FAQs

MOSL is a member owned company, limited by guarantee. This means it is owned by it's members, which are the trading parties. Changes to our constitution, and approval of our annual budget, are therefore voted on by our members at a General Meeting.

MOSL is a member owned company, limited by guarantee. This means it is owned by it's members, which are the trading parties. Changes to our constitution, and approval of our annual budget, are therefore voted on by our members at a General Meeting.

Click here for an explanation of the non-household market and our role as market operator. You can also complete our market training.

You can also find lots of general information and support via Ofwat's Business Retail Market webpage and the Open Water website. If you would like provided complaint support and guidance, please visit CCW's Business Customer Hub.

The page here lists any pending General Meeting, along with details of recent General Meetings. Your contract manager will also have received notice of any General Meeting, including our Annual General Meeting (AGM).

MOSL is a member owned company, limited by guarantee. This means it is owned by it's members, which are the trading parties. Changes to our constitution, and approval of our annual budget, are therefore voted on by our members at a General Meeting.

'Bilateral transaction' is a complicated-sounding term for something that is, in essence, very simple.

In the non-household water market, retailers ‘own’ the relationship with customers. The retailer is responsible for the quality of service that a customer receives and nearly all communications with them.

The water itself is supplied - and taken away - by one of 26 regional wholesalers, who own the water and water infrastructure. They also own and maintain customers’ water meters. However, in the non-household market, wholesalers only contact customers directly in certain circumstances, e.g. if their water supply is cut off unexpectedly (i.e. there is an ‘unplanned outage’).

When serving their customers, retailers often need to liaise with wholesalers to get a particular job done, such as fixing a water meter. There is therefore a two-way – or ‘bilateral’ – relationship.

Each request, instruction or process update that passes between the retailer and wholesaler is referred to as a 'bilateral transaction.’ Each process often involves multiple bilateral transactions.

These bilateral transactions normally take place behind the scenes, without the customer needing or wanting to be aware – they should just happen. The customer usually only becomes aware of the interplay between wholesalers and retailer when something doesn’t go to plan.

Progress on our business plan commitments is published on a quarterly basis through our business plan and Key Performance Indicator (KPI) reports. You can view the quarterly reports here.

This information can be found on our Market Improvement page.

 Please contact us via the Contact us page. Select 'press / media' as the subject and submit your question.

Progress on our business plan commitments is communicated through our business plan and KPI quarterly reports. They can be found on our Business Planning page.

You can access information on our business plan commitments here.

For any connectivity issues to CMOS, please raise a ticket, as per the details above in the service desk section.

Yes, while trading parties are responsible for managing their own IP addresses, MOSL may supply a list of IP addresses whitelisted for that trading party.

Trading parties can request IP whitelisting via email to itsupport@mosl.co.uk stating the environment. The request needs to be approved by the Contract Manager, Deputy Contract Manager or Authorised user.

These requests can take up to 5 business days to process.

Trading parties can request IP whitelisting or IP blacklisting via email to itsupport@mosl.co.uk stating the environment. The request needs to be approved by the Contract Manager, Deputy Contract Manager or Authorised user.

These requests can take up to 5 business days to process.

You must submit all the relevant information within the proforma to itsupport@mosl.co.uk well in advance of the expiry date as these requests can take up to 5 business days to process. Trading Parties are responsible for monitoring the expiry date of their certificates.

If you need a specific report, a quote can be requested via itsupport@mosl.co.uk detailing your requirements, including the data items required, time period for the data, if the report is a one-time only or the frequency of the report required. Do I have to pay for an ad hoc report?

Yes, any reports that the Market Operator is not required to provide as per Market Codes will be chargeable. A quote will be provided to the Trading Party to confirm the request or not. Trading Parties may submit requests to the Market Design team via codechange@mosl.co.uk to check if the report can be beneficial for all trading parties and added to the Market Codes.

Yes, trading parties may download the ‘Reporting Training Student Workbook’ and Reporting User Manual on our webpage under CMOS Training Documents. Visit the CMOS page here.

Yes, CMOS users have access to the Report section to create ad hoc reports. The Reporting User Manual provides a guide for creating reports. This link can be found on via CMOS Homepage> Reports > Reports> User-defined Reports

Adaptations can be made to the report. However, any report that is listed within CSD0302 will need a code change, when changes are required. If you need a specific report, a quote can be requested via itsupport@mosl.co.uk detailing your requirements, including the data items required, time period for the data, if the report is a one-time only or the frequency of the report required.

• LVI user only - CMOS Homepage> Reports > Reports
• FTP – Trading Parties can download the reports via this link where they will have access to their reports.

For existing trading parties, you will need to contact your CMOS admins to unblock admin accounts. As a last resort, you can contact the Service Desk on MOSLservicedesk.uk@cgi.com or phone 0333 207 6589

For existing trading parties, you will need to contact your CMOS admins to set up CMOS accounts.

On the MOSL website, we have guidance documents and training videos that cover CMOS usage and how a trading party may interact with the system. 

