HMRC Releases Comprehensive MRV Technical Guidance for UK CBAM, Opens Feedback Window

HM Revenue & Customs (HMRC) has published its foundational "Technical guidance for monitoring, verifying and reporting emissions" for the UK Carbon Border Adjustment Mechanism (CBAM).

The extensive 313-page technical guide outlines the specific rules, supporting information, and procedural workflows necessary for tracking actual emissions under the UK framework. The document explicitly targets three key stakeholder groups in the compliance chain:

• Overseas installation operators who must monitor the CBAM emissions data at the site of production.

• Independent verifiers tasked with auditing and verifying these CBAM emissions.

• UK importers (liable persons) responsible for reporting these actual emissions accurately on their CBAM returns.

Importantly, HMRC is treating this publication as an iterative document and is actively seeking industry input before the definitive regime begins:

"We’re still working to improve this content and will be updating the guidance as necessary to reflect further technical analysis and stakeholder feedback. On or before 13 November 2026, you can send technical feedback on this guidance to cbampolicyteam@hmrc.gov.uk, with ‘MRV technical guidance feedback’ in the subject line."

HMRC has stated that all technical feedback received will be reviewed, and the agency may execute further updates to the guidance prior to the January 1, 2027 launch date. Importers and their overseas supply chain partners are highly encouraged to review the methodologies immediately to identify any operational gaps.