Market Domain Data


Market Domain Data (MDD) is the central repository of reference data used by Suppliers, Supplier Agents and Licensed Distribution System Operators (LDSOs) in the retail electricity market. It is essential to the operation of Supplier Volume Allocation (SVA) Trading Arrangements. 

MDD is produced by the Supplier Volume Allocation Agent (SVAA) in the form of Data Transfer Network (DTN) flows D0269 (Market Domain Data Complete Set) and D0270 (Market Domain Data Incremental Set).

Latest updates

The MDD Circulars page gives you the latest updates of proposed and confirmed changes to Market Domain Data.. If you would like to be notified by email when a circular is published, please email the MDD Co-ordinator

We issue two Circulars during each MDD Release:

  • Impact Assessment Circular: informs you of the proposed changes to be included in the next Version of MDD. A copy of all the proposed changes are attached to the Circular, and you are expected to carry out an impact assessment on these changes.
  • Final Circular: confirms the changes being committed to the next Version of MDD. Once the Final Circular is issued, changes cannot be excluded from that Version.

MDD Release Schedule

The MDD Release Schedule shows the Change Request submission deadlines, Publish date and Go-Live date for each Version of MDD.

How to get MDD data

MDD Online

Market Domain Data is available at MDD Online on the BSC Portal (login required). The MDD content also features ad-hoc reports that may help you operationally.

  • BSC Portal > Operational Data > Market Domain Data (MDD)

Access to MDD files

The data is public but non-BSC participants will require consent from Elexon to receive files containing regression data.

To obtain consent, fill in the form below and submit it via the BSC Service Desk webform. Once the team have received the form they will validate the details and proceed with adding you to the distribution as per the request.

Receiving MDD files

You can nominate to receive MDD files via the DTN or email. Please let the SVAA know by emailing the BSC Service Desk stating which files you would like to receive and how you would like to receive them.

You will receive the files for the next Version of MDD on the MDD Publish date. If you do not receive these or you have any issues with the files then please contact the BSC Service Desk.

Changing data in MDD

Market Participants can submit requests to include or amend the data in MDD for information relating to their own Market Participant ID (MPID). These are submitted using the relevant Entity Forms, along with a BSCP509/01 Cover Form.

These forms will need to be submitted by email to the MDD Co-ordinator. These must be with us by the deadline for the Version of MDD you want the changes to be included in – please see the MDD Release Schedule for a list of these dates.

BSCP509 Appendix 2 provides guidance on the how to complete MDD Change Request forms and shows how the validation process works. The MDD Entity Links Map helps identify the relationships between Entity Forms; this can be found at the bottom of this page.

Changes to MDD initiated by Ofgem Review

There will be an increase in MDD sets in response to Ofgem’s Targeted Charging Review (TCR). The TCR means major changes to how network charges are set. It will see the numbers of Line Loss Factor Class (LLFCs) information in MDD increasing on a large scale, as well as the number of valid set combinations. 

Find out more about the changes and how this impacts you.

MDD Load Utility

We offer an MS Access tool which allows you to manipulate your MDD files for reporting purposes.

You can download a copy from the zip folders below. Please select the correct folder depending on which version of the MDD files you receive.


Click on the X next to any of the icons to replace them with a short-cut link to the page you are currently on or search for a specific page.