Elexon's Dedicated P521 Tracking Page Confirms Full Report Phase Timetable, Resolving Prior Ambiguity on Panel/Authority Dates

Unlike the immediately prior tracked source (a standalone Report Phase Consultation notice page that repeated only the 22 September–22 October 2026 consultation window without restating downstream dates), this new source is Elexon's dedicated P521 modification tracking page. It explicitly restates the full Report Phase timetable, including the previously 'unconfirmed-by-this-document' dates: Present Draft Modification Report to Panel (12 November 2026) and Issue Final Modification Report to Authority (13 November 2026), alongside the Initial Written Assessment date (10 September 2026) and the consultation window (22 September–22 October 2026). It also adds new provenance detail: the proposer (BW ESS) and the original submission date (3 September 2026).

This source resolves the tracking gap flagged in the prior event: stakeholders no longer need to rely solely on an older document for the Panel and Authority reporting dates, since Elexon's own modification tracker now corroborates that the 12-13 November 2026 dates remain intact and unchanged. This strengthens confidence in the Report Phase timeline for generators, route-to-market providers and optimisers assessing when the Lead Party nomination flexibility might be implemented, while the underlying mechanism and consultation deadline remain unchanged.

This appears to be the authoritative, continuously-updated Elexon modification page rather than a static consultation notice, and its restatement of the complete timetable should be read as confirmation rather than new substantive development. No design mechanism, scope, or stakeholder impact has changed. Analysts should treat this as closing the informational gap identified in the prior tracked update rather than as a market-moving event; the core open item remains the 22 October 2026 response deadline and the subsequent Panel/Authority steps in mid-November 2026.

Balancing and Settlement Code (BSC)

P521 Report Phase Consultation response deadline (closes 5pm) · 22 Oct 2026

Primary sources