Change

As the market operator, MOSL manages changes to the Market Arrangements Code (MAC) and Wholesale Retail Code (WRC) on behalf of the non-household market. Anybody can propose a change to the codes provided it passes the Initial Acceptance Criteria, which are applied by the market operator, and the Acceptance & Prioritisation Criteria, which are applied by the Code Change Committee. MOSL supports proposers to develop proposals for acceptance and if accepted to develop solutions for recommendation to Ofwat for approval. MOSL may also propose its own changes and solutions.

This page provides information on past and current changes. Please use the links to the right for consultations on current changes, guidance on the change process and how to propose a change. MOSL also provides the Code Change Committee with a monthly report describing the progress of each change proposal and anticipated releases of changes to the codes and central systems. The latest report can be downloaded from the link on the right. Previous reports can be found in Code Change Committee papers.

Consultations Pipeline Changes Non-Code Change Requests Change Report Proposing a Change Guidance on Engagement

Change Proposals

The Change Register below shows all proposals that have been formally submitted which have been accepted or will be assessed by the Code Change Committee for acceptance into the change process. Changes to the Market Arrangements Code are prefixed CPM and changes to the Wholesale Retail Code are prefixed CPW. Some changes impact both codes.

Following the implementation of CPM053 on 18 December 2023, formally submitted changes that fail the Initial Acceptance Criteria applied by the Market Operator will not be assessed by the Code Change Committee. These pipeline changes are prefixed by PIP and will be published on this website in due course.

By default, the table below sorts changes by where they are in the process with those in the early stages at the top and those implemented, rejected or withdrawn at the end. Clicking the table headings sorts by reference, title, status or implementation date. The filters can be used to search for a specific change, status or implementation date. If a change has multiple parts with different statuses then its status will be 'See Change Summary'. A summary of each change and documentation associated with it can be viewed by clicking on the change title link within the table.

