CLAF Resettlement Tariff Year 2025/26
Affected Period
Status
Closed
Category
Balancing
Run Type
Created
Last Updated
Dear Market Participant,
SEMO was previously notified by the System Operators and Regulatory Authorities of an issue relating to the calculation of Transmission Loss Adjustment Factors (TLAFs) under Section F.4.2 of the Trading and Settlement Code.
Following review, it was determined that the original Version 1 TLAF values, which were subsequently used in the derivation of Combined Loss Adjustment Factors (CLAFs) submitted to the Market Operator, may not have reflected the intended calculation methodology. As a result, the System Operators undertook a Version 2 recalculation and consideration was given to whether those revised Version 2 CLAF values should be resubmitted to SEMO for application in the resettlement of Tariff Year 2025/26 (1st of October 2025 to 30th of September 2026).
Over recent weeks, extensive engagement has taken place between the System Operators, Regulatory Authorities, SEMO and industry participants while the matter was under consideration.
The Regulatory Authorities have since issued correspondence on the 22nd and 23rd of October 2026 to both the System Operators and SEMO. This correspondence directs that the necessary steps be taken to ensure that Version 2 TLAFs, and the associated Version 2 CLAFs, are not applied as part of any current resettlement activity for Tariff Year 2025/26. This direction has been issued to facilitate further consideration and confirmation of the appropriate approach for the 2025/26 Tariff Year.
SEMO would also like to emphasise that Market Participants retain the ability to raise Settlement Queries, in accordance with Section G.3 of the Trading and Settlement Code, regarding any issues or concerns identified within the Tariff Year 2025/26 resettlement publications, notwithstanding the direction issued by the Regulatory Authorities.
Kind regards,
SEMO