By March 2026, all CT Metering Connections must be upgraded to more efficient measuring CTs. This change is part of new regulations introduced by the Balancing and Settlement Code (BSC), managed by Elexon, which ensures the stability and efficiency of the electricity market.
The updates to CT metering connections fall under P432, a modification for Half Hourly Settlement (HHS) of Current Transformer (CT) Advanced Metering Systems.
Why Does the March 2026 Deadline Matter?
By this date, all CT Metering Connections must transition from Non Half Hourly (NHH) settlement to Half Hourly (HH) settlement. This transition must be carried out using the Change of Measurement Class (CoMC) process.
Who is Responsible for Upgrading CT Metering Connections?
The CoMC process is managed by key industry players, including:
Suppliers – Companies that provide electricity, like British Gas and EDF Energy.
Meter Operator Agents (MOAs) – Responsible for installing, maintaining, and ensuring meter accuracy. Example: Siemens.
Data Collectors – Process energy usage data for billing. Example: IMServ.
Some suppliers also act as MOAs and Data Collectors, streamlining the process.
What is the Change of Measurement Class (CoMC) Process?
As always there are two sides to these process, the administrative and the actual works. Regarding the changes to the equipment, these are mainly the meter itself, the CT Metering Panel and the Current Transformers (CTs) inside. Upgrades may simply involve changing over CTs to 0.5s high accuracy ones or opting to get a new CT Metering Panel altogether depending on what the supplier (or property owner) sees fit.
The CoMC process, outlined in P432 of the BSC, involves these key steps:
1. Initiation
A supplier identifies a metering system that needs to transition from NHH to HH settlement—either due to regulations or to improve accuracy.
2. Notification
The supplier informs relevant agents (MOAs and Data Collectors) about the change, using specific data flows:
D0155 – Notifies new agents.
D0151 – De-appoints old agents.
3. Metering Equipment Check
If the existing meter can support HH data collection, no replacement is needed.
If not, new compliant metering equipment must be installed.
4. Data Collection Setup
The Half Hourly Data Collector (HHDC) configures the system to collect data every 30 minutes, either remotely or through a site visit.
5. Proving Tests
Tests ensure the meter accurately records and transmits half hourly data. These tests are often done remotely.
6. Settlement System Update
The Supplier Meter Registration System (SMRS) is updated to reflect the new measurement class, ensuring proper processing.
7. Ongoing Monitoring
After the switch, metering data is continuously monitored to ensure accuracy in settlements.
This process helps create a more efficient and transparent energy market.
Are there any penalties for noncompliance with CoMC?
If suppliers and other parties don’t follow the Change of Measurement Class (CoMC) process, they can face several penalties. These include financial fines, enforcement actions like compliance notices and investigations, reputational damage, and operational disruptions.
It is important for suppliers and other stakeholders to stay informed about the requirements and timelines for the CoMC process to avoid these penalties and ensure a smooth transition before March 2026.
Background: How Did This Change Come About?
The P432 modification introduced the following key changes:
Alignment with Standard License Conditions (SLC) – The BSC definition of an Advanced Meter now aligns with regulatory standards.
Mandatory Half Hourly Settlement – All CT Advanced Meters currently settled on NHH must transition to HH by March 2026.
New Connections Rule – From April 2024, any new CT Advanced Meter connections must use Half Hourly Settlement (See our post on high accuracy CTs 0.5s)
Support for Market Wide Half Hourly Settlement (MHHS) – This transition promotes better energy management and efficiency.
Consumer Protection – Measures are in place to prevent excessive capacity charges during the transition.
These updates improve energy settlement accuracy, encourage efficient energy use, and support a more competitive market.
How Ritherdon Can Support Your Transition
Ritherdon is a trusted manufacturer of CT Metering Panels and supplier of CTs, offering high quality solutions to support your transition to Half Hourly Settlement.
Our range of CT Metering Panels includes:
Remote Metering Panels – COP 2 HV, COP 3 HV, COP 5 HV & COP 5 LV Metering Panels.
All these CT metering panels ensure compliance with the new regulations while providing reliable and efficient metering solutions.
Ritherdon can support all parties involved, from suppliers to electrical contractors and electricians to landlords and BNOs, as well as Independent Connection Providers (ICPs), who may decide to simply upgrade CTs to a new metering class 0.5s or get new CT metering panels altogether, to meet new conditions.
All these items are available to shop online, explore the range and ensure compliance before the deadline.
Need More Information?
Find the full BSC Guidance Notes on CoMC and CoPC and P432:
Act Now! Ensure compliance before March 2026 to avoid penalties and benefit from improved energy efficiency.
