Changes to Supply Number Format for MHHS (Alternative)
Summary
The Electricity Supply License requires Suppliers to provide the Supply Number to each Consumer on every bill, or at least once per year where no bill has been sent. The Supply Number format is prescribed by the REC and is detailed in the Energy Market Data Specification. The MHHS design is changing the data associated with each individual metering point, including those data items currently displayed within the Supply Number top line. This is an Alternative Change Proposal to R0083, which proposes to replace the format of the top line in the Supply Number Format. This Change Proposal proposes to remove the top line completely from the S Number format. Both solutions are being progressed together to allow for a clear assessment of the benefits and drawbacks and impacts to consumers.
Latest update and next planned activity
Date of latest update
Latest Update
17/11/2023 - The Authority has rejected R0083A, but has approved R0083 for implementation on MHHS M8 *This Change Proposal is a consequential change from the Market-wide Half Hourly Settlement programme
Impacts Overview
Impacted Consumers
Electricity
Impacted REC Parties and Market Participants
Energy Supplier
Distribution Network Operator
Impacted REC Services
Electricity Enquiry Service (EES)
Priority and rationale
High
Priority last updated on 29 May 2026
Solution development
Problem Statement
The Market-wide Half Hourly Settlement design is impacting the Data Items that are used in the top line of the Supply Number, which Energy Suppliers are obliged to provide to Consumers at least once a year under their Licence. A revised definition of the Supply Number format is required so that Electricity Suppliers have a clear understanding of the approach to populating the Supply Number for metering points that have migrated to the new MHHS arrangements.
Proposed solution summary
- As an electricity Consumer I want to be able to provide my prospective Energy Supplier with the necessary information for them to provide a suitable tariff. As a Non-Domestic Consumer, I want to have the necessary information that will allow me to access tariff information, specific to my business, to help me manage my energy. As an electricity Consumer, I want to have access to the data that will help me appoint my own Metering Equipment Manager (MEM) where permitted.
- As a Supplier, I want to know how to populate and format the Supply Number, so that I can meet my obligations to include it in Consumer bills or statements. As a Third Party Intermediary (TPI), I want Consumers to be able to provide me with the right information to provide appropriate quotes.
- As an independent Distribution Network Operator, I want to be able to identify and use the DUoS Tariff Id so that I can provide transparency on charging that is being applied to my customers. As the Electricity Enquiry Service (EES) Provider, I want to know how to populate the Supply Number so that I can make it available on the EES
No documents available.
There is currently no Change Plan.
Original submission
Change details
Jon Hawkins - -
6 Dec 2022
Change details
Changes to Supply Number Format for MHHS (Alternative)
The Electricity Supply License requires Suppliers (under SLC 20.4, SLC 31G.8 and SLC 31H.4) to provide the Supply Number to each Consumer on every bill, or at least once per year where no bill has been sent. The Supply Number format is prescribed by the REC and is detailed in the Energy Market Data Specification.
The current format of the Supply Number includes:
• a top line, consisting of the Profile Class Id, Meter Timeswitch Code (MTC) and Line Loss Factor Class (LLFC) Id; and
• a bottom line consisting of the Distributor Id, Unique reference number and Check digit that make up the MPAN.
The Market-wide Half Hourly Settlement (MHHS) design is removing the use of Profile Classes (with the exception of legacy non-smart meters), removing MTCs and separating the LLFC Id to create a new Line Loss Factor (LLF) Id and DUoS Tariff Id.
This will impact the format of the Supply Number, which would require Electricity Suppliers to change the number provided to Consumers on their bills / statements.
The current format of the Supply Number includes:
• a top line, consisting of the Profile Class Id, Meter Timeswitch Code (MTC) and Line Loss Factor Class (LLFC) Id; and
• a bottom line consisting of the Distributor Id, Unique reference number and Check digit that make up the MPAN.
The Market-wide Half Hourly Settlement (MHHS) design is removing the use of Profile Classes (with the exception of legacy non-smart meters), removing MTCs and separating the LLFC Id to create a new Line Loss Factor (LLF) Id and DUoS Tariff Id.
This will impact the format of the Supply Number, which would require Electricity Suppliers to change the number provided to Consumers on their bills / statements.
The MHHS design is changing the data associated with each individual metering point, including those data items currently displayed within the Supply Number top line. To support Electricity Supplier implementation of the MHHS arrangements, a clearly defined solution is required setting out a revised approach to populating the Supply Number on Consumer’s bills and statements.
Without this change, Electricity Suppliers will need to make individual assumptions on how to populate the Supply Number fields where data is no longer available, leading to inconsistencies and a lack of clarity for Consumers.
