What will Market-wide Half-Hourly Settlement (MHHS) mean for businesses in 2025?

This year marks the start of Market-Wide Half-Hourly Settlement (MHHS) - affecting all businesses and industry participants in the UK. MHHS is a national initiative being led by Ofgem to transform how we all use and account for electricity. 

While most changes will happen behind the scenes - work is already well underway across the industry - there will be important impacts and opportunities for consumers. Changes will start going live from September 2025, with all consumers  ‘migrating’ to MHHS over 18 months from October 2025 (dates are subject to change depending on Ofgem’s central MHHS programme). 

To help make sense of it all, we’ve outlined what businesses need to know to prepare for MHHS in 2025.

Changes to settlement, billing and market terminology

The practical impacts of MHHS will depend on the types of meters and services businesses currently receive. MHHS will move all MPANs to Half-Hourly (HH) settlement, regardless of the type of meter. Until now, this has only applied to the largest of energy consumers. 

HH settlement uses more detailed, timely data from smart and advanced meters to give a more realistic picture of energy consumption for every meter. 

Moving to HH settlement will mean:

• More accurate settlement based on HH data for all your MPANs;
• Potential changes to billing, quotes and contracts – costs may change in line with HH metering. 

MHHS will see the introduction of new terminology and services to help modernise the industry and deliver MHHS. All Non-Half-Hourly (NHH) agents and processes will be replaced. For instance, you may notice:

• The introduction of new Metering and Data Services providers to replace existing agents ('MOP', 'MEM', 'DA', 'DC');
• New market segments - All MPANs will be reclassified as 'Smart', 'Advanced’ or 'Unmetered'.

Potential benefits for smart businesses

The more businesses engage with MHHS, the greater their potential rewards. 

Ofgem expects MHHS to bring £1.5b to £4.5b in net benefits for British consumers by 2045. 

Businesses with smart or AMR meters will be able to benefit from:

• Smarter data insights - MHHS aims to provide more accurate, timely insights into electricity consumption for all users. Businesses can gain accurate, Half-Hourly data for all meters to help understand their energy usage, predict demand and meet future energy needs.
• Access to cost-saving opportunities - Better data will lead to new products and time-of-use tariffs based on flexible energy use, helping to support our transition to a net zero future. Engaging with new flexibility schemes and tariffs will help businesses lower their energy bills.
• Less hassle - Upgrading legacy NHH meters also means businesses will avoid extra engineer visits for manual data downloads once MHHS takes effect.

To access better benefits from MHHS, sooner, businesses need ‘smart’ meters capable of recording HH data, i.e. smart (SMETS2), AMR or HH meters. 

The end of 2025 will also mark another important industry milestone: the deadline for the government’s smart meter mandate, with binding targets for suppliers to upgrade their customers’ non-smart meters to smart or advanced meters. 

For businesses, having ‘smart’ metering will become increasingly important as a prerequisite for accessing the latest benefits and opportunities within the flexibility, EV, and battery storage markets.

By taking action to prepare now, businesses can be first in line to reap the benefits of better data, flexible tariffs and potential cost-savings.

Prepare now to get ahead - we can help 

Our in-house experts offer a bespoke service to help businesses navigate the changes and opportunities coming up in 2025, from MHHS to smart metering. We can upgrade any legacy NHH meter(s) across your sites to ensure your business is ready to access the benefits of MHHS and new flexible tariffs.

Get in touch with your EDF account manager to check next steps for your business.