An update on CP1589 ‘Change the number of characters used to specify Market Participant Role Codes in MDD’

CP1589 ‘Change the number of characters used to specify Market Participant Role Codes in the Market Domain Data’ will now go for decision following the Market-wide Half-Hourly Settlement (MHHS) decision for Change Request (CR) CR041 ‘Change the format of Market Participant Role Code from Char(1) to Char(2)’.

CR041 was issued for impact assessment on 10 January 2024 and will close on 24 January 2024.

What is the status of CP1589? 

The CP1589 consultation closed on 15 December 2023. 17 responses were received to the consultation, 5 of which were confidential. 15 of the responses agreed to the proposed solution of Char (2) for CP1589. The confidential responses were unanimously in support of the proposed solution to CP1589. 

We have engaged with the two respondents that rejected CP1589 to their responses and to understand the rationale for their responses. They did not change their decision, but they do understand that SVG does not require the decision to be unanimous. 

One of the respondents preferred to only make the change once in the MHHS arrangements and not in current arrangements (reject CP1589 but approve CR041).

We believe this would present a risk to the market as we would not be able to allocate any new role codes until the start of MHHS transition.

Moreover, whilst the majority of MDD entities will be superseded by ISD entities at the start of MHHS transition, the MDD Role Code entity will be maintained in parallel with the equivalent entity in ISD during the MHHS transition period – March 2025 to January 2027.

Elexon therefore do not believe this option is practicable or that it adequately addresses the risk of not being able to allocate new Role Codes. 

We presented a verbal update to the SVG at its meeting on 9 January 2024. This included a discussion on the risk that CP1589 seeks to address and the proposed Implementation Date for CP1589.

Elexon believe it is less costly to address the risk than to address it once it has become an issue. We will need to consider the CP1589 Implementation Date in light of the outcome from CR041. 

About CP1589 

The ‘Market Participant Role Code’ data item (J0001 / DI50001) is a single character alphanumeric value (Char(1)) used as a unique identifier for certain Market Roles.

This allows 36 possible Role Codes (26 letters and 10 numbers) to be allocated to different Market Participant Roles, which are defined in the Market Domain Data (MDD).

Currently all 36 of the alphanumeric Role Codes have been allocated.

Although some Role Codes will become available after the end of the MHHS Transition Period, which is scheduled for late 2026 (there is a late transition exit planned for January 2027), it is highly likely that there will be a need for new Role Codes to be allocated before then. 

In order for new Market Roles to be created in the future, a change to the J0001 / DI50001 Data Item is required to increase the number of available Role Codes.

Moving to a two-character alphanumeric value (Char(2)) would provide many new Market Participant Role Codes. Existing single-character Role codes would be unchanged – i.e. would not need to be padded out to two characters or to add a blank before or after the existing character.  

CP1589 considered whether upper and lower case letter should be used instead of moving to Char(2), but the majority of CP1589 responses agreed with Elexon that this would introduce more risk and cost to CP1589. 

Who does CP1589 impact? 

Only those BSC Parties and SVA Party Agents that use the DTN Fixed File Format would need to amend their systems for CP1589 implementation. The Market Domain Data Management (MDDM) system would need to change as Entity 21 ‘Role Code’ will be maintained in MDD until the end of the Transition Period. 

Other existing Market Participants would only need to change their systems if there was a future BSC Modification or Change Proposal that introduced a new Market Participant with a two-character role code that they performed or were required to exchange DTN dataflows with.  

Why did we need to raise a MHHS Change Request? 

If the Market Participant Role Code was changed to ‘Char(2)’ under CP1589, but the MHHS Programme design did not implement an equivalent change at the beginning of the Transition Period, the Market Participant Role Code would revert to Char(1).

This is because the new Industry Standing Data (ISD), which will replace MDD for MHHS, is currently designed with Market Participant Role Code specified as Char(1).  

We raised MHHS Programme CR041 to amend ISD Entity Id 21 ‘Role Code’ from Char(1) to Char(2). As the target implementation date for CP1589 is before MHHS go-live, a MHHS CR is needed to progress the equivalent change to the MHHS design and artefacts.

The MHHS Programme will determine whether this change can be accommodated into MHHS. There is therefore a dependency between CP1589 and CR041.  

The MHHS Design Advisory Group (DAG) agreed to issue CR041 to industry impact assessment at its meeting on 10 January 2024. The DAG will consider the responses to this and whether to approve or reject CR041 at its meeting on 14 February 2024. The SVG will then consider CP1589 at its next available meeting. 

Both CP1589 and MHHS CR041 would need to be approved to allow this Change to be implemented on or before the start of the MHHS Transition Period.  

Get more information 

Further information, including the consultation responses, can be found on the CP1589 webpage.

If you have any questions or would like to discuss this Change Proposal further, please contact Ayo Bammeke on 020 7380 4176 or email [email protected]


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.