Once the Strategic Panel has been appointed, it will confirm the criteria and process for Code Change Committee Member appointments which will be published on this webpage.  MOSL will provide Trading Parties with notice of the Strategic Panel Meeting at which candidates will be considered.  At the same time it will invite Trading Parties to nominate candidates no later than 5 Business Days before the meeting.

MOSL is responsible for implementing, maintaining, and monitoring the service, incentivising data quality improvement and ensuring data quality targets are being met.

As part of this, MOSL is available to providing ongoing support to trading parties.

If you have a query, please raise a query to IT Support via My MOSL.

The Data Assurance Service is a multi-phase assurance programme which will take place across a number of years. The timeline of each phase is dependent on its complexity and will be reviewed before implementation to ensure the commitment from trading parties is reasonable and achievable. The indicative timeline for 2023/24 can be found here.

The first data drop for the Market Eligibility Assurance phase of the programme will take place on 22 November 2023, with data provided to trading parties monthly following this date. The full process is outlined in the specification document, which is available in the Key Documents section.

From 22 November, trading parties will have 12 months to review and assure or de-register their 'level 1' supply points provided by MOSL. Level 1 supply points are defined as those that have the highest match against multiple external data source indicators, suggesting that it holds a household status and is therefore ineglible for the non-household market. 

The first and second year of the Data Assurance Service (2023-25) is being funded through Market Operator (MO) charges to wholesalers only – this includes third party costs and MOSL research.

Cost for future years’ will be determined in collaboration with trading parties – it is important to note that this method of funding is by no means creating a precedent for other MOSL activities to be funded solely by wholesalers. 

The goals for year one of the service are: 

• To develop and implement an assurance service for eligibility, address, and premises (including a small-scale pilot for Customer and Occupancy management)
• For trading parties to review and cleanse high-confidence ineligible premises (expected to be circa 100,000 supply points)
• For trading parties to review and cleanse a sample of high-confidence address/premises issues across a number of use cases (expected to be circa 6,000 supply points in total)
• To assess the veracity and value of a central assessment and cleanse service for each use case, refining the business case for consideration in 2024/25 (as part of business planning)
• To develop a data quality scorecard and define data quality performance metrics that will inform a reformed Market Performance Framework (MPF).

In collaboration with a data services provider and market-led working group, MOSL will deliver a centrally supported data assurance service to enable trading parties to improve and maintain their data held in CMOS.

MOSL will be responsible for implementing, maintaining, and monitoring the service, incentivising data quality improvement and ensuring data quality targets are being met.

Trading parties will remain the data owners and will be responsible for making the appropriate changes to their data in CMOS.

Through our position at the centre of the non-household market, MOSL has a unique opportunity to drive centralised change to improve the quality of data it holds in CMOS. Accurate and reliable data is critical to an effective operation of the market.

Responding to this, as well as member feedback, MOSL committed to delivering a data cleanse plan for core market items, and issued a Request for Information (RFI) in October 2020 to seek input from trading parties on the costs and challenges of managing poor quality data. In April 2022, Project TIDE (Transformation in Data Enrichment) was established to look at how data quality could be improved. Our data services partner, Sagacity, undertook a Data Quality Assessment to investigate the extent of the issues in the market. The results of this were shared with the market, and were used as part of the consultation for a Central Data Cleanse consultation in November 2022.

The deregistration of a supply point happens when a premises has a record in CMOS that should not exist or is no longer valid. This deregistration may or may not require physical disconnection activity.

When an eligible premises has changed use, i.e. it has been converted into a domestic premises, the supply point will need to have an end date on it to reflect it is no longer in the market. If the premises was registered in error, i.e. it is a household customer that should not have been entered on CMOS, the supply point will need to be 'erased' from CMOS.

If there is no longer a supply point at the premises, i.e. a permanent physical disconnection has already taken place, it will also need to be updated in CMOS. These updates are reflected by the wholesaler deregistering the supply point due to the different reasons above.

As per section 9.10.1 of Schedule 1, Part 2 of the Wholesale-Retail Code, a Contracting Wholesaler should notify the Authority (notifications@ofwat.gov.uk), the Water Industry Commision for Scotland (competitionteam@watercommision.co.uk) and the Market Operator (operations@mosl.co.uk) within 2 Business Days of becoming aware a payment failure

Market Entry Assurance provides MOSL and other trading parties with assurance that you can uphold your market obligations and ultimately participate in the market. It also fulfils two Trading Conditions.

Market Entry Assurance Testing (MEAT) involves two stages; Interface and Data Transaction Testing (IDTT) and Market Scenario Testing (MST). IDTT is designed to ensure your company’s systems can interact with the CMOS, whereas MST provides a series of business scenarios to ensure your systems can complete common system transactions. For more information on MEAT, see the MEAT plan. 

We strongly encourage applicants to complete their MEA Testing within a 10-day window. However, if you are unable to complete testing within this timeframe, it can be extended. 

Material changes are any changes made by a trading party which affects the way they uphold their market obligations.

The third party report should include your company’s approach to completing the Business Solution Assessment, and should assure the outcomes of the assurance undertaken. If you consider some statements to carry a higher level of risk, you may consider it appropriate for the third party report to provide assurance on these statements as well.

