acid, potassium nitrates, nitrogenous fertilisers (3102) and mixed fertilisers (3105) must cover nitrous oxide. Convert at N2O 265, CF4 6,630 and C2F6 11,100 tCO2e per tonne.
16. 16. If applicableClinker content (cement)For 2523 10 00, 2523 21 00, 2523 29 00 and 2523 90 00 the functional unit is tonnes of clinker contained. Supply the clinker to cement ratio so intensity converts to a tonne of good.
17. 17. If applicableNitrogen content (fertilisers)Functional unit is kilograms of nitrogen contained. Supply N as ammonium, nitrate, urea and other forms, total N, and concentration or purity where listed, so intensity converts to a tonne of good.
18. 18. If applicableSteel parameters (crude steel, iron or steel products)Main reducing agent used in precursor production (if known), mass % of Mn, Cr, Ni and other alloy elements, tonnes of scrap per tonne of product, and % pre-consumer scrap.
19. 19. If applicablePig iron, DRI and ferro-alloy parametersPig iron and DRI: main reducing agent and mass % of Mn, Cr, Ni and other alloys. FeMn, FeCr, FeNi: mass % of the named metal and of carbon.
20. 20. If applicableAluminium parametersTonnes of scrap used per tonne of product, % pre-consumer scrap, and the total % of elements other than aluminium where that exceeds 1%.
21. 21. If applicablePrecursor goods usedEach relevant precursor listed for the goods category in the System Boundaries Document, with commodity code, name, quantity used per production process, and whether made in-house or bought in.
22. 22. If applicableBought-in precursors on actual valuesCountry of origin, producing operator and installation, monitoring period, emissions intensity, and the precursor verifier's name, accreditation number, accreditation body, expiry date and report date.
23. 23. If applicablePrecursors on default valuesCommodity code, name, country of origin where known, the default value applied and quantity used. Default precursor values may be used even where the final good uses actual data.
24. 24. If applicableUK-origin precursor evidenceEvidence that any precursor originated in the UK, so its embodied emissions are not charged. The return must state whether a UK-origin CBAM good was used to make the imported good.
25. 25. If applicableComplex good intensity breakdownEmissions intensity split between the production process's own attributed intensity and each precursor's share (equations 53 to 55), shown separately where a precursor faced a different carbon pricing scheme.
26. 26. Always neededVerification report or good-specific verification summaryThe verifier's report, or the good-specific summary for this good, stating the data is verified as satisfactory. The importer must keep it for 6 years; without it a default value must be used.
27. 27. Always neededVerifier identity and accreditationVerifier name, address and email, accreditation number, accreditation body and its country, accreditation expiry date and scope of accreditation, plus the report's unique identifier and monitoring period.
28. 28. If applicableCarbon pricing scheme and jurisdictionJurisdiction and name of any carbon pricing scheme the installation was subject to, and whether it prices emissions directly per tCO2e or indirectly through fuel emissions factors.
29. 29. If applicableCompleted carbon pricing verification formHMRC's form completed and signed by an accredited independent verifier, one per installation, with data from one of the two calendar years before the import year. Without it no relief can be claimed.
30. 30. If applicableInstallation emissions split by scheme elementInstallation emissions for the year (form box C2) split into headline price, free allowances, below threshold, graduated price and greenhouse gas removal price (boxes C3 to C7), all in tCO2e.
31. 31. If applicableCompensation, rebates or refundsWhether the installation received or is due compensation linked to its emissions for the same year, with the amount and currency (form section D). This reduces the effective carbon price.
32. 32. If applicableEmissions factors for indirect pricingWhere the scheme prices fuels rather than tCO2e, the scheme's emissions factors, taken from or calculated using IPCC, IEA or UNFCCC methodology, and confirmed by the verifier.
33. 33. If applicableCarbon price on precursorsA separate carbon pricing verification form for each precursor made at another installation under a qualifying scheme, because relief is worked out separately for each.

What the records register covers

6 years, in writing (paper or electronic). Records relating to an accounting period: 6 years from the day after that period ends. Other records: 6 years from the day created (SI 2026/802 reg 6). Repayment claim records: 6 years from sending the claim. Keep records from 1 January 2027. Fixed penalty of £500 for failing to keep or preserve a record (Finance Act 2026, Sch 17 para 39), unless there is a reasonable excuse (para 40). Separate penalties may apply if you do not provide information or documents HMRC asks for.

