Half-hourly meters explained

What a half-hourly meter is

A half-hourly (HH) meter records how much electricity your site uses in each half hour of the day, rather than one running total. The readings are collected remotely, so nobody needs to visit the site to read the meter, and your supplier bills you from actual half-hourly data instead of estimates.

In industry terms, half-hourly is as much about settlement as about the meter. Settlement is the process, run under the Balancing and Settlement Code administered by Elexon, that works out how much electricity each supplier's customers used in each half hour so that suppliers pay for the right amount. A half-hourly settled site has its actual half-hourly readings used in that process. Smaller sites have historically been settled using standard load profiles instead, which estimate when in the day the energy was used.

You can tell a half-hourly settled supply from the top line of the full MPAN: Elexon's MPAN guidance says the half-hourly profile class is shown as 00. Non-half-hourly supplies show a profile class from 01 to 08. Our MPAN number guide explains the rest of the number.

Which sites have half-hourly meters

Half-hourly metering is the norm for larger business electricity supplies. Two rules explain why.

• Advanced metering for larger sites. Ofgem's smart metering licence guide says that since 6 April 2014 suppliers must supply larger non-domestic sites, electricity sites in profile classes 5 to 8, through an advanced meter that records use for multiple time periods and can be read remotely, unless they cannot install one despite all reasonable steps.
• Mandatory half-hourly settlement (P272). Elexon's code change P272 made half-hourly settlement mandatory for profile classes 5 to 8 from April 2017. Those are the non-domestic "maximum demand" classes, whose metering has a register showing the maximum demand for a given period. Elexon notes that any of these sites still without half-hourly metering are settled using historic load profiles.

In practice, sites with a large agreed capacity, current transformer metering or high consumption are usually half-hourly. If you think a site should be half-hourly metered and is not, or you are adding load, Fidelity Energy can support the move to half-hourly metering alongside the business electricity contract itself.

Gas has no equivalent: half-hourly settlement is an electricity arrangement. Larger gas sites use advanced (AMR) meters that send readings remotely. See business gas.

Who runs a half-hourly meter

A half-hourly supply involves more parties than a typical small business supply, and some of them work under contracts you can see.

The meter operator contract is the one a business may hold directly. It can have its own term, scope and charges, separate from your supply contract, so it is worth checking when it ends and whether it covers data communications. Fidelity Energy offers managed meter operator contracts for half-hourly sites, covering installation, maintenance, data communications and supplier liaison. The industry roles behind half-hourly data are also being reshaped as part of market-wide half-hourly settlement, described below.

What half-hourly data tells you

Forty-eight readings a day per meter adds up to a detailed picture of how a site uses electricity. Used well, it helps with:

• Maximum demand and capacity. Half-hourly data shows your highest demand, which you can compare with the agreed supply capacity in kVA that drives electricity capacity charges. If demand regularly runs well below or above it, that is worth a conversation with your network operator.
• Out-of-hours use. Nights, weekends and holidays should show low use. Whatever still runs then is easy to spot.
• Time-of-day costs. Network charges and some non-commodity costs vary with when you use electricity. See non-commodity costs.
• Buying energy. Suppliers price half-hourly sites from their consumption profile, and the data underpins pass-through energy contracts and flexible energy contracts.
• Checking bills. Half-hourly bills carry more line items than small business bills, and the data lets you check that consumption and capacity are charged correctly.

Under government rules in force since 1 December 2022, any business customer, or a third party it nominates, can ask its supplier for up to 12 months of historic smart or advanced meter data free of charge, so you can have the data before you get quotes. Fidelity Energy offers half-hourly meter reporting and bill validation, so we can help you get the data into a form you can use. We do not promise what it will find: it depends on the site.

Market-wide half-hourly settlement (MHHS)

Market-wide half-hourly settlement is the industry programme to settle every electricity meter in Great Britain on half-hourly data, not just the larger sites. Ofgem placed responsibility for delivering it on the industry and appointed Elexon as the programme's Senior Responsible Owner.

Where the programme stands, from the MHHS Programme's own milestone page (October 2026):

October 2026 marked one year since migration began. The programme says the outcome will be faster and more accurate settlement, with site-specific reconciliation using half-hourly data.

MHHS is a change to settlement, carried out by suppliers and their agents: by M15 every supplier must have migrated all its MPANs. Non-smart metered MPANs are included, so the programme itself does not depend on every site getting a new meter. If you want to understand what it means for a specific contract, ask before you sign.

Half-hourly meter vs smart meter

The two are often confused. A smart meter (SMETS2) can record half-hourly consumption, and Ofgem's licence rules include obligations on suppliers to make that half-hourly data available to smaller business customers with a smart meter. But a smart meter on a small site is not the same as a half-hourly metered supply.

See smart meters for business for how smart and AMR meters work.

How we can help

Forever Communications acts as an agent introducing businesses to Fidelity Energy, an independent business energy consultancy and broker that offers meter operator contracts and half-hourly reporting. We help you pull together your MPANs, half-hourly data, agreed capacity and meter operator details, and explain what they mean. Fidelity Energy gets quotes from the suppliers it works with and arranges the supply contract you choose. Your supply contract is with the energy supplier, you decide whether to go ahead, and how we work with Fidelity Energy explains how commission is paid and shown.

To compare business energy prices across suppliers, our sister site explains the process. Ask us for a quote for your half-hourly sites. Need help with a half-hourly meter, its data or its meter operator contract? Contact us.