No. You only need to complete all scenarios if you plan to use all transactions in the High-Volume Interface (HVI). If you only plan to use the HVI for select transactions, you only need to complete scenarios in which these transactions feature. 

MOSL will provide test data for new entrants who need to complete MEA testing.

MOSL has not specified the level of detail required, as it differs between applicants and depends on individual circumstances. We are happy to review drafts and answer questions before you submit final versions. Please contact us for more information.

The documents should be signed by someone with authority to sign on behalf of your company.

MOSL does not charge for applicants to undergo MEA.

There are two routes applicants can take to complete MEA; self-certification and enhanced. Applicants with small scale operations, mostly manual processes, and who intend to only use the Low Volume Interface (LVI) in CMOS can go through self-certification. This is considered the ‘light-touch’ route. All other applicants must go through the enhanced certification route, which involves providing more in-depth assurance to MOSL and undergoing testing of the company’s systems. 

Each MEA document will ask for different types of information, and will explain what you are expected to provide. While supporting documents such as process maps or policies are not required, you can submit these if you feel they will help MOSL to better understand your company’s capability. 

Most applicants take between 40-60 business days to complete the Market Entry Assurance process, depending on whether they go through self-certification or enhanced certification.

If a wholesaler chooses to terminate its contract with a retailer, an interim supply process will be used to allocate the customers to a new licensee (new retailer), but only for the wholesale area for which the contract was terminated. If the retailer has customers in other wholesale areas, the retailer can continue to operate as normal in those areas.

If a retailer exits the market through insolvency or through licence revocation by Ofwat, an interim supply process is used to allocate the customers in all wholesale areas to a new licensee (new retailer).

Other than notifying MOSL if a retailer becomes subject to an insolvency event, the wholesaler has very limited involvement in the Interim Supply Allocation exercise. Once the interim supply points have been allocated to retailers, the relevant wholesaler(s) may need to complete actions in accordance with CSD 0102: ‘Registration: Transfers’ and CSD 0202: ‘Meter Read Submission: Process’, in order to make the supply point(s) tradable.

There are two different methods of allocation which may be used for an interim supply event:

1. Ofwat will instruct MOSL to use the allocation process within CMOS, which will allocate the supply points between retailers with an active opt in agreements. In this process, the supply points may be allocated to a number of retailers
2. Ofwat may choose to utilise the tender process, through which retailers are required to provide Ofwat with commercial information. Ofwat will then make an assessment on the retailer deemed the most appropriate for the supply points to be allocated to. In this process, the supply points will only be allocated to one retailer.

During the allocation window for opting in or out of an interim supply event, retailers should review their opt in status in CMOS to ensure it accurately indicates the retailer’s decision to be opted in or opted out.
Once the deadline for temporary suspension has passed, no further action is required by retailers until the interim duty supply points are allocated to them, at which point they will need to take all necessary steps to make the supply point(s) tradeable.
If the supply point is metered, retailers will need to make arrangements for the submission of a transfer read to MOSL. This is in accordance with CSD 0102: ‘Registration: Transfers’ and CSD 0202: ‘Meter Read Submission; Process’ in relation to all meters registered at each affected supply point

The exiting retailer will remain responsible for settling any outstanding balance, unless the interim supply process was initiated through an insolvency event. In this case, trading parties should contact the liquidator regarding any outstanding balance.

There is currently no market template available for a wholesaler termination notice. Wholesalers are required to create a termination notice based on the requirements in the Business Terms.

Yes, the exiting retailer will continue to show on all settlement invoices prior to the point of the supply points being transferred to the incoming retailer.

The incoming retailer will be responsible for any costs from the date of cessation of supply or the date of termination for the exiting retailer. The exiting retailer will be responsible for any costs prior to the transfer. The history associated with the supply points will not transfer to the new retailer through the interim supply process.

The date of transfer will be confirmed by Ofwat and MOSL. This timescale will be agreed to ensure a quick and smooth transfer to minimise any customer impact and to provide trading parties enough time to update their opt in status.

If the retailer still has an active Water and Sewerage Supply Licence (WSSL), there is no obligation to terminate the wholesale contract. It is the responsibility of the individual wholesaler(s) to make this decision. If the revocation of supply has taken place for a retailer i.e. Ofwat has revoked the retailer’s licence, any wholesalers with an active wholesale contract should follow the relevant steps laid out in Section 11.2 of the Business Terms. Please note, the wholesaler must provide MOSL and Ofwat with notice of its intention to terminate the wholesale contract at least 10 business days’ in advance i.e. prior to the date of termination specified in the notice.

MOSL has produced a guidance document, which outlines the steps required to view and update your opt in status in CMOS.

The Booster Fund is an additional fund that enables successful projects to apply for an additional sum of money to continue work on their projects after completion. 

Applicants are able to apply for up to 50% of their initial funding allowance and will be eligible to apply for the fund within two years of their contract being signed.

The fund is available to successful round four projects only, and requires a separate application. More information will be available in the round four governance document, with full details available in early 2025.

