Last updated: Thursday 17 September 2026 (Europe/London).
Next update: when Ofgem or the MHHS programme publishes a material settlement milestone that changes SME meter duties.
By: Switch Editorial Team, Switch Squid Ltd
A half-hourly (HH) electricity meter records consumption every 30 minutes and feeds that data into industry settlement. In Great Britain, larger non-domestic sites with maximum demand above about 100 kW are expected to be on HH metering, and since 1 April 2017 Ofgem’s BSC modifications P272 / P322 required profile classes 5–8 with advanced meters to be settled using actual half-hourly data. This page explains HH vs NHH for UK businesses — without inventing SME pence-per-kWh list prices.
I am Switch. If you need a business energy quote after you understand your meter class, use SwitchSquid’s own form at /business-energy/ — that is the only correct primary CTA for this vertical (not an affiliate hub).
HH vs NHH in one table
| Topic | Half-hourly (HH) | Non half-hourly (NHH) |
|---|---|---|
| Read frequency | Every 30 minutes | Periodic / profiled estimates historically |
| Typical sites | Larger commercial / industrial, max demand ≥ ~100 kW; PC 5–8 | Smaller SME supplies, PC 3–4 historically |
| Settlement | Actual HH data into settlement | Moving toward HH under MHHS for smart meters |
| Extra charges | Often capacity, meter operator (MOP), data collector costs | Usually simpler standing structure |
| Tariff shape | Can support HH / flexible / pass-through products | Often fixed or simpler single rates |
Sources: Ofgem guidance “Moving to half-hourly energy reads (BSC P272 and P322)” and established industry summaries of the 100 kW maximum-demand rule. Always confirm your own MPAN profile class on the bill.
How to tell if you are already HH
Look at the profile class — the first two digits of the bottom line of your MPAN (supply number) on the electricity invoice:
- 00 — dedicated half-hourly settled supply
- 05–08 — non-domestic maximum-demand classes brought into HH settlement under P272
- 03–04 — standard non-domestic (historically NHH; MHHS changes the settlement layer over time)
If your maximum demand has crept above 100 kW (new machinery, EV chargers, HVAC upgrades), your supplier or DNO path may require an HH metering upgrade even if you still think of yourself as a “small” business.
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P272 / P322 in plain English
Ofgem’s guide explains that from 1 April 2017, businesses in profile classes 5–8 with advanced meters had to be settled on actual half-hourly consumption rather than estimates. P322 required suppliers to move customers onto HH settlement when they started or renewed contracts within set timelines from late 2015. The policy aim was better industry settlement and sharper incentives for demand management — not a consumer “gotcha”, but it did change how many mid-size sites were billed and quoted.
What HH changes about your quote
HH sites often see:
- Capacity / availability charges linked to agreed supply capacity (kVA)
- Meter operator and data service fees that NHH microbusiness quotes may bury or omit
- Richer time-of-use or flexible products that reward shifting load out of red bands
- More complex renewal packs — brokers and LOAs become common (see our letter-of-authority guide)
We will not print a fake “typical SME HH unit rate 24.2p” — those numbers are site-specific and quote-only. Bring 12 months of HH data (or at least monthly kWh + MD) to any broker or supplier tender.
Market-wide Half-Hourly Settlement (MHHS)
MHHS is the industry programme extending half-hourly settlement across smart and advanced meters, not only classic 100 kW HH sites. Timelines have moved through industry milestones toward the later 2020s; treat programme dates as regulatory context and verify the latest Ofgem / code-body update when you plan a multi-year contract. For a microbusiness on a smart meter, the customer-visible change may be modest; for settlement and supplier pricing models, it is structural.
When to upgrade voluntarily
Below the mandatory threshold, some sites still choose advanced / HH-capable metering to unlock flexibility products, solar export accuracy, or EV depot management. Weigh MOP costs against the tariff benefit. If your load is flat and tiny, NHH simplicity can still win.
Quote checklist before you tender
- Photograph the MPAN and note profile class.
- Export 12 months of consumption (HH CSV if you have it).
- Note contracted capacity kVA and any reactive power charges.
- List site constraints (24/7 cold store, shift patterns, EV chargers).
- Decide LOA scope if using a broker — never sign a vague LOA.
- Submit via switchsquid.com/business-energy/ or your preferred authorised route.
