P520 Balancing and Settlement Code (BSC) proposed changes
- Publication type:
- Code modification
- Publication date:
- Topic:
- Energy codes,
- Electricity supply
- Subtopic:
- Balancing and settlement code (BSC),
- Market-wide half-hourly settlement (MHHS)
Outcome of proposed changes to Balancing and Settlement Code, P520 Update the Manifest Errors Process to align with revised MHHS Settlement Timetable.
Details of outcome
On 12 October 2026, the Final Modification Report for BSC modification proposal P520 was submitted to Ofgem for decision. We have decided to approve this proposal.
Start date
The proposal will be implemented on 25 February 2027.
Code modification description
A Manifest Error Claim is the mechanism through which a Party may seek correction of an obvious pricing error in an accepted Balancing Mechanism Bid or Offer. Where a claim is upheld by the BSC Panel, the relevant Bid or Offer price may be amended for Settlement purposes, helping to avoid unfair Settlement outcomes arising from clear pricing errors. Under the current arrangements, the BSC Panel is required, wherever practicable, to consider a Manifest Error Claim in time for any resulting adjustments to be applied in the Initial Settlement Run (SF).
When this requirement was introduced, the Settlement timetable provided sufficient time for claims to progress before SF was completed. Under MHHS, the Settlement timetable will be significantly shortened. As part of this, the SF deadline will be reduced to 7 Working Days and the First Reconciliation Run (R1) deadline will be reduced to 30 Working Days after the Settlement Day. These changes are scheduled to take effect on 2 July 2027 in accordance with Milestone M16 of the MHHS Implementation Plan. This will reduce the time for Settlement processing and associated governance activities, including assessing any Manifest Error Claims. This modification requires the BSC Panel, wherever practicable, to consider a Manifest Error Claim in time to apply any adjustments in the R1 Run.