The application window for the fourth round of the Market Improvement Fund is as follows: 

• December 2024: Application documents reviewed and updated 
• 17th - 28th February 2025: Application window
• March 2025: MOSL review 
• April 2025: Selection Committee shortlisting, shortlist presentations and Strategic Panel ratification
• May 2025: Successful project announcement.

Please note that this timeline is subject to change.

The Market Improvement Fund Expression of Interest Form is an opportunity for potential applicants to let us know whether they are interested in or intending to submit a bid, whether you are looking to seek MOSL sponsorship or require MOSL involvement in your bid (e.g. data sharing), and if you have any questions regarding a potential application or the fund.

Please note that providing information in this form is not considered a formal commitment - all applicants must submit an application as per the application process.

If you would like your project to be sponsored for consideration by MOSL, please contact MIF@mosl.co.uk, providing the following information:

• A high-level summary of your bid, the delivery timeline and the amount being requested
• A rationale for why MOSL (and not a trading party) is your preferred sponsor for your bid
• What level of involvement you expect MOSL to have throughout the project. For example, is there an expectation of MOSL to help deliver the project or will resources from MOSL be required, or are you asking that MOSL sponsor but not have any other involvement?
• How your bid will adhere to the eligibility requirements - enhance market functioning and benefit non-household customers, not considered 'business as usual and does not confer any competitive advantage to any trading party or group of trading parties
• How far you are in the process of submitting your bid.

If all information is provided, we will endeavour to respond to your request within a week with an initial view. However, the time required to make a final decision on MOSL sponsorship will depend on the size and complexity of the bid and level of expected MOSL involvement. We therefore strongly advise you to engage with MOSL as early as possible.

Alternatively, you can submit an Expression of Interest form and we will be in touch.

Please note that if successful, your bid will still need to pass the outlined eligibility checks: an initial eligibility review by MOSL, review by the independent Selection Committee and if successful, final approval by the Strategic Panel.

MOSL is facilitating the Market Improvement Fund on behalf of the Strategic Panel.

As part of this responsiblity, MOSL will assist the independent Selection Committee by ensuring that all applications that are submitted meet the eligibility criteria. However, MOSL will present all applications, those who are both eligable and uneligable, to ensure that the Selection Committee has full visiblity of the applications.

As part of the eligbility criteria, MOSL is allowed to submit or sponsor a bid. These bids will undertake the same eligibility assessment as other bids, and the Selection Committee will be made aware that it is a MOSL bid. 

The Market Improvement Fund (MIF) is a fund that will provide money to projects that benefit the non-household market. It has been designed to compliment Ofwat's Innovation Competitions. We are currently awarding up to a total of £1million to the successful projects. It is owned by the Strategic Panel, but facilitated by MOSL.

In January 2020 an official code change was implemented to allow Market Performance Standard (MPS) and Operational Performance Standard (OPS) charges to be used to create the Market Improvement Fund - this will enable charges to be redirected to better benefit customers and the market. Due to COVID-19 the Market Improvement Fund launch was delayed until 2021. The money that will be distributed to the winning bids will be made up of MPS and OPS charges accumulated throughout the year.

Applicants can bid for a minimum of £10k and a maximum of £200k.

In order to apply to the Market Improvement Fund, the project must: 

• Enhance market functioning and benefit non-household customers
• Could not be considered 'business as usual'
• Does not confer any particular competitive advantage to any trading party or group of trading parties.

Alignment with the Strategic Panel's Roadmap to a Flourishing Market is also strongly encouraged.

Third-party applicants are welcomed, however, the project must be sponsored by a trading party or MOSL.

For a full list of criteria, please see the governance document available on the Market Improvement Fund webpage.

The application window for round four opens from Monday 17th - Friday 28th February 2025. Applications close at 12pm on the final day.

If the winning bids equate to less than the agreed total amount, all monies will be redistributed to trading parties as per the usual process.

All applicants will receive an email to say that their application has been received, as well as a notification of the result of their application. If your application has been shortlisted you will receive an invitation to present your project to the committee. Unsuccessful applications will be given a brief summary as to why their application was rejected.

Following the presentation round, you will receive an email notifying you of your result. Final award of funds will take place once the Funding Agreement has been signed by MOSL and the successful applicant(s).

A list of successful applicants and a brief summary of their project will be published on the MOSL website.

Yes. However, you will need to provide sufficient information to prove that funding has been secured by Ofwat's fund.

The current MPF is a group of mechanisms that govern, monitor and incentivise trading parties to deliver a set of service standards in order to comply with market codes.

Through these standards, the MPF aims to provide confidence to customers that:

• There is an orderly operation of the market
• Trading Parties and MOSL as the market operator are incentivised to comply with their obligations
• The risk of non-compliance and any associated disbenefits are mitigated and managed
• Risks to the central systems are being managed and the performance of the market is being continually improved to ensure its orderly operation.

The current MPF measures provide a view of specific steps in market processes and offer insight on whether tasks are being completed on time. However, there is evidence that the current MPF does not always drive improved outcomes for customers, the market or the environment.