• Import declaration or document referenceReference of the import declaration or other document evidencing the import. HMRC accepts import declarations, entry acceptance advice, bills of lading and commercial documents.
• Commodity code (8 digits)The 8-digit commodity code for each CBAM good imported.
• Goods descriptionDescription of the good, kept with the commodity code.
• CBAM sectorAluminium, cement, fertilisers, hydrogen, or iron and steel. Registration asks for estimated weight per sector, so tag each line.
• Date of import (tax point)Date the good was imported into the UK, meaning when it passed the tax point (first entered the UK or cleared customs).
• Quarter of importCalendar quarter the good passed the tax point. The first return (1 January to 31 December 2027) must state the quarter for each good.
• Value (£, customs value)Value as determined for customs purposes (Part 12 of the Customs (Import Duty) (EU Exit) Regulations 2018, or the UCC for some Northern Ireland cases).
• Net weight (kg, up to 6 decimal places)Weight without packing, at import, in kg. Over 1 kg: round .001 to .499 down and .5 to .999 up. Under 1 kg: '0' plus up to 6 decimals.
• Weight evidenceDocument relied on for the weight, such as import declaration, commercial invoice, carrier weight record, bill of lading or packing list. HMRC may set the weight itself if records are missing.
• Place (country) of originCountry of origin under UK non-preferential rules of origin. Stated on every return.
• Proof of origin heldRecord evidencing the place of origin, required for anyone who makes a return.
• Accounting period (return)The accounting period the good belongs to: 1 January to 31 December 2027, then quarters from 2028. Drives the retention date.
• Emissions basis (actual or default)Whether embodied emissions are reported using a default value or verified actual emissions intensity. Both are return items.
• Default value used (tCO2e per tonne)Where a default value is used, the level of the default value. HMRC published values by CN code on 16 October 2026, to apply from 1 January 2027 to 31 December 2028.
• Verified emissions intensity (tCO2e per tonne, 5 dp)Where actual data is used, the verified emissions intensity reported on the return. Policy summary says returns and records must hold this.
• Verification report or summary held (ID)Unique identifier of the verification report or good-specific verification summary supporting the intensity. Keep 6 years from the day after the accounting period. Not needed if a default value is used.
• Made using UK-origin CBAM good? (s.147(3))Whether the good was produced using another CBAM good of UK origin, which is a return item, with evidence of that UK origin.
• Exemption claimedPrivate use, UK origin, returned goods relief, or temporary admission with full relief. Records must show where s.147(2) applies to a good.
• Exemption evidence heldFor example proof of earlier UK export and same state (returned goods), production records or suppliers' declarations (UK origin), or the full relief import declaration (temporary admission).
• Qualifying carbon pricing schemeEvidence the good was subject to a qualifying carbon pricing scheme and the relevant elements of that scheme.
• Carbon pricing verification form heldCopy of the carbon pricing verification form obtained under reg 9, completed by a suitable verifier.
• Effective carbon price and workingsEvidence the effective carbon price was calculated under reg 12, including which scheme elements were used to decide the price.
• Public price evidence (prior quarter)Publicly available headline price, and any greenhouse gas removal or graduated prices, from the calendar quarter before import, with evidence of how any average was worked out.
• Relief in scheme currency and workingsEvidence of how the relief was calculated under reg 13 before conversion, including records on emissions embodied in any precursor good.
• HMRC exchange rate usedThe HMRC rate for the calendar quarter before import used to convert the relief to sterling.
• Carbon Price Relief claimed (£)Amount of carbon price relief shown on the return, rounded down to two decimal places after conversion.
• Repayment claim detailsReason for the claim, date the error was found, accounting period, details of the goods from the return, and date the CBAM was originally paid. Keep 6 years from sending the claim.
• Reimbursement recordsName and address of each person reimbursed, total amount, interest included, and date of each reimbursement, where a repayment is passed on to customers.
• Registration details providedName, contact details, principal place of business, business type, EORI number and VAT number given on registration, with any evidence supporting them.
• Date registration was triggeredThe date the backward or forward threshold test was first met. Registration asks for this date.
• Value of CBAM goods in the test periodValue of CBAM goods imported, or expected to be imported, in the 12-month or 30-day test period that triggered registration.
• Estimated weight per sector (next 12 months) and basisEstimated weight of CBAM goods per sector for the 12 months from triggering registration, and evidence of how you estimated it.