SEC v25.0 implemented for CoS Minimising Dormancy and SMETS1 Core Uplift 1.2

12 November 2020

An updated version of the SEC came into effect on 12 November 2020 to implement a modification to SEC Appendix AL ‘SMETS1 Transition and Migration Approach Document’ (SMETS1 TMAD) made by the Department for Business, Energy and Industrial Strategy (BEIS).

The BEIS designation letter and accompanying annexes which include the redlining can be found here.

This letter constitutes the Government’s response to two consultations undertaken by the Data Communications Company (DCC) on behalf of BEIS and a direction to re-designate the SMETS1 TMAD:


What parts of the SEC were affected?

  • SEC Appendix AL ‘SMETS1 Transition and Migration Approach Document’


Our Document Log lists the versions of each SEC document now in effect following this release.

You can download the individual SEC documents from the SEC and Supporting Documents section of our website or via CodeWorks.


Where can I find further information?

If you have any questions, you can call the SECAS Helpdesk at 020 7090 7755 or email