In 2019, the Market Performance Committee (MPC) commissioned Economic Insights to undertake an independent review of the MPF. Following the recommendations, MOSL is embarking on a reform of the MPF.

The overarching aim is to improve upon the current Market Performance Framework whilst ensuring it is aligned to the Strategic Panel’s Outcomes – creating value, great customer service and water efficiency

Feedback from stakeholders (including the Panel, Strategic Panel and our members) indicates strong support for a ‘root and branch’ reform of the MPF. This will consider a range of options, not beholden to the current framework, for effectively incentivising the right outcomes for customers, the market and the environment.

In considering the potential for reform, the Market Performance Committee and its MPF Review working group indicated that a future framework should provide reassurance to market stakeholders that risks to the achievement of key market outcomes are being proactively addressed by:

• Aligning the incentives of trading parties with those of non-household customers to ensure the market delivers the outcomes that benefit current and future customers
• Effectively incentivising and rewarding trading party performance where it leads to a positive customer experience or outcomes
• Ensuring there are appropriate mechanisms to deter, detect and remedy issues when they arise.

The MPF Reform Programme asked market participants to respond to a Call for Inputs (CFI) for MPF reform. The responses informed the development of design principles to be used in assessing the candidate tools to be deployed as part of any future framework.​ These principles incorporate feedback from the MPF Reform Steering Group. They are listed below:

Market Re-assurance is the process by which a tradingparty provides assurance to MOSL that any material change(s) it has made to its business capability does not affect its ability to uphold its market obligations. The Market Re-assurance process is similar to the Market Entry Assurance (MEA) process, except that trading parties only need to complete the stages affected by the material change(s). For example, if a trading party is not changing the way it interfaces with the CMOS or how it sends and receives transactions, it will likely not need to undergo re-assurance testing.

Market Re-assurance will involve completion of the Market Re-assurance Information Return, which sets out how the material change(s) made affect the business capability and the Market Re-assurance Plan, which sets out the timeframe for the rest of the re-assurance process. Depending on the nature of the material change(s), and the MEA route the trading party underwent, market re-assurance can also involve a Self-certification declaration, Business Solution Assessment (BSA), and/or Market Re-assurance Testing.

If you are making a material change(s) to your business capability, which affects the way in which you uphold your obligations, you should consider whether you need to undergo Market Re-assurance. The decision as to whether it's needed, and which stages are required, is decided by the trading party.

The Market Re-assurance process is similar to that of MEA, in that it provides assurance on the business capability to be used in the market. However, when completing re-assurance trading parties do not necessarily need to complete all stages like they would in MEA. There is also no Trading Application to complete and the Market Re-assurance Information Return replaces the Applicant Information Return.

Trading parties completing enhanced Market Re-assurance will likely be required to complete a Business Solution Assessment (BSA). You do not need to complete all the assurance statements, but should complete the approach and risk consideration sections and provide a third party report. You will only need to complete the assurance statements which are affected by the material change(s) for which you are undergoing re-assurance. All other statements can be market as ‘N/A’.

Re-assurance Testing includes Interface and Data Transaction Testing (IDTT) and Market Scenario Testing (MST). All trading parties undergoing Re-assurance Testing need to complete IDTT. However, trading parties will only need to complete the scenarios within MST which are affected by the material change(s) for which they are undergoing Market Re-assurance.

As part of the switching process for metered premises, the incoming retailer must organise a meter read of the supply point for the outgoing retailer, in order to calculate the final bill for the customer and for the incoming retailer to commence billing. This is called a 'transfer read'.

The initial read is the first read that must be submitted for each meter that is added to a new or existing supply point, as part of the meter installation process. This must happen on or before the date on which the supply point becomes effective for new connections or within five to eight business days for existing supply points.

When a read is rejected by CMOS due to validation reasons, but the data submitted is accurate then the retailer/wholesaler can submit a re-read.

All meters that are registered to supply points in the market, or are related to non-market meters, must be read on a regular basis. This read is called a cyclical read. These reads must then be entered into CMOS.

If you have a partners account, then please request your Contract Manager or Authorise user to submit in a proforma with the menu items you need. You will also need to log into the MO portal

For new Trading Parties:

• Contract Manager needs to complete proforma request to onboard your Trading Party on to the MO Portal (fill out sections 1.1, 1.2 and section 1.7). Then request itsupport@mosl.co.uk to create the partners accounts for the members listed in section 1.7 along with MO Portal set up.  
• MOSL will create partner details and assign the menu items to the account.
• MOSL will email login details to the user and confirm the menu items have been added.
• User will login and confirm menu items have been added.

For Existing Trading Parties with new members:

• A Contract Manager, Deputy or Authorised User submits a proforma (fill out section 1.7) to itsupport@mosl.co.uk to create partners accounts along with the MO Portal set up.
• MOSL will create partner details and assign the menu items to the account.
• MOSL will email login details to the user and confirm the menu items have been added.
• User will login and confirm menu items have been added.

The meetings are held on a bi-monthly basis. You can find the latest ORWG dates here.

