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
CPM026 Panel Chair and Alternate Implemented 28/08/2020
CPM027/CPW098 Extending the Suspension of Market and Operational Performance Standard Charges due to Covid 19 Implemented 01/06/2020
CPM028 Aligning MOSL Board Governance with the Articles of Association Implemented 01/09/2020
CPM033 Improved process for managing Data Subject Rights Requests Implemented 14/05/2021
CPM034 Retailer Panel Member Changes Implemented 30/11/-0001
CPM036 Provision to vary term of Panel Members Implemented 28/01/2021
CPW047 Enabling Sewerage Wholesalers to create meter networks Implemented 26/07/2019
CPW048 Alternative Payment Terms Implemented 31/01/2019
CPW049 & CPM012 Operational Performance Standards Review Implemented 01/04/2019
CPW050 Changes to the Long Unread Meters Report Implemented 26/07/2019
CPW051 Market Incident Management Plan amendments Implemented 29/03/2019
CPW052 Improving transparency of Alternative Credit Arrangements Implemented 29/03/2019
CPW053 MO Transaction Processing and Reporting Implemented 17/05/2019
CPW054 Housekeeping Changes to Market Codes Implemented 29/03/2019
CPW055 Wholesale Retail Code inconsistency Implemented 28/02/2019

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