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Unmetered Supplies (UMS)

The information on this page will be of interest to Data Collectors, Distributors, Manufacturers, Meter Administrators, Suppliers, UMSOs and customers with unmetered supplies.

Unmetered Supplies (UMS) exist in the half hourly and non-half hourly Supplier Volume Allocation (SVA) markets. An UMS can only be provided in accordance with PDF BSCP520 - 'Unmetered Supplies Registered in SMRS' (256Kb) . The Unmetered Supplies Operator (UMSO) provides the UMS service on behalf of a distributor.

Any queries regarding Unmetered Supplies, charge codes or general queries should be directed to the Unmetered Supplies User Group (UMSUG) Technical Secretary.

Picture of Abi Akala

Abi Akala

Business Operations Consultant

Telephone: 020 7380 4347

Email: Abi.Akala@elexon.co.uk

Operational Information

The Operational Information document was created in June 2005 from the former appendices to BSCP520. It contains technical information concerning UMS equipment and consumption ratings (via charge codes), including the procedure for allocating charge codes to new equipment, and annual hours to be allocated to each Switch Regime for the purpose of calculating EACs. The document will be of use primarily to UMS Suppliers, UMSOs, equipment manufacturers and Customers.

Charge codes are 13 digit numbers (formerly 7 digits) assigned to items of apparatus that UMS customers wish to add to their inventories. From 26 June 2008 all charge codes can only be issued in the new 13 digit format as set out in the PDF ‘New Charging Code Structure for Unmetered Supplies’ Guidance Note (88Kb) . Charge codes are used within the UMSO systems to calculate volumes of electricity consumed. If a customer is using a piece of equipment, it must go on the inventory with a provisional (P) or confirmed (C) charge code. The application procedure for a charge code for a new piece of equipment is contained within the Operational Information document in the table below.

Switch Regimes detail the on/off times of apparatus. The application procedure for a switch regime is the same as that for charge codes.

Notify me when a document is added/updated to this table Notify me when a document is added/updated to this table
TitleVersion Documents to add to basket Notifying of updated documents
PDFUnmetered Supplies Operational Information (235Kb)7.0
ExcelUnmetered Supplies Operational Charge Codes - xls (513Kb)2.3
ExcelUnmetered Supplies Operational Charge Codes - csv (513Kb)2.3
ExcelUnmetered Supplies Operational Switch Regimes - xls (65Kb)1.9
ExcelUnmetered Supplies Operational Switch Regimes - csv (27Kb)1.9
ExcelNon Standard Conversion Charge Codes - xls (44Kb)1.0

The UMSUG Chair has the authority to agree interim provisional charge codes until these are formally approved by the Supplier Volume Allocation Group (SVG) and included within the Operational Information charge code Spreadsheet. The files above identify provisional Charging Codes distinct from those that are already approved by the SVG. These codes should be used until formal notification is issued by the BSCCo.

Please note that the charge codes contained within the Unmetered Supplies Operational Information document are no longer contained within a Code Subsidiary Document. No BSCP520 appended documentation will be produced.

If the charge code you require is not listed in the document above please make an application in accordance with the process detailed testing procedure contained in the Unmetered Supplies Operational Information document, available from the table above.

Refer to the table above to download the Unmetered Supplies Operational Information document in PDF format or the charge codes and Switching Regimes in XLS format.

Equivalent Meters

An Equivalent Meter is the hardware and software that is used to calculate Half Hourly electricity consumption values associated with Unmetered Apparatus. The specification for an Equivalent Meter is contained within PDF BSCP520 ‘Unmetered Supplies Registered in SMRS (256Kb) .

Equivalent Meters are of two types:

  • Passive Meters – which allocate the Unmetered consumption across the half hourly periods by a mathematical relationship of annual burning hours to the daily time of sunrise and sunset; and
  • Dynamic Meters – which allocate the Unmetered Consumption across the Half Hourly periods by reference to the operation of a number of photoelectric cells (PECU Arrays) or by making use of actual switching times reported by a Central Management System (CMS). Where the switching times are reported by CMS the Equivalent Meter can be defined to be two distinct parts: the CMS (i.e. the system that is used to report switching times) and the Meter Administrator (MA) System (i.e. the system that is used to calculate the consumption). The definition of the file that is used to transfer data from the CMS System to the MA System is defined in BSCP520.