To obtain meeting invitations, you will need to sign up to the MOSL mailing list and select ‘Operations and Release Working Group (ORWG)’ and/or ‘CMOS and Bilaterals Hub outages, updates and release note’. Visit our 'subscribe' page here.

The meetings are open to all trading parties and their Systems/Data Integrators.

Yes, MOSL is responsible for updating any agenda items, documents and minutes related to the meeting on the website. You can download meeting documentation here.

The ORWG is a group where MOSL and active trading parties meet bi-monthly to discuss technical information and changes related to CMOS functionality and Bilaterals. It includes discussion on:

• Planned Maintenance and Releases
• Update on change proposals, non-code changes and defects in the upcoming releases
• Review of data fixes related to defects
• Data Issues and Improvements
• Technical Bilateral updates.

Not all papers are publicly available due to confidentiality, therefore they will not be publicly available on the website to view.

To view all open Panel vacancies, please visit the Panel Elections page.

To view all vacancies for a committee, please visit the Committee Nominatons page.

If there are any outputs you think are missing from a Panel meeting, please contact us.

Please contact us if you would like to observe a meeting.

First you will require a partners account. If you do not have a partners account, please refer to ‘Partners Account’ section above.

A Contract Manager, Deputy or Authorised user will need to contact itsupport@mosl.co.uk requesting the user to have access to SharePoint detailing the location. A link will be sent via email to invite you on to the SharePoint page.

No, for access to SharePoint or MO Portal, separate requests approved by the Contract Manager, Deputy or Authorised user must be submitted. For CMOS access, you must contact your administrator to set an account up.

Yes, once you have your user details, you can log in and view all protected documents.

To obtain a partners account, you must submit the relevant details to itsupport@mosl.co.uk via our sign-up page. All requests must be authorised by a Contract Manager, Deputy Contract Manager or Authorised user. Please ensure email confirmation has been sent before or along with the account request, so MOSL can create the account.

The RWG has produced good practice guides across a variety of topic areas. Some of the good practice has subsequently been adopted into the market codes.

The calendar on the the RWG page is populated with the forthcoming meetings, as well as the central MOSL calendar. If you can’t find the meeting you are interested in then please email the chair for that meeting.

All topics relevant to the non-household market where we can improve the customer experience are on the table. If you feel that your potential topic is not covered by the existing sub groups then please contact both the main RWG chairs so it can be discussed at the Steering Group.

Most good practice guides include a summary table to indicate which elements of good practice the trading party has adopted.

Adherence to the guidance is voluntary but Ofwat expect trading parties to explain why on an annual basis. Also some guidance will after a specific time period follow an Approved Code of Practice (ACOP) route so therefore will become mandatory.

This is dependant on the topic, but the majority are reviewed by the relevant subgroup every one or two years.

All topics relevant to the NHH market where we can improve the customer experience are on the table. If you feel that your potential topic is not covered by the existing sub groups then please contact both the main RWG chairs so it can be discussed at the Steering Group.

All trading parties are automatically members unless they specifically request not to be involved. Please check with your Contract Manager.

The sub-group chairs can be found under each sub-group heading on the RWG page.

Settlement is the process by which MOSL calculates the charges payable by individual retailers to their related wholesalers, for the supply of water and sewerage services. These are created for each invoice period (monthly). 

Please note, MOSL takes no part in either the invoicing or funds transfer in respect to these charges. These should be dealt with directly by the wholesaler and retailer in accordance with Business Terms. For more information please the Section 4.13 of the Market Terms.

The Central Market Operating System (CMOS) carries out detailed calculations on data maintained by market participants. The calculations of these are detailed in CSD0207: charge calculation, allocation and aggregation and make use of the tariff data maintained by the wholesalers in accordance with CSD0208: submission and validation of wholesaler tariff data. MOSL produces settlement reports, using this data, in accordance with CSD0201: settlement timetable and reporting. For upcoming settlement and report timings, please see the Settlement Timetable.

Following the distribution of the R2, R3, and RF Settlement Reports and the distribution of the R1 Settlement Report, where the pre-payment option has been selected by the retailer based on the P1 report - the wholesaler will calculate the reconciliation balances and invoice the retailer in respect of these balances.

The reconciliation balances are the differences between the amounts already paid by the retailer for the invoice period, and the charges calculated by the updated Settlement Run. As such, reconciliation could result in either a refund or an additional charge being applied to the retailer.

An unplanned settlement run is the recalculation of primary charges for an invoice period outside of the planned schedule of reconciliations. It can be carried out when an incorrect data item has affected the calculation of primary charges reported in a planned settlement run. Unplanned settlement runs will either be carried out by agreement of the impacted trading parties (corrective settlement runs and post RF settlement runs) or following the resolution of a dispute (dispute settlement run). These recalculated values can be used by the affected parties to determine charges due by the retailer to the wholesaler.

