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Competitive PricesHalf-hourly electricity meters, what they are, when they’re mandatory, and how to install one
A half-hourly (HH) meter is an electricity meter that records consumption every 30 minutes and sends that data automatically to your supplier and the wider energy industry. They’re mandatory for UK businesses with peak electricity demand above 100 kW. Below that threshold, they’re optional, but increasingly common as suppliers move customers onto smart metering and as half-hourly settlement (HHS) rolls out across the industry.
Here’s what you actually need to know, in 2026.
When you legally need a half-hourly meter
If your site’s maximum demand exceeds 100 kW, half-hourly metering is mandatory. Your DNO calculates your maximum demand from your historical consumption data. Once you breach the threshold consistently, the industry triggers an upgrade requirement.
You can also voluntarily request an HH meter at lower demand levels, typically worth it if you have variable demand patterns and want granular data for contract negotiation.
What “100 kW” means in practice
| Business type | Typical peak demand |
|---|---|
| Small office (under 20 people) | 10 to 30 kW |
| Medium office or retail unit | 30 to 80 kW |
| Pub or small restaurant | 30 to 80 kW |
| Larger restaurant / small hotel | 80 to 150 kW |
| Light manufacturing | 100 to 500 kW |
| Industrial sites | 500 kW to several MW |
If you’re approaching 100 kW peak, you’ll cross the threshold sooner than you think. Plan for HH metering proactively, a planned upgrade is cheaper and less disruptive than a forced one.
What HH metering unlocks
Three real benefits beyond regulatory compliance:
- Granular consumption data. HH meters give you 48 data points per day. You can identify overnight loads, weekend leaks, and process inefficiencies that flat-rate billing hides completely.
- Access to more competitive contract structures. Half-hourly settled supplies can get pass-through, flex, and load-based contracts that aren’t available to non-HH customers. For businesses with variable demand, these contracts can save 5 to 15% versus a fully fixed-rate contract.
- More accurate forecasting. Annual budget planning becomes a real exercise rather than a guess. You know exactly when your spikes hit and can plan for them.
What HH metering costs
Upfront install cost: typically varies by supplier and MOP depending on site complexity and what equipment already exists.
Ongoing standing charges (the MOP / Meter Operator contract): typically varies by supplier and MOP per year, sometimes higher for complex sites. This is on top of your supplier’s daily standing charge.
Compare that to a standard non-HH meter, which has no MOP standing charge (or a much lower one). The ongoing additional cost is real, but for sites above the 100 kW threshold, it’s mandatory regardless.
How long an HH install takes
| Stage | Duration |
|---|---|
| Order placed with supplier or MOP | Day 1 |
| Site survey scheduled | Week 1–2 |
| Survey completed, install scheduled | Week 2–4 |
| Install + commissioning | Week 4–6 |
| First HH data flowing | Week 6–8 |
Total: 4 to 8 weeks for a clean install. Sites needing supply isolation, additional wiring, or DNO involvement can run 8 to 12 weeks.
Choosing a MOP for your HH meter
This is the bit most businesses don’t realise: you can choose your Meter Operator independently of your supplier. The MOP owns and maintains the HH meter and charges you a standing fee for the service.
Suppliers usually have a default MOP they prefer, but if you’re an HH-metered site, you have the right to put the MOP contract out to tender. We compare MOPs as standard when we’re sourcing HH installs for clients, savings of varies by supplier and MOP per year on the MOP contract are typical.
Things that catch people out
- You can’t go back. Once you’re HH-metered, you stay HH-metered. There’s no “downgrade to a normal meter” option even if your demand later drops.
- HH data is yours. You’re entitled to your HH consumption data from your MOP at any time, in usable format. Some MOPs are better than others at providing it cleanly.
- HH meters need a stable comms connection (typically GSM or fixed-line). If your site is in a poor-signal area, your install may need a different solution.
Working with Clearsight on an HH install
We coordinate the whole project: confirming the install is the right call, sourcing competitive MOP quotes, scheduling the install around your business operations, and getting the supply contract aligned to the new meter setup. No upfront fees.
Get a half-hourly meter install quote in 60 seconds.
Related guides: Business electricity meter installation, Meter operators (MOPs), Business meter installation hub, Business electricity pillar.
How is the 100 kW threshold for half-hourly metering measured?
The 100 kW threshold is based on your maximum demand, the highest half-hour of consumption recorded over a settlement period. It is not your average use or your annual kWh figure. A site can have a moderate annual consumption but still exceed 100 kW for a single peak half-hour, and that triggers the half-hourly requirement. If your business has any significant short-term load (commercial kitchen at lunch service, manufacturing process kicking in, large cooling demand on a hot afternoon), the peak is what counts.
What are Profile Class 5 to 8 and P272?
