Market-wide Half-Hourly Settlement (MHHS): What the Rollout Means for Your Business

What market-wide half-hourly settlement changes for your business, and how to turn granular half-hourly data to your advantage.

One of the biggest reforms of the electricity market in years is happening quietly in the background. Market-wide Half-Hourly Settlement will change how every meter in Britain is settled, and it makes when you use power matter more than ever.

What MHHS Is

Market-wide Half-Hourly Settlement, or MHHS, is one of the biggest behind-the-scenes reforms of the electricity market in years. It changes the way every meter in Britain is “settled”, the process by which suppliers reconcile how much energy their customers actually used against what they bought from the wholesale market. Today, only larger half-hourly sites are settled on the basis of their true half-hourly consumption; most smaller meters are settled using estimated load profiles. MHHS moves the whole market onto actual half-hourly data, using the information smart and advanced meters already collect.

It is a technical change, but it has real commercial consequences, because settling on genuine half-hourly consumption sharpens the link between when you use electricity and what it costs. That is the same principle that already drives several of the non-commodity charges on a business bill, and it sits within the wider stack of non-commodity costs that shape what you actually pay.

Why It Is Happening

The reform is being delivered under Ofgem’s oversight and is being rolled out on a phased basis, with the industry migrating meters across to the new arrangements through the mid-2020s. The rationale is that a smarter, more flexible grid needs accurate, granular data. When suppliers can see exactly when demand occurs, they can offer tariffs and services that reward customers for using power at cheaper, greener times, and the system as a whole can integrate more renewable generation and flexibility. You can read about the programme on Ofgem’s MHHS pages.

In short, MHHS is part of the same journey towards a time-based, flexible electricity market that gave rise to the government’s wider reforms of how power is priced and traded.

What Changes for Business

For businesses already on half-hourly metering, the mechanics of settlement change but the day-to-day experience is largely the same. The bigger shift is for smaller non-half-hourly sites, which will increasingly be settled on actual consumption as their smart meters feed genuine half-hourly data into the system. Practically, this means the time profile of your consumption, not just the total, becomes more visible and more relevant to what you pay. Businesses that draw a lot of power at peak times may find that pattern reflected more sharply in their costs, while those that can shift usage to cheaper periods stand to benefit.

This reinforces a trend business energy buyers already know well: managing when you use energy is becoming as important as managing how much. It is the same logic that rewards demand side response and time-of-use strategies.

The Opportunity in Half-Hourly Data

The flip side of more granular settlement is more granular insight. Half-hourly data is a powerful management tool: it shows exactly when your site draws power, reveals peaks you can target, and underpins decisions on everything from shifting production to installing on-site generation or storage. As MHHS makes this data central to how you are billed, the businesses that actually use it, rather than filing it away, will be the ones that turn the reform to their advantage. On-site flexibility such as battery storage becomes more valuable in a world where the timing of demand is priced more precisely.

How to Prepare

There is no action required simply to comply, the migration happens through the industry and your supplier. But there is plenty you can do to be ready to benefit. Make sure you have access to your half-hourly data and understand your consumption profile. Identify whether your peaks can be shifted or shaved. And factor time-of-use thinking into your procurement, so your contract structure lets you capitalise on flexibility rather than paying a flat premium for it. A flexible approach through energy procurement is well suited to a market that increasingly prices energy by the half-hour.

What This Means for Your Business

MHHS is a plumbing change with commercial consequences: by settling the whole market on real half-hourly data, it makes the timing of your consumption matter more than ever. You do not need to do anything to comply, but the businesses that understand their half-hourly profile and structure their buying and operations around it will be the ones that come out ahead as the reform beds in.

If you would like help making sense of your half-hourly data and positioning your energy strategy for a time-of-use market, our team can analyse your profile and model the opportunities. Get in touch to speak to one of our energy consultants today.