Trading parties are able to initiate an Unplanned Settlement Run (USR) request via My MOSL. As the initiator of the application for an unplanned settlement run, you will be required to ensure the below points have been actioned appropriately:

• Ensure that the Supporting Unplanned Settlement Information document has been filled out correctly, including:
  a. The current figure of the incorrect settlement run (or incorrect element);
  b. The projected figure following correction and how this has been determined; and
  c. Demonstrating that the correction will meet the materiality threshold requirement dependent on the type of unplanned settlement run you seek
• Detail sufficient information of each wholesale-retail pairing requiring recalculation
• Determining contributing costs of the unplanned settlement run
• All parties (including indirectly affected organisations) are in agreement of the unplanned settlement run occurring (and any assigned costs), with attachments provided evidencing their approval.

The request will be validated and acknowledged via the portal from which the request was made. Once correctly validated, MOSL will schedule the Unplanned Settlement Run for the next available time.

Once successfully complete, the settlement run will be published and you will be notified of the completion of the Unplanned Settlement Report via the portal where the Unplanned Settlement Run was requested. 

Other trading parties may receive disaggregated reports for meter networks (D3) and/or user exceptions (D4) reports upon the recalculations of a separate wholesale-retail pairing. Please note, this is generated by CMOS but should not affect settlement calculations. If any issues do occur, please contact operations@mosl.co.uk, who are available to provide guidance if there are any queries.

For corrective settlement runs, the materiality thresholds are the larger of :

•  1.0 per cent of the value of the primary charges due to the contracting wholesaler, from the contracting retailer, for the relevant area in that invoice period
• £10,000.00.

For dispute settlement runs, the materiality threshold is the larger of:

• 1.0 per cent of the sum of the aggregate value of the primary charges due to the contracting wholesaler, from the contracting retailer, for the relevant area over all of the relevant invoice periods
• £10,000.00 x the number of runs proposed to be carried out.

For post RF settlement runs, the materiality threshold is the larger of:

• 0.1 per cent of the sum of the aggregate value of the primary charges due to the contracting wholesaler from the contracting retailer for the relevant area for each of the relevant consecutive invoice periods affected
• £3,000.00 x the number of runs to be carried out.

The costs of an unplanned settlement run can be found on the additional services webpage and will be based on the number of wholesale-retail pairings required. However, no charge will apply for pairings where the included retailer is indirectly affected by the actions of other retailers. For example, where a new retailer has provided an inaccurate meter reading within CMOS, but the effects of the meter reading have also affected charges for the previous retailer. The new retailer’s pairing will be chargeable, but the previous retailer’s pairing will be corrected without charge. The costs are to be covered by the impacted trading parties – for voluntary re-runs, costs can be assigned as agreed by the affected parties. Costs accrued through the dispute settlement run will be determined and allocated by the Disputes Committee, the arbiter or the expert as applicable.

The process by which the Credit Support Requirement is calculated is set out in the Wholesale Retail Code (WRC), Part 1, Objectives, Definitions and Principles and the Business Terms. Please note that this requirement is calculated with reference to the value of the P1 Aggregated Settlement Report and as such, may fluctuate between invoice periods.

The Supply Point Identifier (SPID) will stay the same regardless of the tariff applied for settlement, as it relates directly to the premise. If a meter is installed which moves the premise to measured then the wholesaler will need to update the market operator (MOSL) using the T104.W, with all the neccesary data to update this. Settlement charges are calculated on a daily basis and will take into account any changes to tariffs affecting data.

R2, R3, and RF settlement runs are carried out in a consecutive order every two, eight, fourteen and sixteen months after the end of the invoice period. Each run is a complete recalculation of the settlement charges and factors in new and updated data about each supply point, which has been submitted market participants into CMOS.

If you are the data owner, you can correct the data by sending in suitable transactions. Please note, there are some transactions which are currently unavailable. In some cases, it it is possible to use a workaround, as detailed in the workaround log, other times may be necessary to wait until a future CMOS Release to correct the data.

The most likely cause of incorrect settlement is incorrect or missing data. Your first action should be to carefully check the data inputted and your calculation.. If you’re still concerned the settlement is wrong, please fill out the Settlement Clarification Request Form.

P1 runs are carried out before the invoice period, whereas R1 runs are carried out immediately following the invoice period. In accordance with Section 9.2.2 of the Business Terms, a retailer can choose either a pre-payment or a post-payment option with agreement from the wholesaler, in order to pay its primary charges.

As per the Market Terms, an Unplanned Settlement Run can be requested until the end of the Month prior to the next planned Settlement Run. 

Unplanned Settlement Runs for RF periods can be requested inline with the deadlines set out in the Invoicing and Post RF timetable available from the MOSL website. 

Dispute runs should be raised in a timely manner following rectification of the issue.

In the event in which an application is raised or notice has been provided to MOSL prior to publication of the relevant settlement report, the application will not be processed until said reports have been published to the wider market, as per the dates outlined within the MOSL calendar and along the guidelines stipulated within the Code Subsidiary Documents (CSDs).

Unplanned settlement runs must meet the materiality requirements set out in the Market Codes. Where this is not met, trading parties will need to wait until the next planned settlement run.

Participants may have seen a ‘system exception report’ during market testing. The objective of this report is to provide evidence to MOSL of an issue with settlement, primarily due to an internal CMOS defect.

