Unmetered Supplies


An Unmetered Supply is any electronic equipment that draws a current and is connected to the Distribution Network without a meter recording its energy consumption. Unmetered Supplies (UMS) exist in the half hourly and non half hourly Supplier Volume Allocation (SVA) markets.

How it relates to you

Paragraph (1) of Schedule 7 to the Electricity Act 1989 and Paragraph (1A) of Schedule 7, as inserted by the Utilities Act 2000 outline the regulation around the circumstances in which a supply of electricity may be unmetered.

The UMS process is governed by BSCP520 – Unmetered Supplies Registered in SMRS.

The Unmetered Supplies Operator (UMSO) provides the UMS service on behalf of a distributor.

The processes within BSCP520 must be carried out effectively. Charge codes and switch regimes will be delivered to customers such as product manufacturers, county, borough councils that have an Unmetered Supply inventory.

Elexon also coordinate the Central Management Systems (CMS) process, which is the next step in remote dynamic street lighting control.

Managing Unmetered Energy Street Lighting Inventories document has been endorsed by the ADEPT Lighting Group, Elexon, the Energy Networks Association, the Institution of Lighting Professionals, the UK Lighting Board and the Local Government Technical Advisers Group as representing good practice in establishing, maintaining and auditing inventories for unmetered street lighting supplies.

Modifications impacting customers

P434 ‘Half Hourly Settlement for UMS Metering Systems’ will require a period of mandatory Change of Measurement Class (CoMC) activity for all Non-Half Hourly (NHH) Unmetered Supplies (UMS) Metering Systems running from October 2023 to October 2024.

It will also require all new UMS connections to be settled Half Hourly (HH) from October 2023.

Unmetered Supplies Contacts

This form provides contact details for the companies that fulfil Unmetered Supplies roles and functions.

Groups and committees

The Unmetered Supplies User Group (UMSUG) is an expert group that provides advice on specific UMS related matters.


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