Current Status: Rejected
This Modification was rejected by the Authority on 15th April 2026.
Summary of Modification
This enabling Modification seeks to align the IGT UNC with UNC Modification 0843. It will
require that the IGT UNC places an obligation on IGT UNC Parties to:
- Comply with the Independent Shrinkage Expert (ISE) as stipulated within the Independent Gas Transporters Arrangements Document (IGTAD); and
- Not unreasonably withhold data where such data is requested by the ISE for use in the Independent Shrinkage Model Methodology (ISMM).
Progression Timetable
| Initial consideration by Workgroup | 8th June 2023 |
| Amended Modification considered by Workgroup | 13th July 2023 |
| Workgroup Report presented to Panel | 30th May 2025 |
| Draft Modification Report issued for consultation | 20th June 2025 |
| Consultation close-out date | 11th July 2025 |
| Final Modification Report available for Panel | 18th July 2025 |
| Modification Panel Decision | 29th August 2025 |
| Submitted to the Authority | 3rd September 2025 |
| Authority determination received | 15th April 2026 |
| Document | Description | Document Type | Author | Date |
| IGT165 | Authority Decision Analysis Report | Adobe PDF | Ofgem | 15/04/2026 |
| IGT165 | Authority Decision Letter | Adobe PDF | Ofgem | 15/04/2026 |
| IGT165 | Final Legal Text (v1.0) | Adobe PDF | Code Administrator | 03/09/2025 |
| IGT165 | Final Modification Report (v1.0) | Adobe PDF | Code Administrator | 03/09/2025 |
| IGT165 | Final Modification Report (v0.2, Code Administrator email updated) | Adobe PDF | Code Administrator | 04/08/2025 |
| IGT165 | Final Modification Report (v0.1) | Adobe PDF | Code Administrator | 30/07/2025 |
| IGT165 | Draft Legal Text (v0.4, Clean) | Adobe PDF | Code Administrator | 31/07/2025 |
| IGT165 | Draft Legal Text (v0.4 Tracked from v0.3) | Adobe PDF | Code Administrator | 31/07/2025 |
| IGT165 | Consultation Response (BUUK) | Adobe PDF | BUUK | 25/07/2025 |
| IGT165 | Consultation Response (E.ON) | Adobe PDF | E.ON | 25/07/2025 |
| IGT165 | Consultation Response (ES Pipelines) | Adobe PDF | ES Pipelines | 25/07/2025 |
| IGT165 | Consultation Response (Indigo) | Adobe PDF | Indigo | 25/07/2025 |
| IGT165 | Consultation Response (NESO) | Adobe PDF | NESO | 25/07/2025 |
| IGT165 | Draft Modification Report (v1.0) | Adobe PDF | Code Administrator | 19/06/2025 |
| IGT165 | Draft Legal Text (v0.3, Clean) | Adobe PDF | Code Administrator | 03/04/2025 |
| IGT165 | Draft Legal Text (v0.3, Tracked from v0.2) | Adobe PDF | Code Administrator | 03/04/2025 |
| IGT165 | Draft Modification Report (v0.1) | Adobe PDF | Code Administrator | 22/05/2025 |
| IGT165 | Final Workgroup Report (v1.0) | Adobe PDF | Code Administrator | 22/05/2025 |
| IGT165 | Draft Workgroup Report (v0.3, Clean) | Adobe PDF | Code Administrator | 30/04/2025 |
| IGT165 | Draft Workgroup Report (v0.3, Tracked) | Adobe PDF | Code Administrator | 30/04/2025 |
| IGT165 | Draft Workgroup Report (v0.2 Clean) | Adobe PDF | Code Administrator | 03/04/2025 |
| IGT165 | Draft Workgroup Report (v0.2, Tracked) | Adobe PDF | Code Administrator | 03/04/2025 |
| IGT165 | Draft Legal Text (v2.0) | Adobe PDF | Code Administrator | 27/02/2025 |
| IGT165 | Draft Workgroup Report (V0.1) | Adobe PDF | Code Administrator | 27/02/2025 |
| IGT165 | Draft Legal Text (V1.0) | Adobe PDF | Code Administrator | 06/02/2025 |
| IGT165 | ROM Response (Clean) | Adobe PDF | CDSP | 02/05/2024 |
| IGT165 | ROM Response (Tracked) | Adobe PDF | CDSP | 02/05/2024 |
| IGT165 | Amended Modification Proposal (v2.0, Clean) | Adobe PDF | OVO | 06/07/2023 |
| IGT165 | Amended Modification Proposal (v2.0, Tracked) | Adobe PDF | OVO | 06/07/2023 |
| IGT165 | Modification Proposal (v1.0) | Adobe PDF | OVO | 19/05/2023 |