Changes to the SEC version approach

13 February 2020

What changes are going to take place?

Each SEC Section and Subsidiary Document will be given their own individual version numbers, which will simplify the version control of the SEC. This change will be effective from the February 2020 SEC Release on 27 February 2020.


Why are we making changes to the SEC version approach?

The SEC is currently made up of around 80 separate documents, split across Sections, Schedules and Appendices. To date, the Code has been treated as a single document with a single version number. Each document is therefore updated to a new version in each release, even if there is no impact on that particular document. This makes tracking the history of specific documents difficult for Parties when change takes place.


What will happen next?

The SEC Sections and Schedules which currently don’t have individual version numbers will be set to v7.0 (the next integer version). The Appendices, which have individual version numbers, will be set to the next integer version (e.g. a document currently at v1.2 will be set to v2.0).

Each time we update the SEC, only the documents being updated will increase in version number by an integer value (e.g. 8.0, 9.0 etc). Decimal versions (e.g. 7.1, 7.2 etc) will be used for draft versions published on our website ahead of implementation.


Why is this beneficial to you?

Our new approach will make it easier for you to see what has changed between versions of a document and track its history. This will particularly help within CodeWorks, where all historic versions of individual documents will be available, and you can compare the changes between the current and any historic version.


Are there any parts of the SEC the new approach won’t apply to?

To be clear, this new approach will NOT apply to:

  • The GB Companion Specification (GBCS) (Schedule 8)
  • The Smart Metering Equipment Technical Specifications (SMETS) (Schedule 9)
  • The Communications Hub Technical Specifications (CHTS) (Schedule 10)
  • The DCC User Interface Specification (DUIS) (Appendix AD)
  • The Message Mapping Catalogue (MMC) (Appendix AF)

The current version numbering approach for these documents will be left as-is.

We are working on improvements to the applicability tables and the compatibility matrix to make these clearer to Parties and will communicate improvements in due course.


If you have any questions or want any further information on any of this, please call our helpdesk at 020 7090 7755 or email