Hunch. The 2 December deadline is 49 days after the 14 October draft. All six selected comparable annual rounds reached their final decisions within 49 days.
The 2 December market resolves on Ofwat's page of yearly decisions on penalties and rewards (in-period outcome delivery incentive determinations) at ofwat.gov.uk, which blocks automated readers and must be opened by hand: YES if a final determination for 2025-26 with sums by company is published by the end of 2 December 2026, and NO if it is not. Reports in The Guardian and BBC News of the final decision confirm it, and settle it if the Ofwat page cannot be read.
We examined six selected dedicated annual in-period ODI draft/final rounds from 2016 to 2023. All six reached final determination within 49 days and by 15 December. Substantive changes exceeding £1m are documented in 2022 and 2023; the available evidence does not establish a complete change rate.