REC MHHS training event: insights and next steps

A: Access to the EES Sandbox is available to existing EES users only. This is due to the database being populated with production data. Any EES user will be able to provide software providers etc. with access through their API key as per the production environment.

A: Change Issues Group (CHIG), first Thursday of every month.

A: The redlined changes to reflect approved REC CP R0121, which was in the MHHS Metering Operations Schedule, did not include the relevant SDEP names. These will be added into the MHHS baseline when available through the implementation of CP R0121 and, therefore, are not required within I0241.

A: All updated REC Schedules are redlined, except the Metering Operations Schedule due to fundamental structural change and the Migration Schedule as it’s new. These can be found on the REC MHHS Release wiki page of the REC Portal and the MHHS Programme website.

A: Yes, the change freeze is applicable to all codes. It was formalised by the Programme Steering Group and has been in place since 6 December 2023.

A: There are currently no MHHS Programme On-hold CRs allocated to the REC. This may change if ownership of the SSC transfers from BSC to REC, and we will liaise with the Proposer to understand any urgent concerns.

A: Yes, the same cross-code process will apply, and this is already in place. DIP flow changes, similarly to DTN flow changes, are led by the relevant Code with ownership of that message. The DIP Manager will be looped in via CCSG and engaged in the change process.

A: Yes, Swagger will continue to be maintained by the DIP Manager and is expected to align with the Energy Market Data Specification.

A: R0202 sets out the expected updates to the Performance Assurance Report Catalogue (PARC) for Performance Assurance monitoring under the MHHS arrangements. This is currently with the DIP Manager to confirm they can provide the reports we have requested within the PARC. Once this change is approved and the test data available, we will develop the metrics and update the Retail Risk Register. The Early Life Support Model being developed by the MHHS Programme will also give Parties visibility of the proposed metrics.

A: Yes, the readiness assertion is for all participants as it covers changes required under the REC which are outside the scope of MHHS Qualification, such as the changes to legacy role requirements and Supply Number Format, etc.

A: Within section 7.3.2 of the Qualification Approach and Plan v4, this is scheduled for July-August 2025. We will accept electronic sign off and delegation of authority in line with the Maintenance of Qualification practice. Further details will be communicated to Parties in the next few months.

A: For Metering Points created pre-M10, the existing DTN messages will be sent to the Supplier on Initial Registration, i.e. D0217 and not the D0260. MHHS Qualified Suppliers will also receive an IF002 so they can decide whether to migrate the metering points.

For Metering Points created post-M10, they will be created as MHHS Metering Points. Where the initial registration is progressed by an MHHS Qualified Supplier, only the IF002 will be issued and no DTN messages (D0217).

For Metering Points created post M10, they will be created as MHHS Metering Points. Where the initial registration is progressed by a Non MHHS Qualified Supplier, only the D0217 will be received. This is subject to a Programme PPIR to provide clarity on the New Connection process.

A: Yes, for Metering Points in the Advanced Segment. Smart Metering Assets can have separate Data Services, so these won’t be auto-aligned for Metering Points in the Smart Segment.

A: The auto alignment of MOAs applies where an Import/Export Association has been established within SMRS, in accordance with the BSC. Where an Import Export Association has not been established (for example, if there is a separate/standalone export meter) then separate MOAs can be appointed.

A: The MTC will continue to be available for Non MHHS Metering Points but will cease to be present once a metering point is migrated to MHHS.

A: MDD will be frozen for 5 years from M10. Where a table appears in both MDD and ISD changes made to ISD tables will mean that the data sets will no longer align.

A: A REC CP (R0243) has been raised to transfer the ownership of the SSC data item from the BSC to REC ownership. Should this CP be approved we plan to consider the optionality of the SSC through a future REC Issue.

A: All existing SSCs will be retained in the Meter Configuration Table maintained under the REC.

A: Yes, the MHHS Flag is a requirement being tested through SIT Migration. 
In addition, the EES API Sandbox is available for testing by EES Users. Participants who would like access to the MHHS EES API Sandbox should contact the EES Service Provider at support@candc-uk.com.

A: Yes, that’s correct. Legacy information not part of the MHHS data set will not be displayed against an MHHS-migrated MPAN.

A: No, these are set out as separate data items.

A: This is being discussed through the MHHS Programme’s migration framework. The question of Complex MPANs is due to be addressed in the next consultation. Also, a workshop on the migration framework design, open to all participants, is scheduled for 4 March 2025.

A: No, until M14 Reverse Migration can take effect. There is no requirement for Suppliers to communicate either reverse of forward migration to Customers. It is recognised that in the non-domestic market there is a potential for the migration to impact contracts, in which case a communication to the customer would be required. Ofgem is considering guidance around this point.

A: These items will be available for all traditional meter assets and for Smart and Advanced Metering Points if they have been populated by the Supplier.

