Traditionally, Half Hourly meters were only mandatory for the largest supplies and, as the name suggests, are installed to measure electricity data every 30 minutes. Smaller supplies including domestic are captured under the Non Half Hourly umbrella. 30 minute data is not used for your bill with monthly reads used instead. These are translated into more granular data for Settlement.

Half Hourly and Non Half Hourly are both ‘Measurement Classes’.


What is a Measurement Class?

Measurement Classes group supplies by their level of demand and impact the type of metering system that you require.

The table below shows the different Measurement Classes that exist.


Measurement Class A
Non Half Hourly Metered

Measurement Class B
Non Half Hourly Unmetered

Measurement Class C
HH metered in 100kW Premises

Measurement Class D
Half Hourly Unmetered

Measurement Class E
Half Hourly Metering Equipment at below 100kW Premises with current transformer

Measurement Class F
Half Hourly Metering Equipment at below 100kW Premises with current transformer or whole current, and at Domestic Premises

Measurement Class G
Half Hourly Metering Equipment at below 100kW Premises with whole current and not at Domestic Premises


What class is my meter?

You can tell if you have a Half Hourly or Non Half Hourly meter by looking at the first two digits of your S number also called your ‘full MPAN’. An S number is the full 23 digit unique identifier for your metering point and can be found on your energy bill. The first two digits denote your Profile Class, which will tell you your Measurement Class.

S-number (2)

Profile classes categorise supplies into 8 different types based on how and when they consume energy. These classes allow the ‘profiling’ of sporadic meter reads into a shape for billing purposes – this is called a Load Profile.


Profile Class 1
Domestic Unrestricted Customers

Profile Class 2
Domestic Economy 7 Customers

Profile Class 3
Non-Domestic Unrestricted Customers

Profile Class 4
Non-Domestic Economy 7 Customers

Profile Class 5
Non-Domestic Maximum Demand (MD) Customers with a Peak Load Factor (LF) of less than 20%

Profile Class 6
Non-Domestic Maximum Demand Customers with a Peak Load Factor between 20% and 30%

Profile Class 7
Non-Domestic Maximum Demand Customers with a Peak Load Factor between 30% and 40%

Profile Class 8
Non-Domestic Maximum Demand Customers with a Peak Load Factor over 40%


As Half Hourly meters already show a distinct shape of consumption by collecting data in 30 minute chunks, they have a profile class of 00.

Before April 2017, a Half Hourly meter was only required if you had a demand of over 100kW. Now, all Non-Domestic Maximum Demand (Profile Classes 5-8) customers have been moved into the Half Hourly market following P272. New Measurement Classes (E,F and G) were created to accommodate this change.

By increasing the number of supplies settled half hourly, the UK has moved towards a smarter electricity network.