Under Ofgem regulation P272 (effective from April 2017), all UK business electricity supplies in Profile Classes 5, 6, 7 and 8 must be settled half-hourly. Profile Class 5 covers small to medium commercial, Class 6 covers medium commercial, Class 7 covers larger commercial, and Class 8 covers the largest non-domestic supplies. These classes overlap closely with the 100 kW peak demand threshold, which is why most businesses think of them as the same rule.
What changes when MHHS rolls out in December 2026?
Market-wide Half-Hourly Settlement (MHHS) is a regulatory programme rolling out from December 2026. From that point, any supply with a smart or advanced meter will be settled half-hourly, regardless of demand level. The 100 kW threshold remains the legal trigger for installing an HH meter, but the settlement layer underneath it changes for everyone. For sites already on smart meters, the practical impact is small. For sites on traditional metering, the change accelerates the shift to smart and AMR. See our MHHS guide for UK businesses for the full detail.
Who do you appoint when your business goes half-hourly?
On a half-hourly supply you have three appointments: the supplier (who bills you for energy used), the Meter Operator or MOP (who installs and maintains the meter), and the Data Collector or DC (who collects and validates the half-hourly data). The DC is usually bundled with the MOP appointment, but for larger sites it can be appointed separately. Some businesses pick a single MOP across all their sites for consistency, others pick per-site for best price. We can quote both routes.
What are the operational benefits of a half-hourly meter?
Half-hourly data is useful even if you are not legally required to have it. The granular consumption pattern lets you spot overnight or weekend use that should not be there, catch tariff billing errors before they snowball, tighten your forecasting against actual usage rather than estimates, and qualify for the contract structures (pass-through, flexible procurement) that need accurate demand-by-half-hour data. For sites approaching 100 kW, opting into half-hourly voluntarily can be a sensible move ahead of a forced upgrade.
What is the difference between a CT meter and a whole-current meter?
Half-hourly meters at higher load levels are usually CT-metered (Current Transformer). A CT meter measures the load indirectly via transformers fitted around the supply cables, which is required where the load exceeds the direct-connected meter range (typically over 100 amps per phase). The install is more involved than a whole-current swap because the CT clamps go onto live conductors and need scheduled isolation. Plan this in advance.
Related Clearsight guides on half-hourly metering
For the full picture on meter installs and connections, see our business meter installation and new connections hub. For broader supply-side decisions once your half-hourly meter is fitted, see our business electricity pillar. For the upcoming settlement reform, read the MHHS guide.
What is Market-wide Half-Hourly Settlement (MHHS) and how does it affect my business?
MHHS is the largest electricity settlement reform since the market was deregulated. It changes the way suppliers buy and settle electricity for every smart-metered or advanced-metered site in the UK. Today, only Profile Class 5 to 8 sites (the ones above 100 kW) are settled half-hourly. Under MHHS, that becomes every site with a smart or advanced meter, regardless of demand profile.
For your business, the practical impact depends on what you have now. Sites already on a half-hourly meter see no operational change, just a wider market context. Sites on smart meters (SMETS2) start being settled half-hourly under the new arrangements, which means suppliers will price in your actual time-of-use consumption rather than an estimated profile. That can be good news for businesses with predictable demand and bad news for sites with peakier loads if they have not optimised their consumption pattern.
If you are still on a traditional non-smart meter, the timeline is more urgent. Suppliers are accelerating smart and AMR meter rollouts ahead of MHHS to bring sites into the new settlement framework. If your supplier offers an upgrade, taking it gets you under the new arrangements earlier and avoids a forced upgrade later.
How does half-hourly metering affect business electricity procurement?
Half-hourly data unlocks contract structures that fixed-rate buyers do not have access to. Pass-through contracts let you pay the wholesale market price plus a transparent margin, with non-commodity charges separated out. Flexible procurement lets you buy your energy in tranches across the year, hedging against price spikes when the wholesale market is volatile. Both require half-hourly data so the supplier can settle accurately against your actual consumption.
If your maximum demand is above 100 kW you are already in the half-hourly bracket. For sites that are voluntarily moving onto half-hourly metering, the procurement decision is worth taking before you sign the install. We sometimes see businesses pay for an HH meter install and then leave the contract as a basic fixed rate, missing the value the meter unlocks.
What does it cost to install and run a half-hourly meter?
HH meter installs carry higher install fees and higher ongoing standing charges than a non-half-hourly meter. The install itself is the smaller of the two costs. The ongoing standing charge (the MOP contract, plus a separate Data Collector contract on larger sites) is the bit that shows up on every bill. We get quotes from a panel of MOPs and Data Collectors, so the standing charge stays competitive rather than the default bundled rate.
Related Clearsight guides on electricity and connections
For a brand-new electricity connection at a site that does not yet have a supply, see our new business electricity connection guide. For the wider picture on meter installs and new connections (electricity and gas, including upgrades and smart meter rollouts), see our business meter installation and new connections hub. For the upcoming settlement reform in detail, read the MHHS guide for UK businesses.