Red-lined Design Artefacts: Interim Release 5, 5.1, 5.2, 5.3, 5.4 and 5.5
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 They are retained for historical reference only.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Documents are now the single source of truth, and any changes made through Code governance will not appear in the historical documents.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.
The Red-lined Design Artefacts for Interim Release 5, 5.1, 5.2, 5.3, 5.4 and 5.5 are available in the respective libraries below.
The Programme has now baselined Interim Release 5 of the Design Artefacts. Clean versions of these Artefacts are published in the respective libraries on the Baselined Design Artefacts page of this website.
We have published the Artefacts in their own libraries to support participant engagement with the Artefacts.
Interim Release 5.5
On 3 April 2024, the Programme published Interim Release 5.5 Design Artefacts.
Interim Release 5.5 incorporates changes to Swagger.
Full details of the issues addressed are covered in the Release Note below:
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Physical interfaces - Real Common Blocks - json | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Interfaces Event Codes - json | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Data Types - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical Interfaces - Real Common Blocks - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Data Catalogue - json | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Interfaces Event Codes - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Data Catalogue - yaml | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Data Types - json | E2E003 | Technical Design | Approved | v1.5.5 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.5 |
Interim Release 5.4
On 7 February 2024, the Programme published Interim Release 5.4 Design Artefacts.
Interim Release 5.4 incorporates changes to Swagger and the DES-138 Interface Catalogue.
Full details of the issues addressed are covered in the Release Note below:
Release Note for Interim Release 5.4
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Physical interfaces - Response Codes - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Real Common Blocks - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical Interfaces - Real Common Blocks - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - ECS Reports - yaml | E2E003 | Technical Design | Approved | v1.5 |
| Physical interfaces - Data Types - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Interface Catalogue (redlined) | DES138 | Interface Specifications | Approved | v5.5.5 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Response Codes - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.3 |
| Physical interfaces - Data Types - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Interfaces Event Codes - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Interfaces Event Codes - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Data Catalogue - json | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - ECS Reports - json | E2E003 | Technical Design | Approved | v1.5 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.3 |
| Physical interfaces - Data Catalogue - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.4 |
Interim Release 5.3
On 17 January 2024, the Programme published Interim Release 5.3 Design Artefacts.
Interim Release 5.3 incorporates changes to Swagger and the E2E001 End to End Solution Architecture document.
Full details of the issues addressed are covered in the Release Note below:
Release Note for Interim Release 5.3
Red-lined Design Artefacts: Interim Release 5.3
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Data Catalogue - json | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Interfaces - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.6 |
| Physical interfaces - Data Catalogue - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Real Common Blocks - json | E2E003 | Technical Design | Approved | v1.5.3 |
| End to End Solution Architecture (redlined) | E2E001 | Technical Design | Approved | v3.5.2 |
| Physical interfaces - Data Types - json | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Interfaces - json | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.6 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical interfaces - Data Types - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
| Physical Interfaces - Real Common Blocks - yaml | E2E003 | Technical Design | Approved | v1.5.3 |
Interim Release 5.2
On 13 December 2023, the Programme published Interim Release 5.2 Design Artefacts.
Interim Release 5.2 incorporates changes to address Swagger and DES138 Interface Catalogue alignment.
Full details of the issues addressed are covered in the Release Note below:
Release Note for Interim Release 5.2
Red-lined Design Artefacts: Interim Release 5.2
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.5 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.5 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Data Catalogue - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Interface Catalogue (redlined) | DES138 | Interface Specifications | Approved | v5.5.4 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Data Types - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
| End to End Solution Architecture | E2E001 | Technical Design | Approved | v3.5.1 |
| Physical interfaces - Data Types - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Data Catalogue - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Interfaces - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Real Common Blocks - json | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical Interfaces - Real Common Blocks - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
| Physical interfaces - Interfaces - yaml | E2E003 | Technical Design | Approved | v1.5.2 |
Interim Release 5.1
On 17 October 2023, the Programme published Interim Release 5.1 Design Artefacts.
Interim Release 5.1 incorporates changes to address Swagger and DES138 Interface Catalogue alignment.
Full details of the issues addressed are covered in the Release Note below:
Red-lined Design Artefacts: Interim Release 5.1
| Short Name | Doc Number | Sub Type | Status | Version |
|---|---|---|---|---|
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.3 |
| Physical Interfaces - Real Common Blocks - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Real Common Blocks - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Submit Events - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Data Catalogue - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Submit Events - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Interfaces - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Interfaces - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Examples | E2E003 | Technical Design | Approved | v0.3 |
| Interface Catalogue (redlined) | DES138 | Interface Specifications | Approved | v5.5.3 |
| Physical interfaces - Data Types - json | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Data Types - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
| Physical interfaces - Data Catalogue - yaml | E2E003 | Technical Design | Approved | v1.5.1 |