Capacity, kVA and the silent bill line
Many HH invoices show an agreed supply capacity in kVA. Exceed it and you can face excess capacity charges; oversize it and you pay for headroom you never use. After installing EV chargers or a new kitchen plant, revisit capacity with your DNO / supplier rather than discovering the charge on month three of a “cheap” unit rate.
Reactive power (kVArh) charges appear on some HH sites with poor power factor. Correcting power factor can save more than a 0.2p unit-rate win. Ask your tender counterparties to itemise capacity, reactive, CCL, FiT, meter ops, and data services separately from the energy rate.
Brokers, LOAs and HH data packs
HH tenders often travel through brokers armed with a Letter of Authority. Limit LOA scope (suppliers, duration, whether they may serve notice). Provide HH data packs as CSV rather than blurry PDF bill photos — better data means sharper quotes and fewer “estimated” tenders that miss your night load.
If two brokers request LOAs, assume chaos. One authorised route at a time is enough. SwitchSquid’s business form is designed for direct quote handling without forcing you into an opaque LOA chain.
Flexibility, DSR and the HH advantage
Half-hourly visibility unlocks demand-side response, triad-era thinking (even as charging methodologies evolve), and private-wire / behind-the-meter strategies. Warehouses that can pre-cool, or factories that can shift a furnace cycle, monetise HH data. A retail shop with flat 9–5 load may gain little beyond compliance.
Pair HH metering with sub-metering on big assets if you intend to act on the data. A single gate meter tells you the site total; it does not tell you which compressor to fix.
Gas meters and the electricity-only story
This guide is about electricity half-hourly metering. Gas AMR / daily metered sites follow different thresholds and product codes. A site can be HH on power and simple on gas — or the reverse. When you tender dual fuel, label each MPAN/MPRN clearly so brokers do not mix settlement types.
Deemed and out-of-contract HH rates can be punitive because the supplier’s risk and imbalance costs are higher without a negotiated shape. If your fixed HH contract ends in the next 90 days, start the tender now — not the week after deemed kicks in. Soft reading: our out-of-contract and deemed business electricity guides from earlier sprint days.
Document ownership of metering assets: some HH MOPs are appointed separately from the supplier. When you switch supplier, confirm whether the MOP appointment migrates cleanly to avoid a week of estimated reads during the handoff.
For multi-site groups, standardise how HH CSVs are filed (site code, MPAN, date range) so group procurement can tender like-for-like. Messy data is why “framework” deals sometimes look cheap until capacity charges appear.
Train one person on each site to pull HH data monthly even when you are not tendering. Waiting until renewal week to discover missing intervals is how businesses accidentally accept weak deemed rates.
If you operate landlord supplies or multi-let estates, separate HH MPANs per demise wherever practical so tenants’ load shapes do not distort the landlord’s flexibility options.
Keep regulator bookmarks handy: Ofgem’s P272/P322 business guide remains the clearest official explainer of why profile classes 5–8 moved to half-hourly settlement in 2017. Pair it with your latest bill when you brief a finance director who still thinks “smart meter” and “half-hourly meter” are the same device.
FAQ
What is a half-hourly meter?
An electricity meter that records use every 30 minutes for settlement and billing.
When is an HH meter mandatory?
Industry practice ties mandatory HH metering to maximum demand above ~100 kW; P272 also forced HH settlement for profile classes 5–8 with advanced meters from April 2017.
How do I know my profile class?
Read the first two digits of the MPAN bottom line on your bill (00, 03–04, 05–08, etc.).
Does HH mean higher bills?
Not automatically — unit rates can be competitive — but capacity and meter-service charges can raise the standing cost stack.
What is MHHS?
Market-wide Half-Hourly Settlement — the programme moving more meters onto HH settlement using smart/advanced data.
Can a small office stay NHH?
Many microbusinesses historically did on PC 3–4. Confirm your class and supplier letters; smart-meter MHHS may change settlement without a classic “HH meter install” drama.
Will you quote a p/kWh on this page?
No. Business rates are quote-only. Use the form.
Where do I get a SwitchSquid quote?
https://www.switchsquid.com/business-energy/
Get a business energy quote now →
Regulatory guidance summarised for education — not a substitute for your supplier contract or DNO notices.
