Trading parties can raise a dispute if they believe another party in the market is operating incorrectly in relation to; incorrect data items, inaccuracy of settlement reports, non-adherence to the Market Arrangements Code (MAC) obligations and/or non-adherence to other areas of the code.

You can find out more about the different types of disputes below, along with a list of all active disputes.

Trading Disputes

Trading Disputes occur when two trading parties disagree on whether a data item has been accurately maintained, which has had an effect on Primary Charges. Under the Market Arrangements Code (MAC), parties have an obligation to ensure that data is maintained accurately. In the event of inaccuracy, raising a Trading Dispute effectively escalates the dispute to ensure rectification. Prior to raising a Trading Dispute, however, a trading party must make all reasonable steps to resolve the discrepancy with the parties involved.

For more information, please visit the Trading Disputes page.

Market Operator (MO) Disputes

The Market Operator (MO) Dispute resolution process aims to rectify any errors considered to be the cause of inaccurate results occurring within the Settlement Report. An error can be raised by the contracting wholesaler or retailer, but must not be due to errors in or omissions of any data items, as this would constitute a Trading Dispute.

For more information, please visit the MO Disputes page.

MAC and Non-Trading Disputes

MAC Dispute resolution is designed to resolve any issue, in which a trading party believes an organisation, either MOSL or another trading party, has failed to comply in accordance with their obligations, as stipulated in the market codes. A Non-Trading Dispute follows the same procedure as that contained within the MAC Dispute. The dispute will have the same process, but will differ in terms of the scope.

For more information, please visit the MAC and Non-Trading Disputes page.

Disputes List

Please find the list of all open disputes below, and disputes closed in the last 12 Months.

Dispute type Publication date Title Description
Unified 26/03/2021 Closed:13/09/21 DIS0032 Updated 13/09/21: Closed. From the original volume there are a handful of SPIDs awaiting resolution which can be resolved by ongoing work between Thames Water and Castle Water. Original Dispute wording: Castle Water Limited (Castle) asserts that Thames Water Limited (Thames) have not used Visual reads when submitting Final reads in the case of 417 SPIDs . This is contrary to Section 3.3.3 of CSD0202 Meter Read Submission: Process - “The only permitted Meter Read Method for a Final Read is “Visual”.
Unified 20/11/2020 DIS0021 Thames Water state that Castle Water are incorrectly withholding settlement charges relating to SPIDs where Castle Water state that Thames Water as a Wholesaler have a responsibility to provide remote reading systems.
Non Trading 06/05/2020 COD00060 Marston’s PLC has raised a dispute with Severn Trent Water in relation to Wholesale Retail Code: Business Terms – Schedule 3: Alternative Eligible Credit Support. The parties are yet to agree on a resolution and the dispute remains open.
MAC 19/11/2018 COD00054 Thames Water provided Castle Water with a list of supply points, where an issue has been identified concerning to defective meter pit covers. As a result, meter reads were unable to be taken.
MAC 19/11/2018 COD00053 A list of supply points held by Thames Water have been identified by Castle Water as having meters located in an unsafe location and subsequently meter reads were unable to be taken.
MAC 19/11/2018 COD00051 A list of supply points held by Thames Water have been identified by Castle Water as having an issue related to damaged meters. As such, meter reads are unable to be input.
MAC 19/11/2018 COD00049 Castle Water has identified a number of supply points held by Thames Water with meters associated with defective reading systems. As such, meter reads are unable to be input.
Unified 20/11/2020 DIS0020 Thames Water state that Castle Water are incorrectly withholding settlement charges relating to SPIDS which Castle Water have stated are outside the SLA for completing the bilateral requests. Thames Water escalated 2159 out of the 3257 SPIDs to the DC. The DC found in Thames Water’s favour and required Castle Water to pay the outstanding wholesale charges. Castle Water has referred this decision to arbitration. Thames Water and Castle Water continue to work to agree resolution for the remaining Disputed SPIDs not escalated to the DC.
Unified 06/05/2020 Closed: 02/09/2021 DIS0031 (COD00061) The Disputes Committee (DC) held a closed session to hear DIS0031, which had been brought by Elis UK Limited (ELIS) and in which the responding party was South West Water Ltd (SWW). In this Dispute, ELIS asserted that SWW had not complied with Schedule 3 of the Business Terms (Alternative Eligible Credit Support) in that they failed in their consideration to develop and introduce a credit offering that is in alignment with what Ofwat indicated to be notable examples of best practice. The DC found that SWW had not breached Schedule 3 of the Business Terms on the basis that the code contains no obligation to reach agreement. The DC noted that SWW had recently documented an agreement for Alternative Eligible Credit Support with ELIS, which was signed by both parties on 23rd June 2021 and posted on the MOSL website.
Unified 06/09/2021 Closed 28/09/21 DIS0034 Update 28/09/21. Both parties have confirmed this as closed. Meter was running backwards due to a cross connection within the customer’s premises which is causing backflow through meter. Original wording from 6/9/21: Castle Water Limited (Castle) have raised a non-trading dispute against Thames Water Limited (Thames) alleging that Thames is in breach of 4.2.1 of the Wholesale Contract Schedule 1, Part 2: Business Terms in that, as Contracting Wholesaler, it their responsibility to “provide, maintain, repair and, either routinely or where faulty, replace the meter(s)”, which in the case of the listed meters, they have failed to do.
Unified 06/10/2021 DIS0035 Castle Water Limited (Castle) have raised a dispute DIS0035 regarding a SPID which they assert entered the market with two actual reads from the wholesaler (Thames Water Limited (Thames) that have since been found to be estimates. Castle asserts that the pre-loaded reads were under-estimating the actual consumption; actual reads since market opening, compared to the pre-market opening reads suggest a rise in consumption that is not in line with the comparison of year on year actual reads since market opening. The primary charge has therefore been significantly inflated. No evidence exists of any leakage or explanation for the increased consumption.


Disputes Committee

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