Without this change, Electricity Suppliers will need to make individual assumptions on how to populate the Supply Number fields where data is no longer available, leading to inconsistencies and a lack of clarity for Consumers.
The outcome of this REC CP should include a revised definition of the Supply Number format, either replacing or removing the redundant data items for migrated metering points.
This is an Alternative Change Proposal to R0083, which proposes to replace the format of the top line in the Supply Number Format. This Change Proposal proposes to remove the top line completely from the S Number format. Both solutions are being progressed together to allow for a clear assessment of the benefits and drawbacks and impacts to consumers.
A clear implementation approach is required, setting out how and when the changes will be applied e.g. whether the existing and new formats will continue in parallel for the MHHS migration period.
This is an Alternative Change Proposal to R0083, which proposes to replace the format of the top line in the Supply Number Format. This Change Proposal proposes to remove the top line completely from the S Number format. Both solutions are being progressed together to allow for a clear assessment of the benefits and drawbacks and impacts to consumers.
A clear implementation approach is required, setting out how and when the changes will be applied e.g. whether the existing and new formats will continue in parallel for the MHHS migration period.
RECCo and the Code Manager have been considering this issue as part of its MHHS programme of work. A consultation was issued in October 2022. 12 responses were received from Electricity Suppliers, DNOs, iDNOs and Meter Administrators. A summary of responses to the consultation have been included for information .
The consultation responses highlighted that there was no consensus from industry participants on whether a top line should be retained in a different format, or the top line should be removed entirely.
The consultation responses highlighted that there was no consensus from industry participants on whether a top line should be retained in a different format, or the top line should be removed entirely.
Impacts
Electricity
Switching experience
The information currently displayed in the top line of the Supply Number, in particular the LLFC Id is used to support switch processes. It has been suggested that domestic consumers are unlikely to use this information (although they may be asked to provide it to a gaining supplier); whereas for larger, non domestic consumers the LLFC Id provides transparency for Consumers of their DUoS charges and the top line data supports Consumers who chose to appoint their own agents.
No details provided
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No details provided
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No details provided
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No details provided
The S Number Format is defined in the Data Specification but is not included in any of the options above.
No details provided
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No details provided
The Supply Number is displayed on the EES. Therefore the new format will need to be applied. The consequential changes to the EES are being managed through the MHHS programme, therefore the Code Manager does not need to include the required changes to the EES in this solution. However, there will need to be close engagement with the RECCo MHHS team to ensure both solutions are aligned.
Energy Suppliers, Distribution Network Operators
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No details provided
Whilst the Supply License doesn’t define the actual format of the Supply Number, it does set out the overall requirement to include the number on customer bills. The Code Manager should ensure Ofgem is engaged in discussions throughout.
Yes
No details provided
Priority & timing
No
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This change is required before metering points start migration to the new MHHS arrangements (it is assumed that changes will not be required to support MHHS testing activities).
The MHHS programme plan is currently being revised, with the new plan to be issued for consultation in December 2022 . It is therefore not possible to specify a date by which this change is required.
Responses from the earlier Supply Number consultation have indicated that suppliers will require a 12+ month implementation lead time and this will be taken into account in the change proposal plan.
The MHHS programme plan is currently being revised, with the new plan to be issued for consultation in December 2022 . It is therefore not possible to specify a date by which this change is required.
Responses from the earlier Supply Number consultation have indicated that suppliers will require a 12+ month implementation lead time and this will be taken into account in the change proposal plan.
Electricity Suppliers require a clear understanding of the approach to populating the Supply Number for metering points that have migrated to the new MHHS arrangements.
No details provided
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Activity
Proposed solution summary changed to As an electricity Consumer I want to be able to provide my prospective Energy Supplier with the necessary information for them to provide a suitable tariff. As a Non-Domestic Consumer, I want to have the necessar…
Proposed solution summary changed to As an electricity Consumer I want to be able to provide my prospective Energy Supplier with the necessary information for them to provide a suitable tariff. As a Non-Domestic Consumer, I want to have the necessary information that will allow me to access tariff information, specific to my business, to help me manage my energy. As an electricity Consumer, I want to have access to the data that will help me appoint my own Metering Equipment Manager (MEM) where permitted.As a Supplier, I want to know how to populate and format the Supply Number, so that I can meet my obligations to include it in Consumer bills or statements. As a Third Party Intermediary (TPI), I want Consumers to be able to provide me with the right information to provide appropriate quotes.As an independent Distribution Network Operator, I want to be able to identify and use the DUoS Tariff Id so that I can provide transparency on charging that is being applied to my customers. As the Electricity Enquiry Service (EES) Provider, I want to know how to populate the Supply Number so that I can make it available on the EES.
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