Post-MHHS Full Transition Complete (M15) REC updates
Summary
The REC was updated, primarily through R0209 and R0241, to add requirements that support the transition to, and enduring operation of the MHHS arrangements. As part of the transition, each impacted Metering Point will be migrated using processes defined in Codes, including the REC. Once this migration activity is complete, the legacy and transitional arrangements will become redundant and should be removed from the REC to support its efficient operation
Latest update and next planned activity
Date of latest update
Latest Update
21/07/2026 - On 21 July 2026, the REC Change Panel voted to approve the Change Report (Proposal Plan) for I0325.
Impacts Overview
Impacted REC Parties and Market Participants
AMR Service Provider
Data Aggregator
Data Collector
Data Services
DCC
Distribution Network Operator
Electricity Metering Operative
Energy Supplier
Meter Asset Provider
Meter Operator Agent
Third Party Intermediary
Impacted REC Documents
Schedule 1 - Interpretations and Definitions
Schedule 9 - Qualification and Maintenance
Schedule 12 - Data Access
Schedule 13 - Transfer of Consumer Data
Schedule 14 - Metering Operations
Schedule 15 - Metering Accreditation
Schedule 17 - Secure Data Exchange
Schedule 19 - Market Exit and Supplier of Last Resort
Schedule 23 - Registration Services
Schedule 24 - Switching Data Management
Schedule 25 - Central Switching Service
Schedule 28 - Related Metering Points
Schedule 29 - Address Management
Schedule 30 - Resolution of Consumer Facing Switching and Billing Issues
Impacted REC Services
Central Switching Service (CSS)
Electricity Enquiry Service (EES)
Electricity Retail Data Service (ERDS)
Secure Data Exchange Service (SDES)
Other Industry Codes impacted
Balancing and Settlement Code (BSC)
Data Integration Platform (DIP) Rules
Distribution Connection and Use of System Agreement (DCUSA)
Priority and rationale
High
Priority last updated on 17 Sep 2026
Solution development
Problem Statement
Retention of redundant obligations within the REC would make it more complex to navigate for Market Participants and could cause confusion on the obligations that are in effect to support the efficient operation of the Great British Energy retail market. It is also worth noting that until Ofgem formally closes the MHHS Significant Code Review (SCR), this REC Issue could potentially impact that SCR.
No documents available.
There is currently no Change Plan.
Original submission
Change details
- - -
30 Apr 2026
Change details
Post-MHHS Full Transition Complete (M15) REC updates
The REC was updated, primarily through R0209 and R0241, to add requirements that support the transition to, and enduring operation of the MHHS arrangements. As part of the transition, each impacted Metering Point will be migrated using processes defined in Codes, including the REC. Once this migration activity is complete, the legacy and transitional arrangements will become redundant and should be removed from the REC to support its efficient operation
Retention of redundant obligations within the REC would make it more complex to navigate and could cause confusion on the obligations that are in effect to support the efficient operation of the GB energy retail market.
Review legal drafting in the REC (including Cat 3 documents) to identify what legacy and transitional arrangements should be removed. Determine when any removals should take place, with the expectation that this would be after MHHS Programme Milestone M15 (currently planned for 7 May 2027), taking into account any impacts on other Codes and the provision of REC Services.
It is also recommended that any consequential impacts on REC guidance are identified as part of this review so that this can be coordinated with the implementation of the required REC changes.
It is also recommended that any consequential impacts on REC guidance are identified as part of this review so that this can be coordinated with the implementation of the required REC changes.
The MHHS requirements were included within the REC through a series of modifications. The primary changes were delivered through:
· R0241 - MHHS Incremental Changes for go live
· R0209 - Implementation of Market-wide Half Hourly Settlement (MHHS) Arrangements
The following consequential changes were made to deliver the intent of MHHS:
· R0003 introduced an obligation within the REC for the delivery and implementation of MHHS.
· R0044 and R0097 were implemented at MHHS M8 to introduce the governance for sharing Smart Meter Data Retriever appointment information via the Central Switching Service to the Smart Meter Data Service Provider.
· R0032 and R0066 introduced amended and new MHHS data items into the industry as an enabler in advance of the wider MHHS implementation.
· R0083 was implemented at MHHS M8 to introduce an amended Supply Number format as a consequential change of the removal of some data items from the industry under the MHHS arrangements.
· R0202 was implemented to progress changes to the Performance Assurance Reporting Catalogue to support monitoring of Retail Risks under the transition period and enduring arrangements for MHHS.
· R0208 added the Data Integration Platform to the scope of the Cross Code Steering Group.
Changes to Category 3 documents were implemented through C3-0130, C3-0131, C3-0136, C3-0137, C3-0138, C3-0139 and C3-0089.
· R0241 - MHHS Incremental Changes for go live
· R0209 - Implementation of Market-wide Half Hourly Settlement (MHHS) Arrangements
The following consequential changes were made to deliver the intent of MHHS:
· R0003 introduced an obligation within the REC for the delivery and implementation of MHHS.
· R0044 and R0097 were implemented at MHHS M8 to introduce the governance for sharing Smart Meter Data Retriever appointment information via the Central Switching Service to the Smart Meter Data Service Provider.
· R0032 and R0066 introduced amended and new MHHS data items into the industry as an enabler in advance of the wider MHHS implementation.
· R0083 was implemented at MHHS M8 to introduce an amended Supply Number format as a consequential change of the removal of some data items from the industry under the MHHS arrangements.
· R0202 was implemented to progress changes to the Performance Assurance Reporting Catalogue to support monitoring of Retail Risks under the transition period and enduring arrangements for MHHS.
· R0208 added the Data Integration Platform to the scope of the Cross Code Steering Group.
Changes to Category 3 documents were implemented through C3-0130, C3-0131, C3-0136, C3-0137, C3-0138, C3-0139 and C3-0089.
Impacts
No details provided
Billing accuracy, Trust and confidence
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Schedule 1 - Interpretations and Definitions, Schedule 9 - Qualification and Maintenance, Schedule 12 - Data Access, Schedule 13 - Transfer of Consumer Data, Schedule 14 - Metering Operations, Schedule 15 - Metering Accreditation, Schedule 17 - Secure Data Exchange, Schedule 19 - Market Exit and Supplier of Last Resort, Schedule 23 - Registration Services, Schedule 24 - Switching Data Management, Schedule 25 - Central Switching Service, Schedule 28 - Related Metering Points, Schedule 29 - Address Management, Schedule 30 - Resolution of Consumer Facing Switching and Billing Issues
It is expected that all REC governed documents (including Category 3) will be within scope of this review
No details provided
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Secure Data Exchange Service Definition
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Data Access Matrix, Data Item Catalogue, Market Message Catalogue, Standards Definition
The above noted REC artefacts have, through initial review, been identified as potential candidates for change to remove post MHHS M15 legacy requirements.
It is expected that all REC governed documents (including Category 3) will be within scope of this review.
It is expected that all REC governed documents (including Category 3) will be within scope of this review.
EES API Technical Specification
It is expected that all REC governed documents (including Category 3) will be within scope of this review.
Central Switching Service (CSS), Electricity Retail Data Service, Secure Data Exchange Service
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AMR Service Providers, Data Aggregators, Data Collectors, Data Services, DCC, Distribution Network Operators, Electricity Metering Operative, Energy Suppliers, EES Users, Meter Asset Providers, Meter Operator Agent, Third-Party Intermediary
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Balancing and Settlement Code (BSC), Data Integration Platform (DIP) Rules, Distribution Connection and Use of System Agreement (DCUSA)
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No details provided
Priority & timing
No
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No details provided
Billing accuracy, Trust and confidence