Guides · Metering

Half-hourly vs non-half-hourly meters

Utilities Made Simple · 6 minute read

Business electricity supplies fall into two camps: half-hourly (HH), where your meter records consumption every 30 minutes and sends it automatically for settlement, and non-half-hourly (NHH), where your usage is estimated against a standard profile between readings. Which camp you're in decides how you're quoted, how fast, and by whom.

How to tell which you have

Check the profile class — the first two digits in the S box on your bill. 00 means half-hourly. Profile classes 03–04 are standard non-domestic NHH supplies, and 05–08 were the old maximum-demand classes. If your bill shows detailed consumption by time period, or you've ever been asked about "capacity" or "kVA", you're almost certainly HH.

Why HH is mandatory for some sites

Any supply with a maximum demand of 100kW or more must be half-hourly metered — that's been the rule for large sites for years. Then P272, an industry change completed in 2017, moved profile class 05–08 supplies onto half-hourly settlement too. If your site was 05–08, you may have become HH without changing anything yourself — and if you're still being renewed like an NHH site, your pricing may not reflect how you're actually settled.

How pricing differs

	NHH	HH
Quote basis	Published price matrices by region and profile	Bespoke price built from your actual half-hourly data
Quote speed	Usually same day	Days — data must be gathered under an LOA first
Price validity	Typically days to weeks	Usually the day of issue only
Extra charges	Rolled into unit rates	Capacity (kVA), DUoS time bands and levies often itemised

What this means at renewal

For NHH supplies, shopping around is fast — a same-day comparison is normal. For HH supplies, the winning move is preparation: letter of authority signed and consumption data gathered before the pricing day, so when bespoke prices land you can decide while they're still valid. That preparation is exactly the work a consultancy exists to do.