A: No, once a supplier is MHHS Qualified and effective within ISD they cannot choose to Reverse Migrate. Following MHHS Qualification a Supplier will go through Service Activation, which includes agreement of a Migration Plan with the MHHS Programme and confirmation that they are able to appoint MHHS Qualified Supplier Agents before they are made effective in ISD.

A: The CSS DPI will be available via the EES for all MPANs, and the MPAN Designation will be removed.

A: There shouldn’t be any impact on the customer other than the normal switch between Suppliers.

A: The Cumulative Register Reading is the sum of the individual Time of Use Register Readings. Currently, all NHH meters are settled using the active Time of Use register readings. Post-MHHS, Smart Meters will be settled using the Total Cumulative register reading, regardless of how many Time of Use registers are active for billing purposes. This means the Switch/CoS reading used between Suppliers, for smart meters, will always be the Total Cumulative register reading for MHHS Migrated Metering Points.

A: Yes, if legacy messages (e.g. D0312) are sent to SMRS during MHHS Migration, these will be rejected using a new rejection code.

A: The DUoS Tariff ID and LLFC ID are used for similar purposes and can match. However, these are separate data items and can have different values depending on the mapping adopted by the DNO.

A: Yes, there is no change to the application as set out in the Registration Services Schedule.

A: New DTN flows are live in the DTN and can be used with test flags. This includes new scenario variants created to reflect the new market roles.

A: The D0311 requires the losing Supplier to provide the active Time of Use registers and the Total Cumulative register for the smart meter. In this case, the losing Supplier should provide the meter readings for both ToU Register 1 and the Total Cumulative Register. Both would have a TPR of 1 but would be distinguished by the Register ID.

A: The reverse migration design takes into account that some required legacy data items won’t be populated for MHHS-migrated Metering Points. These items should be populated by a Supplier during the COS process. Where this hasn’t happened, they will revert to the last items held within SMRS.

A: Meter Technical Details are shared via a number of Market Messages: IF005 for all Metering Assets; and additionally D0149 / D0150 for Traditional Metering Assets and D0268 for Advance Metering Asset. The data items included in these messages are set out in the MHHS Energy Market Data Specification to be implemented at M8.

A: The majority of documents and information relating to REC impacts can be found on the REC Portal in the MHHS Hub in the Knowledge Centre. Links to the approved code drafting can be found in the REC Release for MHHS Milestone 8 article. We will provide a one-off full list in the MHHS bulletin as a reminder next week.

A: Please email MHHSPAF@Elexon.co.uk to join the Working Group, where these subjects are discussed on a monthly basis. The 25/26 BSC Audit scope will be published in April following comment and approval by the BSC PAB. This will detail work papers in scope.

A: The QAD includes guidance against each question to clarify the Code Bodies’ expectations. Additionally, the comments raised during the Initial QAD review will be specific to allow the Party to ensure their Final QAD included the required level of detail. Please also refer to the QAD Walkthrough Webinar for further guidance on the level of information required for different questions. Furthermore, each month at the Qualification Working Group, we will share key lessons learnt from QAD reviews that have already been completed. Qualification Assessment Document and MHHS Webinars & Open Days – MHHS Programme.

A: Suppliers that do not qualify in MHHS will be subject to measures described within Qualification Approach & Plan (QA&P) Annex 4. In effect they will not be able to onboard new Metering Points. Ofgem is also considering incentives in relation to this. MOAs that are not MHHS Qualified cannot be appointed to Metering Points after M14.

A: Yes, we have a flexible resource model in place with regular checkpoints so that we can learn from our experience and adjust/re-forecast as needed.

A: Thank you for flagging this. Please refer to the latest version of the Qualification Approach & Plan for the latest approved dates. The slides have been updated for circulation.

A: We are adding questions to the QAD to ask Parties to demonstrate the controls they will operate to ensure they meet the conditions of an exemption. The updated QAD has been issued for consultation on 12 February 2025 and will be taken through the governance process for approval after the consultation closes. Please note that the additional questions will only apply to Parties seeking an exemption.

A: After MHHS Qualification, Parties will need to disclose changes they are making as per the existing Change and Incident Notification process under the REC. As guidance, in general you are required to disclose changes if they may impact your ability or other Market Participant’s ability to meet REC obligations. We will review these on a case-by-case basis to determine the extent of assurance activities required.

A: We, along with BSCCo, are taking guidance for Parties to the Qualification Working Group to highlight common observations from the QAD submissions. We will also update the QAD FAQ document published on the MHHS collaboration base where required.

A: Your OAMs will continue to support you with queries related to the REC. Additionally, we advise Parties to send queries specific to their organisation to the REC Service Desk, and the relevant Qualification team member will engage with you.

A: Parties can choose to resubmit and go through multiple rounds of comments or request a bilateral meeting, if required. However, the team will try to ensure that the feedback is clear, so Parties understand the changes they need to make.