MOSL manages changes to the Market Arrangements Code (MAC) and Wholesale Retail Code (WRC) on behalf of the non-household market. Changes can be proposed by any industry participant and MOSL supports proposers to design and develop proposals prior to Panel review and Ofwat determination whether to implement the proposal. This page provides information on current changes, how to engage with the change process and how to propose new changes.

MOSL prepares a change report for the Panel each month describing the progress of each change proposal and the anticipated implementation programme.  The current change report can be downloaded from the link on the right.  Previous reports can be downloaded in the Panel papers.

MOSL may consult on behalf of the Panel to gather evidence on the need for and impact of a change proposal. Input from market participants and customers is welcomed and live consultations can be accessed through the link on the right.

If you wish to raise a change please follow the link on the right which provides templates and contact details to submit changes.

The Change Register below shows all proposals that have been formally submitted to change the Market Arrangements Code (prefixed CPM) or Wholesale Retail Code (prefixed CPW). Please use the filter and sort functions to navigate past and current changes and click on a change to view the documents associated with it.

Change Register

Reference Title Status Implementation date
CPW044 Digital Certificates & Public Keys updates Implemented 03/12/2018
CPW045 Updates to the Service Management Interface Implemented 03/12/2018
CPW046 Changes to the unplanned settlement process Implemented 03/12/2018
CPW064 Changes to Corrective Settlement Runs for Individual Supply Points Implemented 14/02/2020
CPW065 Retailer Notifications Implemented 15/05/2020
CPW066 Estimation Review Implemented 14/02/2020
CPW068 & CPM017 Market Incident Management Plan Committee Revisions Implemented 28/08/2020
CPW072 Setting MPS 15 charges to zero Implemented 01/11/2019
CPW073 Updates to GDPR Personal Data Warnings in CSD 0301 Implemented 14/02/2020
CPW074 Introduction of a Retailer SLA in relation submission of trade effluent market forms to Wholesalers. Implemented 28/08/2020
CPW077 Establishing Trade Effluent charging strength methodology Implemented 06/11/2020
CPW078/CPM020 Priority Performance Regime Changes for April 2020 Implemented 01/04/2020
CPW079 Protections for Credit Support Security Implemented 14/02/2020
CPW081 Improving transparency of Alternative Payment Terms Implemented 01/04/2020
CPW082 Gap Site Incentive Scheme Implemented 01/04/2020

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