CMP453: To Bill BSUoS on a net basis at BSC Trading Units
What is being proposed
The move to gross billing of BSUoS means that customers forming part of a BSC Trading Unit are paying BSUoS when the net flows at the point of connection are exports, so the customers are not using the system and should not pay BSUoS.
Current status
Proposal raised on 30 April and will be presented to Panel on 23 May. On 23 May the Panel by majority agreed that CMP453 should follow the Standard governance route and proceed to a Workgroup. On 26 September 2025 The Panel agreed with the revised timeline for CMP453. The Panel also agreed that the Terms of Reference have been met and agreed for CMP453 to proceed to Code Administrator Consultation. The Code Administrator Consultation will be published on 29 September, and this will close on 20 October 2025. (06/11/2025) At the CUSC Panel On 31 October 2025 the Panel recommended by majority that the Proposer’s solution better facilitates the CUSC Applicable Objectives. The Final Modification Report will be sent to Ofgem on 11 November 2025.
Details
Timeline
Analysis
CMP453 proposes to charge BSUoS on net rather than gross flows for BSC Trading Units, meaning customers who export more than they import would not pay system balancing costs. The CUSC Panel recommended the change by majority on 31 October 2025, with the Final Modification Report sent to Ofgem on 11 November 2025. The modification follows Standard Governance through a Workgroup process.
Why it matters
The change realigns cost incidence with system use — exporters would no longer subsidise balancing services they do not consume. As such, this shifts costs from behind-the-meter generators and storage operators to net importers, creating a cleaner price signal for grid utilisation.
Key facts
- •Panel recommendation by majority on 31 October 2025
- •Final Modification Report sent to Ofgem on 11 November 2025
- •Applies to BSC Trading Units with net export flows
- •Medium impact on customers and suppliers