CMS Capable Equivalent Meters

Central Management Systems form part of the Meter Administrator’s Equivalent Meter. Where the switching times are reported by a CMS, the Equivalent Meter can be defined as two distinct parts: the CMS (i.e. the system that reports switching times and/or power levels) and the Meter Administrator (MA) System (i.e. the system used to calculate the consumption). An Equivalent Meter that can facilitate CMS is called a CMS Capable Equivalent Meter.

We have produced some guidance for CMS manufacturers and CMS operators (customers) which you can download from the table below.

Notify me when a document is added/updated to this table Notify me when a document is added/updated to this table
TitleIssue Date Documents to add to basket Notifying of updated documents
PDFCentral Management Systems Guidance Note - Manufacturers (296Kb)05/03/2009
PDFCentral Management Systems Fact Sheet - Customers/Operators (235Kb)05/03/2009

An interested party must apply to ELEXON to gain approval for an Equivalent Meter, either for a new CMS or a new CMS Capable Equivalent Meter.

Please contact Kevin Spencer on 020 7380 4115 to discuss your application.

We will provide applicants with a test specification and will agree a test schedule and give expected timescales for the approval process. The testing will be carried out by an ELEXON appointed Equivalent Meter Test Agent (currently ELEXON). This will be agreed between ELEXON and the applicant.

The test specification can be downloaded from the table below.

Notify me when a document is added/updated to this table Notify me when a document is added/updated to this table
TitleIssue Date Documents to add to basket Notifying of updated documents
PDFCentral Management System Equivalent Meter Test Specification (285Kb)18/08/2008

Once testing of the system(s) is complete, results will be presented to the Unmetered Supply User Group (UMSUG) for recommendation for approval. The application will then be presented to the Supplier Volume Allocation Group (SVG) for approval.

For a new CMS Capable Equivalent Meter, ELEXON will be required to test the complete system (i.e. MA system and CMS). However, in the case where the CMS and / or the MA system is tested and approved with another CMS / MA system, this will be taken into account in the testing (which may lead to a reduction in testing / no testing required by ELEXON). All new Equivalent Meters must be presented to the SVG for approval, even in the case where the CMS and MA System that they comprise have been approved with other CMS / MA Systems.

Listed below are the currently approved Equivalent Meters. For ease of reference, they are divided into approved Equivalent Meters that include CMS (CMS Capable) and those that do not include CMS (Non-CMS Capable):

Meter Administrators Equivalent Meter CMS Capable
E.ON Energy Ltd FLARE -
Npower Northern Ltd LAMP -
Power Data Associates Ltd Lailoken (CMS Capable) Yes
Siemens Metering Services LAMP -
Southern Electric Power Distribution Plc LAMP -
SP Dataserve Ltd LAMP -
United Utilities Networks Limited LAMP -
Western Power Distribution (South Wales) Plc Lailoken -
Western Power Distribution (South West) Plc Lailoken -
Last Updated: 7 January 2009


Approved CMS Version
WiMAC 2.0
Last Updated: 7 January 2009

Unmetered Supplies User Group (UMSUG)

The UMSUG are the expert forum that make proposals to the Balancing and Settlement Code Company (BSCCo) in respect of revisions to the relevant UMS's Code Subsidiary Documents (BSCP520 and PSL100) and the resolution of problems relating to UMS.

The UMSUG meet on a quarterly basis, minutes from the meetings are published in the table below in PDF format. The terms of reference for the UMSUG, meeting dates for 2008 and 2009 and the contact details for the UMSUG members are also available from the table below.

Notify me when a document is added/updated to this table Notify me when a document is added/updated to this table
Title Documents to add to basket Notifying of updated documents
PDFTerms of Reference (1Mb)
PDFMeeting Dates for 2009 (18Kb)
PDFDraft Minutes of Meeting - 13/05/2009 (68Kb)
PDFMinutes of Meeting - 11/02/2009 (99Kb)
PDFUMSUG Members (49Kb)
ZipMinutes of Meetings 2008 (506Kb)

To download the minutes from previous meetings go to the UMSUG Minutes 2001- 2007 page.

If you have any trouble viewing the data displayed on this page, please contact the BSC Service Desk on 0870 010 6950 or by emailing bscservicedesk@logica.com. All queries regarding Unmetered Supplies may be directed to the UMSUG Technical Secretary.

Registered office: 4th Floor 350 Euston Road London NW1 3AW   Reg Co No: 3782949 Registered in England and Wales