Change Register

Reference	Title	Status	Implementation date
CPM061 & CPW158	Data/Report Release to Public Bodies	Initial Assessment
CPW139 & CPM051	Bilateral Hub	See change summary
CPM058 & CPW149	Market Performance Framework Reform	See change summary	01/04/2025
CPM052 & CPW140	BR-MeX (business customer and retailer measure of experience)	Design	01/04/2025
CPW155	Data Quality Assurance Flags	Design
CPW157	Data Retention Beyond Seven Years	Design
CPM060 & CPW156	Customer and Third-Party Access to Consumption Data	Design
CPM054 & CPW145	Deductions and withholdings under formal Disputes Process	Consulting
CPW154	Interim Supply: Initial Cost Support	Consulting
CPW153	Interim Supply: Cost Recovery Mechanism	Consulting
CPW152	Post-RF customer refunds	Post Consultation
CPW132	Credit Support and Wholesaler Credit Ratings	Ofwat Decision
CPW142	Wholesaler Smart Meter Reads	Ofwat Decision
CPW001	Cross Border Matters	Implemented	02/10/2017
CPW002	CSD0301 Updates - Meter Treatment	Implemented	02/10/2017
CPW003	CSD0301 Updates - Meter Networks	Implemented	02/10/2017
CPW004	CSD0301 Updates - Meter Networks (Future)	Implemented	02/10/2017
CPW005	Self Supply	Implemented	03/07/2017
CPW006	CSD0301 - New data item updates	Implemented	02/10/2017
CPW007	Alignment to Customer Protection Code of Practice	Implemented	02/10/2017
CPW008	Direction to Supply	Implemented	02/10/2017
CPW009	CSD 0302 updates - alignment with CSD 0301	Implemented	02/10/2017
CPW010	Emergency Contact Details	Implemented	28/09/2018
CPW014	CSD 0301 Updates	Implemented	18/05/2018
CPW015	CSD 0101 Clarification	Implemented	02/10/2017
CPW016	CSD0104 Clarification – Meter Networks	Implemented	02/10/2017
CPW017	CSD0105 Clarifications and updates	Implemented	02/10/2017
CPW018	Clarification of Unsecured Credit Allowance	Implemented	23/04/2018
CPW019	Alternative Eligible Credit Support	Implemented	31/07/2018
CPW020	Proposal to amend the wording in the F02 Complaint Form	Implemented	01/12/2017
CPW021	Negotiating Alternative Eligible Credit Support reasonably and in good faith	Implemented	14/07/2017
CPW022	New Connection Retailer Unknown	Implemented	18/05/2018
CPW023	Market Entry and Re-Assurance Updates	Implemented	12/03/2018
CPW024	Settlement Renaming and Report Issuing Updates	Implemented	01/12/2017
CPW025	Extending TCORR Functionality for Inactive Data Items	Implemented	17/05/2019
CPW026	Removing SPID version design	Implemented	28/09/2018
CPW027	QC Error Code	Implemented	18/05/2018
CPW028	Unpaired SPIDs	Implemented	28/09/2018
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
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
CPW070 & CPM043	Bilateral Transactions	Implemented	29/11/2022
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
CPW083	Vacancy Incentive Scheme	Implemented	15/05/2020
CPW084	Introducing a Retailer Measure of Experience (R-MeX).	Implemented	01/04/2020
CPW085	Premises Vacant transaction link to DPID	Implemented	29/11/2022
CPW087	Ability for Wholesalers to add meter reads	Implemented	06/11/2020
CPW089	T101 Adding Billing Address fields	Implemented	14/05/2021
CPW091	Temporary Changes to Vacancy	Implemented	30/03/2020
CPW092/CPM029	Unified Disputes Process and Committee	Implemented	13/11/2020
CPW093	Payment deferral interim measures	Implemented	30/03/2020
CPW094	Temporary Change to Disconnections	Implemented	08/04/2020
CPW095	Urgent: Maintain Credit Requirements	Implemented	16/04/2020
CPW096	Urgent: Payment Deferral Medium Term	Implemented	01/05/2020
CPW099	Clarify the responsibilities of Trading Parties during a planned event	Implemented	14/05/2021
CPW101/CPM031	Unwinding Temporary Covid-19 Arrangements in the Business Retail Market	Implemented	01/08/2020
CPW102/CPM030	Gender Neutrality in the Market Codes	Implemented	06/11/2020
CPW103/CPM032	Interim Supply Process Amendments	Implemented	09/09/2020
CPW104	Housekeeping changes to facilitate the Performance Regime introduced in April 2020	Implemented	15/02/2021
CPW105	Provisions of Information Obligation	Implemented	26/08/2022
CPW107	Covid-19 Temporary Vacancy exemptions for Credit Support	Implemented	23/10/2020
CPW108	Agreement to Unplanned Settlement Runs	Implemented	26/01/2021
CPW109	Changing the Constraints on Customer Reads	Implemented	09/07/2021
CPW111	Housekeeping change to align the codes with CMOS	Implemented	14/05/2021
CPW112	Clarifications to CSD 0102 and CSD 0105	Implemented	14/05/2021
CPW113	Housekeeping Changes to Correct Typographical Errors and Enhance Standardisation	Implemented	14/05/2021
CPW114/CPM037	Housekeeping Changes to Correct Typographical Errors and Enhance Standardisation	Implemented	14/05/2021
CPW116 & CPM038	Clarification and removal of redundant clauses in the Unified Disputes Process	Implemented	01/09/2021
CPW117	Shortening the late payment default timeline for a credit support reduction	Implemented	05/11/2021
ICP/WRC003	Alignment with Exit Regulations	Implemented	02/10/2017
ICP/WRC036	Data Format Updates	Implemented	02/10/2017
ICP/WRC048	Tariff Table Updates	Implemented	02/10/2017
ICP/WRC051	Performance Charge Alignment with ISA	Implemented	02/10/2017
ICP/WRC053	SPID Pairing Updates	Implemented	02/10/2017
ICP/WRC055	Trade Effluent Updates - SVAM Subtract and Calculated Discharge Frequency	Implemented	02/10/2017
ICP/WRC059	Settlement Updates	Implemented	02/10/2017
CPM001	Change Proposal Form Update	Implemented	03/07/2017
CPM003	Revised MIMP Committee Composition	Implemented	01/12/2017
CPM004	Board Nomination Process Extension	Implemented	15/09/2017
