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
CPW029 & CPM007 GDPR and Data Protection Provisions Updates Implemented 30/03/2018
CPW030 Review of Market Performance Standards Implemented 01/04/2018
CPW031 Extending the new connection suspension period Implemented 03/03/2018
CPW032 Amend H/04 to clarify Tariff effective date Implemented 28/09/2018
CPW033 Meter effective to date field in MDS_METER report Implemented 26/10/2018
CPW034 Housekeeping changes to CSD 0301 Implemented 25/05/2018
CPW035 F01 Form Amendments Implemented 28/09/2018
CPW036 G/02 Form Amendments and G/03 Temporary Consent Form Implemented 28/09/2018
CPW037 Removing the Error Codes list from CSD 0301 Implemented 28/09/2018
CPW038 Tariffs Report updates Implemented 17/05/2019
CPW039 & DCP002 Deferral of Final Settlement Runs Implemented 31/08/2018
CPW040 Changes to the contents of the NAPS Report Implemented 17/05/2019
CPW041 G read removal governance Implemented 29/03/2019
CPW042 Provision of adding re–read flag into the MDS Meter Reads file Implemented 17/05/2019
CPW043 Drafting clarifications for CPW028 Implemented 26/10/2018

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