The Central Market Operating System (CMOS) is the core IT system for the non-household market. CMOS manages all the electronic transactions involved in switching customers and provides water usage and settlement data. MOSL, in partnership with CGI, are continually working to improve CMOS operations. Here you’ll find MOSL’s release plans, outlining future functionality.

CMOS – Next Release

CMOS – Current Release

CMOS Maintenance Schedule 2022


Release Schedule 2022 - 2023


Error Codes


CMOS 12.0 Release Note


CMOS – Previous Release

Error Codes


CMOS 11 Release Notes


Tariff Data Upload Guidance 2021-2022


Non Code Change NCC Request Guidance


Data Management

Maximum number of transactions to be submitted into CMOS


Staff Data Protection Training Policy


Security Incidents and Breaches Policy


Defect Management

ALM Observations (Defect Log)


CMOS Administration

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CMOS, MO Portal and Bilaterals hub Access Proforma

FTP automated reports folder structure

ITSM Browser Settings - Recommendations

MO Portal User Guide

Agreement Management (Wholesale) Guidance Note

FTP Reporting Login Instructions

NCC Change Request Template

Non-Code Change (NCC) Request Guidance

Recreating Supply Points Following Erroneous Deregistration

SPID Flows Tradability

Tariff Data Upload Guidance 2022-2023

Guidance for Final meter read following Change of Use

MVI Batch Template

CMOS Training Videos

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CMOS General Training - Wholesaler

CMOS General Training - Retailer

Reporting Overview

CMOS Training Documents

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Content Outline Interface (Retail)

CMOS 3.0 Reporting User Manual

Remedy Service Management Interface

Reporting Overview training slides

Reporting Training Course Schedule

Reporting Training Presentation slides

Reporting Training Student Workbook

Viewing and Creating Agreements in CMOS

CMOS 11.0 Wholesaler User Manual

CMOS 11.0 Retailer User Manual

Content Outline Interface (Wholesale)

MOSL Guidance

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Submitting an Unplanned Settlement Run Request

Non-code change requests

View CMOS-impacting change requests here.

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Operations and Release Working Group (ORWG)

The latest outputs from the ORWG.

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CMOS – Release archive

Error Codes


XSD Updates for CMOS Release 10.0


XSD for CMOS Release 10.0


CMOS 10.0 Release Notes 1.22


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