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
CPW132 Credit Support and Wholesaler Credit Ratings Raised -
CPM048 & CPW131 Suspending certain MPS charges pending full review of the MPF Raised -
CPM039 & CPW124 Revisions to Panel Composition Implementing 01/09/2021
CPM046 Approved Codes of Practice Design -
CPW120 Final Meter Reads where no Visual Read is available In Consultation 02/12/2022
CPW129 Review of Post RF Materiality Threshold In Consultation -
CPW130 Transfer Read Estimated Reason Codes In Consultation 02/12/2022
CPW128 Updating Volume Validations Tolerance Post-consultation 04/05/2023
CPW085 Premises Vacant transaction link to DPID Post-consultation 02/12/2022
CPW070 & CPM043 Bilateral Interfaces Solution Recommendation 02/02/2022
CPW106 Management of Long-Term Vacant Supply Points Awaiting Ofwat Decision 05/11/2021
CPW122 Introducing Direct Debit as a Payment Method Awaiting Ofwat Decision 28/02/2022
CPM015 & CPW071 Panel self-governance Awaiting Ofwat Decision -
CPW126 Settling of Post RF Primary Charges Awaiting Ofwat Decision 13/05/2022
CPW123 Improved codes for ‘remote read type' Awaiting Implementation 13/05/2022

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