Market-Wide Half-Hourly Settlement (MHHS)
Bringing you up to speed on the major industry reforms and what they mean for your business.
What is MHHS?
MHHS is a programme of major industry reforms led by the energy regulator, Ofgem, to modernise the electricity system and its processes.
The industry is working together to move to MHHS in phases between September 2025 and July 2027.
What's changing?
Most changes will take place behind the scenes.
The main industry changes include:
- Half-Hourly (HH) Settlement for all MPANs. This is currently only required for the largest industrial and commercial consumers
- Changes to market structure and services. All agents and processes will be replaced with new market segments and new data and metering services to deliver MHHS
What MHHS means for your business
MHHS Migration: Changes to Services and Charging
We will contact you directly to let you know we're starting migration and once you have successfully migrated.
If your metering and/or data provider is not MHHS-compliant, we will manage your transition to the new metering and data services.
Potential impacts for your business
The impacts MHHS may have on your business depends on the type of meters you have and the services you use.
Once your MPANs are migrated to MHHS, the main practical changes you may notice include:
- Changes to billing – such as new read types
- A new settlement window of 4 months from the current 14 months
- More accurate settlement based on HH data for all your MPANs
- New terminology and services
- MPANs reclassified into new segments – ‘Smart’, ‘Advanced’ or ‘Unmetered’
- Introduction of new Metering & Data Service providers
Potential benefits
MHHS will bring benefits to businesses with meters capable of recording HH consumption and sending it to your supplier, such as DCC-enrolled smart or Automatic Meter Reading (AMR) meters:
- Gain accurate, HH data insights for all your meters to help manage your energy
- Access to the latest smart products and tariffs, including flexibility, battery storage and EVs
- Avoid more frequent engineer visits carrying out manual HH data downloads
Why MHHS?
MHHS aims to provide a more accurate picture of electricity consumption across the UK based on Half-Hourly (HH) data provided by modern meters. Ofgem expects this to encourage more flexible energy use, support our transition to a net zero future and lower bills for all users.
Smarter data insights for all users
MHHS will provide more accurate, timely insights into electricity consumption for all users, based on HH data.
This will help the industry understand consumption, predict demand and meet future energy needs.
Greater flexibility to support net zero
Better data will incentivise suppliers to offer new products and time-of-use tariffs based on flexible energy use. Encouraging customers to shift their energy use to off-peak times helps reduce demand for carbon-intensive generators like gas turbines.
Cost-saving opportunities
Engaging with new flexibility schemes and smart tariffs will help businesses lower their energy bills by changing how they use energy.
Ofgem predicts MHHS will deliver consumers a net benefit of £1.5b to £4.5b by 2045.
Make sure you're MHHS-ready
For most businesses, the best way to prepare for MHHS is to upgrade any NHH meters on your sites to smart or AMR meters. Upgrading now could mean you get better benefits, sooner.
Ask your account manager to check any next steps you may need to complete, or get in touch about upgrading your business to smart metering using the links below.
What are the key industry changes under MHHS?
MHHS will transform the electricity system and its processes. These ongoing changes are mandated from Ofgem's central MHHS programme and will impact all suppliers and industry participants.
MHHS will create a more accurate and efficient settlement process based on Half-Hourly (HH) consumption data.
- All MPANs will be settled using Half-Hourly data regardless of meter type. This is currently only required for the largest industrial and commercial consumers.
- Settlement timescales will be shortened from 14 months down to around 4 months. This will be the last change in the MHHS programme, due in July 2027.
All Non-Half-Hourly (NHH) agents and processes will be replaced with new market segments and services to deliver MHHS.
- Changes to market segments - The market will be split by meter type (‘Smart', 'Advanced' and 'Unmetered’) instead of by measurement class, which helped identify HH vs NHH or Metered vs Unmetered.
- New Data & Metering Services - Data and Metering Service Providers will replace agents e.g. 'DC', 'DA', 'MEM', 'MOP’. The current DC/DA services become Data Services (e.g. Smart Data Service, Advanced Data Service and Unmetered Supply Data Service. The current MEM/MOP will become Metering Services (Metering Service Smart, and Metering Service Advanced).
To comply with MHHS, all suppliers, meter operators and data providers are going through a ‘qualification’ process to adapt to new processes and increases in data. As a Meter Operator, we’re getting ready to become a Metering Service Provider.
How will MHHS affect my business?
