MHHS officially went live on 22 September 2025, marking a major milestone in the UK energy market transformation.
The UK energy market is undergoing a major transformation with the introduction of Market-wide Half-Hourly Settlement (MHHS). This reform will change how electricity consumption is measured and settled, bringing greater accuracy, transparency, and efficiency to the industry.
What is MHHS?
MHHS is a regulatory programme led by Ofgem that mandates all electricity meters in the UK to be settled using half-hourly consumption data. This replaces the traditional method of estimating usage based on profiles, enabling real-time insights into energy consumption.
Expected benefits:
- More accurate billing based on actual usage
- Improved energy forecasting and grid management
- Support for dynamic tariffs and flexible energy use
- Enhanced integration of smart meters and renewable energy
- Better data for achieving net zero goals.
MHHS Migration Timeline
MHHS Timeline Details
Not all suppliers will have completed the MHHS integration testing by October 2025. The System Integration Testing phase has experienced delays, and only a group of early adopters including central systems, DNOs, and selected suppliers will be ready to begin migration at that point.
Other suppliers will qualify through multiple waves of Qualification Testing, continuing throughout the migration period.
MHHS MPAN Calculator
We have developed a simple MHHS MPAN Calculator to help organisations understand their new MPAN format. Just enter your meter type and MPAN Core to see your updated structure to support the MHHS market structure.
Navigate MHHS with confidence
As MHHS introduces more granular data and complex billing structures, energy bureau services play a vital role in protecting organisations from overcharges and billing errors. With future pass-through charges likely to be harder to verify, our automated validation ensures accuracy and can recover up to nine times the service cost.