On 3 December 2025, DCC submitted to the Department for Energy Security & Net Zero the recommendations for retaining a range of provisions related to SMETS1 enrolment in support of ongoing operation of SMETS1 Devices after enrolment completion.
DCC’s recommendation follows DCC’s consultation, which ran between 17 October 2025 to 14 November 2025, on whether to retain any provisions related to SMETS1 enrolment, by moving those to SEC Appendix AC and SEC Appendix AM. The consultation also sought views on whether to include a previously undocumented SMETS1 Device behaviour into SEC Appendix AM and its Annex A (DMVES Matrix).
Today, 12 December 2025, the Department is re-designating SEC Appendix AC, SEC Appendix AM and SEC Appendix AM Annex A (DMVES Matrix) with the changes, as proposed by DCC.
SEC v126.0 is now live to implement the designated document changes.
To clarify, when DCC’s consultation began, SEC Appendix AC v8.0 and SEC Appendix AM Annex A (DMVES Matrix) v12.4 were in effect. On 6 November 2025, SECAS implemented SEC Appendix AC v9.0 as part of the November 2025 SEC Release.
Changes to SEC Appendix AC required as part of this Designation will therefore uplift Appendix AC to version 10.0.
The changes consulted on as part of the DCC consultation do not overlap with changes made as part of the November 2025 SEC Release.
The change to the DMVES Matrix, which is required as part of this Designation will also uplift the document version number straight to 13.0 for housekeeping purposes with no operational impact.
The documents relating to this Designation can be found here.