CPM006	Introducing a process for Urgent Change Proposals	Implemented	08/04/2020
CPM008	Redistribution of Market Performance Standards Charges	Implemented	29/03/2019
CPM009	Further Board Nomination Process Extension	Implemented	16/03/2018
CPM010	Amendments to the Retailer Board Nomination Process	Implemented	31/07/2018
CPM011	MOSL invoices and payment terms	Implemented	31/07/2018
CPM013	Adding the Customer Representative as a Voting Panel Member	Implemented	20/09/2019
CPM014	Market Performance Standards Charges Redistribution Payment Clarification	Implemented	26/07/2019
CPM016	Panel Voting Majorities	Implemented	23/08/2019
CPM018	Treatment of Market Performance Standard charges and Operational Performance Standard charges	Implemented	01/01/2020
CPM019	GDPR Data Security Standards	Implemented	06/11/2020
CPM022	Urgent Change: Reducing Panel Quorum	Implemented	07/10/2020
CPM023/CPW090	Suspension of Performance Standard Charges	Implemented	23/03/2020
CPM024	Urgent housekeeping alignment of CPM020 with CPM023	Implemented	01/04/2020
CPM025/CPW097	Suspension of Market Performance Standard Charges following an interim supply event	Implemented	01/07/2020
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	01/02/2021
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
CPW056	Cascade Erasure	Implemented	08/11/2019
CPW057	Improving transparency of Credit Guarantee Arrangements	Implemented	30/09/2019
CPW058	Removing Processes A1-A5 (Developer Services)	Implemented	26/07/2019
CPW059	Changes to Review Obligations	Implemented	15/02/2021
CPW060	Clarifying credit scores and ratings for the purposes of Unsecured Credit Allowances	Implemented	30/09/2019
CPW119 & CPM042	Dormant Trading Party Provisions	Implemented	05/11/2021
CPW120	Final Meter Reads where no Visual Read is available	Implemented	12/05/2023
CPM039 & CPW124	Revisions to Panel Composition	Implemented	01/09/2021
CPM040 & CPW121	MAC and WRC Principles	Implemented	01/09/2021
CPW123	Improved codes for ‘remote read type'	Implemented	13/05/2022
CPM044	Management of the Ofwat Innovation Fund	Implemented	17/11/2021
CPW126	Settling of Post RF Primary Charges	Implemented	26/08/2022
CPM045 & CPW127	Extending the right of the Market Operator to raise Change Proposals	Implemented	14/01/2022
CPW128	Updating Volume Validations Tolerance	Implemented	12/05/2023
CPM047	Change to Panel Quorum	Implemented	14/01/2022
CPW130	Transfer Read Estimated Reason Codes	Implemented	12/05/2023
CPW134	Clarifications to default provisions	Implemented	02/08/2022
CPW135	CPW135 WRC Housekeeping	Implemented	29/11/2022
CPM049	MAC Housekeeping	Implemented	03/03/2023
CPM050	Data Cleanse Funding	Implemented	22/05/2023
CPW136	Drawing credit following Retailer exit	Implemented	07/04/2023
CPW137	Interim Supply: Customer Data Provisions	Implemented	27/10/2023
CPW138	Housekeeping changes post CPW070 & CPM043	Implemented	20/06/2023
CPW141	Clarification of read definitions and meter chamber ownership	Implemented	16/02/2024
CPW143	Wholesaler Maintenance of YVEs for Non Market Meters	Implemented	10/05/2024
CPW144	Market Performance Framework Incremental Improvements	Implemented	18/12/2023
CPM053 & CPW146	Change Process Improvements	Implemented	18/12/2023
CPM055	CMOS Data Escrow	Implemented	16/02/2024
CPW147	MPS18 & 19 clarification	Implemented	18/01/2024
CPM056	Resource support to industry groups	Implemented	04/04/2024
CPM057	Late Payment of MO Charges	Implemented	04/04/2024
CPW148	Transfer Read Notifications for Outgoing Retailers	Implemented	06/12/2024
CPW150	Governance of Incentive Scheme Guidance Documents	Implemented	08/11/2024
CPM059	MAC & MOSL Articles Duplication	Implemented	06/12/2024
CPW151	WRC Housekeeping	Implemented	08/11/2024
CPW012	Flags on D1 Disaggregated Settlement Report	Rejected
CPW013	Meter Reading Validation	Rejected
CPW069	Right of a Retailer to appoint an Accredited Entity to repair or replace a faulty meter when a Wholesaler misses the associated SLA	Rejected
CPW075	Settlement Estimation - Remove estimated meter readings when forward estimating	Rejected
CPW080	Simplification of the Default and Termination Process	Rejected
CPW086	Unsecured Credit Allowance – Rebalancing	Rejected
CPW088	Ability for Wholesalers and Retailers to add Meter Location Data, and GIS X/Y Details.	Rejected
CPW100	Urgent: Revision to Credit Support Requirement under CPW095	Rejected
CPW110 & CPM041	Sharing Non-Household Emergency Contact Details	Rejected
CPW115	Amending and updating the definition of Insolvency Event to remove the ‘negative net assets’ criterion	Rejected
CPM015 & CPW071	Panel self-governance	Rejected
CPM021 & CPW125	Panel Membership and Voting Rights	Rejected
CPM035	Panel Election Streamlining	Rejected
CPW061	Unsecured Credit Allowance reflecting payment history	Rejected
CPW062	Household Indicator Flag	Rejected
CPW118	Minimum Meter Read Frequency	Rejected	13/05/2022
CPW122	Introducing Direct Debit as a Payment Method	Rejected
CPM046 and CPW133	Approved Codes of Practice	Rejected
CPW129	Review of Post RF Materiality Threshold	Rejected
CPM048 & CPW131	Suspending certain MPS charges pending full review of the MPF	Rejected
CPW011	New Read Type D3010	Withdrawn
CPW063	Chargeable Data - Fixed RTS	Withdrawn
CPW067	Bulk Submission of Service Requests via MS Excel	Withdrawn
CPW076	Change to the current KPI for CSD002 OPS Measure C1a	Withdrawn
CPW106	Management of Long-Term Vacant Supply Points	Withdrawn
CPM005	Market Entry and Re-Assurance Updates	Withdrawn