Migration Design
Please note that as of 1 September 2025, the MHHS Programme Design mailbox, Design artefacts and the Design Issues Notification (DIN) log on the MHHS website are no longer monitored or updated. They are retained for historical reference only.
Following Milestone 8 (M8), the Target Operating Model (TOM) and MHHS Design were fully codified, and the Code Bodies no longer maintain standalone Programme artefacts. The live Code and Code Subsidiary Documents are now the single source of truth, and any changes made through Code governance will not appear in the historical documents.
You can view the latest artefacts online, directly from the respective Code Bodies websites, listed below:
Balancing & Settlement Code (BSC)
Retail Energy Code (REC)
Distribution Connection and Use of System Agreement (DCUSA)
For the latest information or to raise queries, please use the Elexon Support Portal or contact the respective Code Bodies directly.
Here you can find the baselined Migration Design Artefacts.
The Artefacts below articulate the technical process through which Meter Point Administration Numbers (MPANs) will be migrated from legacy arrangements to the new MHHS arrangements, and in the case of Reverse Migration, back to the legacy arrangements from MHHS arrangements.
Migration Design Artefacts Baselined
The Migration Design Artefacts were baselined following approval at the extraordinary Design Advisory Group (DAG), on 31 March 2023.
Since then, the Programme has processed Design Issue Notifications (DINs) raised by Programme participants. These are published in the Design Issue Notification (DIN) Log, published on the Design Review Process page of this website.
Following review of the DIN Log by the Design Team, several Design Artefacts are being updated with red-lined changes for participant review. The Programme is publishing the Red-lined Design Artefacts through six Interim Releases, following the Design Review Process.
The Red-lined Design Artefacts and accompanying Release Notes can be found on the Red-lined Design Artefacts page of this website.
The Migration Design was created in collaboration with industry through the Migration Design Subgroup (MDSG).
If you have any questions on the Artefacts or wish to discuss Migration Design in more detail, please contact Migration@mhhsprogramme.co.uk
Migration Design Artefacts
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Change of Supply - Reverse Migration | DEL-971 | Business Process Descriptions | Draft | v1.2 |
| Migration Design Requirements Log | DEL974 | Business Requirements | Draft | v1.2 |
| Change of Service - Metering Service - Forward Migration | DEL969 | Business Process Descriptions | Approved | v1.2 |
| Change of Service - Data Service - Reverse Migration | DEL973 | Business Process Descriptions | Approved | v1.0 |
| Migration Design Document | DEL961 | Unclassified | Draft | v1.5 |
| Change of Service - Metering Service - Reverse Migration | DEL-972 | Business Process Descriptions | Approved | v1.0 |
| Change of Service - Metering Service - Reverse Migration | DEL-966 | Business Process Descriptions | Approved | v1.0 |
| Change of Service - Data Service - Reverse Migration | DEL967 | Business Process Descriptions | Approved | v1.0 |
| Change of Supply - Forward Migration | DEL962 | Business Process Descriptions | Draft | v1.2 |
| Change of Supply - Reverse Migration | DEL-965 | Unclassified | Approved | v1.0 |
| Migration Design Document (REDLINED) | DEL961 | Unclassified | Draft | v1.5 |
| Change of Supply - Forward Migration | DEL-968 | Unclassified | Approved | v1.0 |
| Change of Service - Data Service - Reverse Migration | DEL967 | Business Process Diagrams | Approved | v1.1 |
| Change of Service - Metering Service - Forward Migration | DEL963 | Business Process Diagrams | Approved | v1.4 |
| Change of Service - Data Service - Forward Migration | DEL970 | Business Process Descriptions | Approved | v1.1 |
| Change of Service - Data Service - Forward Migration | DEL964 | Business Process Diagrams | Approved | V1.4 |
| Change of Supply - Reverse Migration | DEL-965 | Business Process Diagrams | Approved | v1.2 |
