P502 Assessment Procedure Consultation Slips Four Months to January 2027 (TBC), Delaying GB Supplier-Aggregator Compensation Timeline

Elexon's updated P502 timetable shows the Assessment Procedure Consultation—previously scheduled for 7-27 September 2026—has been rescheduled to 7-27 January 2027 and is flagged '(TBC)'. The overarching 'Assessment by Workgroup' phase is now listed as running January 2026 through December 2026, extending beyond the three Workgroup meetings already completed (30 January, 26 March and 21 May 2026). Downstream milestones—Assessment Report to Panel (13 May 2027), Report Phase Consultation (17 May-18 June 2027), Draft Modification Report (8 July 2027) and Final Modification Report to Authority (19 July 2027)—remain unchanged.

The four-month slip in the Assessment Procedure Consultation, combined with its tentative 'TBC' status, signals that Elexon's Workgroup has not yet resolved the compensation methodology design issues underpinning P502. Suppliers and Independent Aggregators seeking certainty on how ABSVD-driven Imbalance adjustments will be redistributed must now wait longer for consultation input, while the fixed May-July 2027 report-phase dates imply Elexon intends to compress the remaining process once the consultation concludes, raising execution risk for the stated Final Modification Report target.

The rescheduling, rather than cancellation, of the Assessment Procedure Consultation suggests the Workgroup requires additional time to converge on the compensation mechanism's mechanics—likely reflecting the complexity of allocating financial impact between Suppliers and Independent Aggregators fairly. Notably, the downstream milestones (Assessment Report, Report Phase Consultation, Draft and Final Modification Reports) are still shown at their original 2027 dates despite the consultation delay, which may indicate either confidence that the slip won't cascade or an as-yet-unrevised placeholder timetable that could itself shift once the January 2027 consultation outcome is known. This pattern—extended Workgroup assessment with a 'TBC' consultation window—is consistent with other complex BSC modifications addressing aggregator-related settlement questions, and warrants monitoring for further timetable revisions before the stated May 2027 Assessment Report date.

Balancing and Settlement Code (BSC)

Assessment Procedure Consultation closes (rescheduled, TBC) · 27 Jan 2027

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