UK Appoints 1 January 2027 for CBAM Late Payment and Repayment Interest Rules

9 september 2026

The UK government has published Statutory Instrument 2026 No. 994, appointing 1 January 2027 as the date on which the Finance Act 2009 interest provisions for late payments and repayments will apply to the UK Carbon Border Adjustment Mechanism (CBAM).

The UK government has published the Finance Act 2009, Sections 101 and 102 (Carbon Border Adjustment Mechanism) (Interest) (Appointed Day) Order 2026 as Statutory Instrument 2026 No. 994 (C. 81).

The Order was made by the Treasury on 8 September 2026 and appoints 1 January 2027 as the date on which sections 101 and 102 of the Finance Act 2009 will apply for the purposes of the UK Carbon Border Adjustment Mechanism (CBAM).

The Order brings the existing Finance Act 2009 interest provisions into effect for CBAM:

  • Late payment interest — Section 101:

    provides for interest on amounts due to HM Revenue and Customs (HMRC) that are paid late.

  • Repayment interest — Section 102:

    provides for interest on amounts that HMRC is required to repay.

The Order also provides for these provisions to apply to penalties assessed in relation to CBAM.

The Order forms part of the UK government's secondary legislation implementing the CBAM, which is scheduled to take effect on 1 January 2027. HMRC's official CBAM collection was updated on 9 September 2026 to include the Interest (Appointed Day) Order among the legislation supporting the mechanism.