Milestone 16 (M16): Cutover to the new Settlement Timetable

Summary and background

Programme Milestone 16 (M16): Cutover to the new Settlement Timetable, is part of the overall MHHS Programme Delivery Plan which you can find on the Planning page of this website. It is the final Programme Milestone to deliver the Ofgem directed MHHS Target Operating Model (TOM) and MHHS Business Case.  

The M16 objective is to deliver reduced timescales for the Settlement Timetable, from 14 months to four months and the Initial Settlement run (SF) reducing from 15 Working Days (WD) to seven WDs.  

MHHS Programme workstreams were created to support delivery of M16 and the transition to the reduced Settlement Timetable. The MHHS Design Workstream delivered the MHHS Baselined Design Artefacts and Operational Choreography V5.5 which you can find in the Baselined Design Artefacts: Supporting Documents library on this website. The Transition Design Workstream Tranche 2, delivered the Settlement Timetable Transition Design Solution, which reduces the Settlement Timetable in three steps:  

1. From 14 to seven months  
2. From seven to four months  
3. Reduces the Initial Settlement run (SF) from 15 Working Days (WD) to seven WDs

The Settlement Timetable Expert Group (STEG) are tasked with developing and delivering the settlement and migration monitoring, reporting and success criteria to enable appropriate decision-making and to deliver M16 and the Settlement Timetable reductions.

STEG is consulting with industry to ensure that the correct migration and settlement data items are being monitored and reported on, and the success criteria is set correctly. For more information about this consultation, please see the MHHS M16 Settlement Timetable section below.

For more information about STEG activities and the STEG delivery plan please visit the STEG page of this website. 

MHHS M16 Settlement Timetable Consultation 

To support delivery of the Ofgem-directed M16 settlement timetable reduction, STEG has been developing reporting frameworks and success criteria to enable informed decision-making.

The Programme and STEG are seeking input from industry stakeholders to ensure that the proposed reporting and decision criteria are robust and appropriate, ahead of making a recommendation to the Migration & Cutover Advisory Group (MCAG) in June 2026.

This consultation is open for four weeks, and participants have until 17:00 on Tuesday 26 May 2026 to respond.

To view the consultation document and further information, please click on the link below:

Settlement Timetable Consultation on RF Reductions Consultation v1.0

To respond to this consultation, please fill in the M16 Settlement Timetable Consultation Response Form below by Tuesday 26 May 2026:

M16 Settlement Timetable Consultation Response Form

We held a webinar on Wednesday 29 April 2026 to take participants through the history, provide a detailed overview of the M16 approach and delivery process, more information on this consultation and next steps. The webinar materials have been published on the MHHS Webinars & Open Days page of this website

We're also holding three weekly Q&A drop-in sessions to support participants during the consultation period. These are at:

• 12:30-13:00 on Wednesday 6 May 2026 
• 11:00-11:30 on Wednesday 13 May 2026 
• 11:00-11:30 on Wednesday 20 May 2026 

You can submit questions ahead of the Q&A sessions by filling out this question submission form in advance.

We've collated and answered all the questions from the webinar into a central Q&A document which you can view on the MHHS Webinars & Open Days page of this website. The questions and answers from each drop-in session will also be added to this document.

The webinar and drop-in sessions are open to all participants interested in settlement systems or operations.

If you have any questions, please email PMO@mhhsprogramme.co.uk

Detailed M16 and Settlement Timetable Decision Points

The following information sets out the decision choreography of how and when decisions were made to deliver the reduced Settlement Timetable.

1. Elexon lead Design Working Group (DWG) Recommendation
2. Ofgem Directed MHHS Target Operating Model (TOM) and Settlement Timetable Changes
3. MHHS Programme Delivery

1. Elexon lead Design Working Group (DWG) Recommendation

The Design Working Group (DWG) recommended a preferred Target Operating Model (TOM) to Ofgem, which  included a reduction in the timing of the Initial Settlement (SF) Volume Allocation Run (VAR) and the Final Reconciliation (RF) Run.

Click on the link below to view the original recommendation paper:Target Operating Model for MHHS DWG's recommendation to Ofgem

2. Ofgem Directed MHHS Target Operating Model and Settlement Timetable Changes

Ofgem directed the new MHHS TOM which included changes to the Settlement Timetable. You can view these decisions and directions below:

Future enabling the market-wide settlement reform TOM - September 2019

Electricity Retail MHHS: Decision - April 2021

Ofgem Final MHHS decision and Business Case - April 2021

Key Settlement Timetable decision outcomes: 

• Initial settlement run (SF) takes place five to seven working days after the settlement date
• Final settlement run (RF) takes place four months after the settlement date
• Post Final settlement run (DF) takes place 20 months after the settlement date