Settlement Runs are done overnight, but will only include transactions up to the end of that business day (6pm).

Market participant’s systems will inevitably not be directly comparable to CMOS, which may result in this variation. For example, participants may have various financial, billing and specialised sub-systems in place, which produce similar, but not directly comparable results. For example, it is possible that a financial system may calculate monthly revenues, but the routines used to calculate consumption will not be the same as those in CMOS. A billing system is likely to produce bills from meter read to meter read, so these would not cover the same period as the CMOS settlement system. However, over a longer period, these effects will balance out.

Yes. P1 Settlement Reports will be provided to all wholesalers and retailers participating in the market.

With regards to disputes, the next Settlement Run will provide corrections to the disputed item(s). A wholesaler can then reconcile against the previous invoice with any over or under charge identified and reconciled. If this can’t be done, or the dispute meets certain conditions as detailed in Market Terms 4.13.4, then an unplanned Settlement Run can be requested.

When a Yearly Volume Estimate (YVE) of zero is supplied, zero settlement charge is calculated.

It is usual for the sums on the reports to differ slightly - this is caused by rounding. For example, in the Aggregated Report all the relevant charges (from multiple supply points) are initially added without rounding. The totals are then rounded to four decimal places. In the Disaggregated Reports the charges in each line are shown rounded to four decimal places. When these rounded numbers are added, there is a minor discrepancy in overall total.

The answer to this varies depending on the organisation. Participants should carry out the appropriate checks in respect to the accuracy of the settlement calculation and of the data supplied, to suit the requirements of their organisation.

The format and content of the Settlement Reports is defined in CSD0201: settlement timetable and reporting. Where defects in the deployed version of these reports have been identified, the reports will be amended to reflect CSD0201.

Whenever an incident record is closed by the Service Desk because it relates to a known defect or it is a new defect, you will be provided with the defect number. Any defect/observations are recorded on the Observation log published on the MOSL website and updated at the end of every week.

If you’re reporting what you believe to be a defect or connection issue, please supply as much of the following information as you can, including:

• The environment the issue occurred, i.e., Production, MPS2 or MPS (it’s mandatory to provide this information)
• Date and time of the issue occurred
• Type and version of the browser used
• A description of the problem
• What you were trying to do
• A summary of why your requirement hasn’t been met
• SPID, Meter, DPID etc. (if related to transactions or notifications)
• Meter Serial Number, Effective Date, Meter Type, Read Type, Supply Status (if related to transactions or notifications)
• Screenshots of error message, spreadsheets, xml files, etc

• When you are having problems connecting to any of the CMOS environments
• The activities you’re carrying out in CMOS (either the B2B interface or Portal) are not producing results as specified in the XSDs or Codes
• If the activity is part of released functionality
• If the issue isn’t part of the published defect list

Any queries related to operational information, interpretation of the codes or guidance will be rejected as the service desk will only review CMOS issues related to defects. For these types of queries, trading parties should contact operations@mosl.co.uk.

When an email is sent, the Service Desk agent who receives it will validate that your email address is registered as an authorised contact and will add your issue/email content to a ticket. A response will be sent with a ticket reference number.

If you are not an authorised user, you will receive a reply advising you of this. 

The Service Desk agent will validate your identity by using your email address, telephone number and work address to check. They will then ask a few questions with regards to your call to make sure that the Service Desk is the right option for your issue (you will be advised who to contact if not). They will then take details of the problem and issue you with a reference number. 

Only authorised individuals can contact the Service Desk. If you’re unsure who the authorised users are for your organisation, please can email itsupport@mosl.co.uk, to obtain a list of authorised users. The request must be approved by a Contract Manager, Deputy Contract Manager or Authorised user.

The MOSL Service Desk can be contacted by telephone or email 24/7. Emails received out of hours will be processed on the next working day. 

• E-mail – MOSLservicedesk.uk@cgi.com
• Telephone – 0333 207 6589

In autumn 2023, the Panel published a updated set of priority market outcomes and areas of work for the market which focus on the areas that have the greatest impact on customers. The Panel sought feedback these at our 2023 Open Forum and on the back of this have continued to focus on creating value for stakeholders, excellent customer service and water efficiency. The Panel's Roadmap to a Flourishing Market published in September 2024 will largely replace the Panel’s Priorities document with the Panel’s principal workstreams and priorities being derived from the activities set out in the roadmap.

Incoming and outgoing retailers must cancel a switch within the cancellation window. This window is five business days from the date of the transfer request being submitted.

An incoming retailer can cancel the process of customer switching during this window if they realise that the wrong supply point has been selected and is in the process of being transferred, or if they hold an invalid contract.

The outgoing retailer may also cancel the switch if the customer has an outstanding debt, the contract remains binding, or if the outgoing retailer holds a self-supply licence.

Customers must sign a contract with the incoming retailer they wish to switch to. The outgoing retailer will be notified of the switch after the transfer registration has been submitted and will have an opportunity to confirm the switch with the customer. A transfer read will need to be taken for any meters on the premises, to calculate the final bill from the outgoing retailer.