MHHS made simple: what it means for your business

28/10/26

A big change to how business electricity is measured and billed, called MHHS is currently taking place, which will affect every business with an electricity supply.

What is MHHS?

MHHS stands for Market-wide Half-Hourly Settlement. Historically, electricity suppliers have calculated a small site’s consumption by deducting two sets of meter reads from each other. However, this legacy method meant large periods could be estimated by a supplier, if no actual meter readings were provided.

Instead, the introduction of MHHS aims to increase the availability of actual electricity consumption data to both supplier and consumer, which is measured and downloaded from the meter every 30 minutes (using the same process which large business have for decades).  This national programme is led by the energy regulator, Ofgem, whose goal is to provide a fairer, smarter, greener energy system based more accurate billing.

When is it happening?

Suppliers are now moving their customers across in stages, and every customer should be switched over by spring 2027. Your supplier will handle the move itself, and each supplier has its own timetable – so if you have several sites with different suppliers, the supplies may migrate at different times.

Even if you already have half-hourly meters, you will still be moved onto the new system.

What will it look like?

For most businesses, the changeover itself will be fairly non-eventful, but you should expect:

• Fewer estimated bills and so fewer later adjustments
• New wording may appear on your bills and contracts.
• A closer link between when you use energy and what it costs, so electricity used at busy times costs the system more. With half-hourly data, that becomes far more visible, and your costs will increasingly reflect when you use power, not just how much.
• More tariffs that reward you for using electricity at cheaper times.

How IEC can help with MHHS

At IEC, we are keeping track of the changes MHHS involves. We can:

• check which of your sites need meter upgrades or if any have faulty smart meters, and help get them installed;
• keep an eye on your bills during the switchover and beyond and challenge anything that doesn’t look right;
• turn your half-hourly data into clear, practical advice on where you could save; and make you more informed about your business energy consumption;
• help you choose the right contract at your next renewal, now that timing your activity matters more.

Gavin Williams, IEC Energy Manager, says: 

“MHHS sounds technical, but the idea behind it is simply billing based on what you actually use, rather than estimates. This will allow organisations to have a greater understanding of their energy usage profile and should enable them to reduce energy usage & costs in the future.”

Get in touch with the IEC team to find out more.