United Kingdom · Administrative guidance
UK publishes CBAM default emissions values and limits on switching to actual data
On 16 October 2026, HMRC published default emissions values for UK Carbon Border Adjustment Mechanism goods. For the forthcoming regime, importers may use these quantities instead of verified actual emissions, but the accompanying force-of-law notice remains an uncommenced draft.
- Official document:
- 16October2026 CBAM default-value guidance and draft DefaultValues ForceofLawNotice; FinanceAct2026 Schedule17 paragraph11; SI2026/995 regulations4–7
- Development date:
- 2026-10-16
Emissions intensity is not a tax rate
The figures are tonnes of carbon-dioxide equivalent per tonne of product, not sterling charges. Regulation 4 of the Carbon Border Adjustment Mechanism (Emissions and Verification) Regulations 2026, S.I. 2026/995, determines embodied emissions by multiplying the good’s weight by its default value. The regulations were made on 8 September and commence on 1 January 2027.[1][6]
HMRC’s cement table uses Combined Nomenclature codes rather than one sector-wide figure. For example, cement clinker under CN 25231000 has a value of 1.433 tCO2e per tonne, while non-white Portland cement under CN 25232900 has 1.375. The guidance says the values apply regardless of origin; the correct product classification still matters.[2]
Mixed data has limits
Default values may be used for precursor goods while actual data measures the processes turning them into the final good. HMRC does not permit the opposite combination: actual precursor data with a default for the final good. Its guidance also says a return submitted using default values cannot later be amended using actual emissions data.[2]
The draft notice bases defaults on trade-weighted EU data excluding EU-origin imports, with a 10% mark-up except for fertilisers. It envisages these values for 2027–2028 and country-specific defaults from 2029. HMRC expressly states that the notices do not currently have legal force; publication is not commencement.[3][4]
Paragraph 11 of Schedule 17 to the Finance Act 2026 authorises Treasury notices setting defaults, including levels designed to remove an advantage from avoiding actual-emissions measurement or verification costs. That statutory power is distinct from a currently operative notice.[5]
Our practical reading is that multinational procurement teams should decide the evidence route before filing. HMRC’s separate emissions-intensity guidance requires a verification report for actual data, identifying both intensity and the calendar-year monitoring period. A supplier estimate without that evidence should not be mistaken for verified actual emissions.[7]
Official sources
- [1] Check the default values for the Carbon Border Adjustment Mechanism
HM Revenue & Customs · Document date: 2026-10-16
Full substantive collection53–93 and all5documentlinks read:16Octoberpublication, alternativeverifiedactualemissions andtCO2e/tonneproductunits. Not all5sectorcommoditytablesreviewed.
- [2] Cement default values
HM Revenue & Customs · Document date: 2026-10-16
Full substantive75–96 including all6cementtable rows read. Regardlessorigin, no laterdefault-to-actualamendment, asymmetricprecursor/finalcombination, 25231000=1.433 and25232900=1.375. Not fullcommoditycensus or nativecalculatoractivation.
- [3] CBAM Default Values Force of Law Notice — Draft
HM Revenue & Customs / HM Treasury · Document date: 2026-10-16
Draftheader/update and fullintroductorymethodology80–89, fullcementtable153–163 read; selectedotherrows visible but not all757lines claimedreviewed. TradeweightedEUdataexcludingEU,10%markupnotfertiliser,2027–28interval/country-specific2029; paragraph11powercrossref. Operativelanguagewithin draft qualified by explicitcollectionnotcommencedstatement.
- [4] CBAM force of law notices and reference document: status and update history
HM Revenue & Customs / HM Treasury · Document date: 2026-07-13
Complete substantive55–128/updatehistory read. Originalpublication13July, material16Octoberupdate/newdefaultnotice;116–118 expresslydraft/no currentforceoflaw/notcommenced/1January2027. publishedOn here denotes evidenced16October materialupdate, not originalfirstpublication.
- [5] Finance Act 2026, Schedule 17 paragraph 11: default values
UK Parliament / The National Archives · Document date: 2026-03-18
Full current-linked paragraph11(1)–(4) read via exactordinarypublicGET20035325bytes afterwebunsupportedXHTML, including geographic/portionvariations and noadvantageincludingverificationcosts. Metadata18March2026 verifiedinHTML. Site no knownoutstandingeffects selectedparagraph, notwholeAct/currentchaincertification. Fullselectedsection148also read, section150identifiedascarbonpricereliefandnotmis-citedasemissions.
- [6] S.I. 2026/995, regulation 4: default values
UK Treasury / HM Revenue & Customs · Document date: 2026-09-08
Full originalregulation4 read via exactordinarypublicGET20026686bytes afterunsupportedXHTML: weight×defaultvalue. Fulloriginalregs1/3/5/7 andintroduction alsoactuallyread from ordinaryexactoriginalURLs; made8September/laid9September/commencement1January2027. Regulation5 includes actualemissionandprecursorconditions; no full17-regulation/exhaustiveamendmentchain claim.
- [7] Getting the emissions intensity when importing CBAM goods
HM Revenue & Customs · Document date: 2026-10-16
Complete substantive73–124 read, formula/defaultoractualalternatives and verificationreportintensity/calendar-yearperiod;2027and2028+monitoringrules/examples. Article confinesclaimtoverificationevidencenotalltimingexamples orliabilitycalculation.