Most changes will take place behind the scenes and will impact all industry participants. Commercial details will be worked out as the programme is delivered across the industry.
The impact on your business depends on the type of meters and services you use. We’ll be in touch to explain exactly how any changes may affect you.
Once your MPANs are migrated to MHHS (for our customers, this will be up to May 2027, you may notice practical changes:
- Settlement changes: More accurate settlement based on HH data for all your meters;
- Changes to billing - Updates to bills, quotes and contracts - possible cost changes due to the difference between NHH and HH metering and settlement
- New terminology: MPANs reclassified into new segments - 'Smart', 'Advanced’ or 'Unmetered’; New Metering and Data Service Providers to replace existing agents ('MOP', 'MEM', 'DA', 'DC')
As MHHS progresses, it will bring potential benefits for businesses with meters capable of recording HH consumption and sending it to your supplier, such as DCC-enrolled smart or Automatic Meter Reading (AMR) meters:
- Better data insights - MHHS will provide you with Half-Hourly data for all your meters, which can help with managing your consumption and energy efficiency
- Cost-saving opportunities - Engaging with new ‘flexibility’ products and tariffs will help you save money by changing how you use your energy
You’ll need smart or AMR meters to access these benefits. Get in touch - we can help upgrade your meters to get your business ready.
When will the changes happen?
When will the changes happen?
Ofgem’s central MHHS programme is in ongoing development, so timings are subject to change - this affects all electricity industry participants.
MHHS is taking place in stages with changes going live between September 2025 and July 2027. Most changes will happen behind the scenes.
Preparation phase (ongoing)
To comply with the new MHHS model, all suppliers, metering operators and data providers are undergoing a ‘qualification’ process.
Migration phase
The move to Half-Hourly (HH) settlement will take place during an industry-wide 'migration' period, affecting all suppliers and industry participants:
- September 2025 - Migration starts across the industry
- May 2027 - Ofgem's deadline for migration (all MPANs must be settled Half-Hourly)
- July 2027 - Ofgem’s target for MHHS completion – the industry moves to a four-month settlement timetable
Why the move to Half-Hourly settlement?
The key change under MHHS is the industry-wide move to ‘Half-Hourly’ (HH) settlement. This involves making the most of Half-Hourly (HH) consumption data to provide a more accurate view of the costs of electricity.
Currently, HH settlement is only required for the largest industrial and commercial consumers. Most of the market is settled based on several Non-Half-Hourly (NHH) consumer data profiles, which are increasingly outdated.
Unlike traditional NHH meters, the latest smart and advanced meters can record consumption data up to every half-hour. As smart meters replace NHH meters across the UK, there is an increasing amount of HH data in the system, which provides a more accurate, timely view of modern consumption patterns.
MHHS will use this smart data as the basis for settlement for all MPANs, no matter the meter type.
The move to HH settlement will:
- Give suppliers a better understanding of the true costs of supplying your electricity
- Help to improve settlement accuracy
- Encourage flexible tariffs and services
Why the move to smart metering and AMR?
Unlike traditional NHH meters, the latest smart meters can provide precise, timely insights by recording consumption data up to every half-hour. This helps to make the energy system smarter and more efficient.
Smart meter data plays a key role in the transition to net zero by supporting important innovations like flexibility, battery storage and electric vehicles. We offer a range of products and services to help businesses make the most of these emerging ‘smart grid’ technologies.
We can help you upgrade to smart metering and discuss our wider offerings to help your business achieve net zero.
What do I need to do to prepare?
There isn’t anything you need to do, we will be in touch when we are migrating your business and once migration has been successful.
What is a migration?
The MHHS migration will happen behind the scenes and you don’t need to take any action, as it is mainly a change of agent. There could be updates to your metering and data services, including how services are structured and how charges are applied.
Why could a migration fail for a customer?
This could be due to incorrect data being held with either the supplier, Meter Operator or the Data Collector. EDF will be taking the necessary steps to ensure our customer’s accounts are ready for migration.
How will I know when I have been migrated?
EDF will confirm to you directly to confirm you have been successfully migrated to MHHS.
Also you will receive a bill for the pre-migration period and post migration. This is to clearly change your account over to Half-Hourly where possible.
How can I find out more?
Stay tuned for more insights and updates about MHHS on this webpage.
If you are an EDF business customer, you will receive communications directly from us expanding on MHHS in more detail.
Stay up to date
Keep an eye out for upcoming webinars and blogs on MHHS over on our TalkPower page.
