SEC v29.0 implemented to extend the SMETS1 TMAD expiry date

21 December 2020

An updated version of the SEC came into effect on 21 December 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).

This is to extend SMETS1 TMAD expiry date from 31 December 2020 to 31 December 2021 to align with the regulatory backstop for all eligible Smart Metering Equipment Technical Specifications 1 (SMETS1) meters to be enrolled or replaced with SMETS2+ meters.

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


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