Why Market-Wide Half-Hourly Settlement will reshape the UK electricity market

Insights

The UK’s electricity system is on the verge of one of its largest reforms in decades: moving from a system where many consumers’ usage is estimated (or averaged) to one where every meter is settled half-hourly. This transition, known as Market-Wide Half-Hourly Settlement (MHHS), promises more accurate billing, greater flexibility, and a cleaner, smarter grid. But the change also brings challenges, costs, and risks.

What is MHHS?

Under the current system, only large consumers (or those already on “Half-Hourly” meters) have their usage recorded in 30-minute slices (“settlement periods”). Many residential and smaller non-domestic consumers are on Non-Half-Hourly (NHH) settlement, meaning their usage is estimated using standard profiles.

MHHS changes this: all meters will be settled on actual half-hourly data rather than estimates. This requires smart or advanced meters and a complete redesign of market systems to handle far more granular data.

Migration begins in October 2025, with full implementation by mid-2027.

Why MHHS? The Case for Change

  1. Better Accuracy & Fairness

Half-hourly data removes the guesswork inherent in profile-based estimation, leading to fairer billing that reflects real consumption patterns.

  1. Enabling Flexibility & Innovation

With more granular data, suppliers can offer time-of-use tariffs or incentives for shifting usage. This paves the way for innovations like EV smart charging, battery storage, and demand response.

  1. Supporting Net Zero Goals

A low-carbon, renewable energy system depends on flexible demand. MHHS provides the pricing signals and data infrastructure needed for that flexibility.

  1. Reducing Market Risk & Cost

Quicker settlement (from 14 months to around 4) reduces supplier exposure and systemic cost, leading to a more efficient market overall.

Impacts & Challenges

Implementation Costs & Data Complexity

Suppliers and data agents will need to upgrade systems and processes to handle vast amounts of real-time data, increasing operational complexity.

Metering Infrastructure

The success of MHHS depends heavily on the completion and quality of the smart meter rollout. Businesses without compliant meters will need upgrades.

Tariff & Contract Changes

With billing based on actual half-hourly use, pricing will reflect when electricity is consumed potentially increasing costs for users with heavy peak-time demand but creating savings opportunities for those who can shift load.

Customer Engagement

Education is key. Without understanding flexible tariffs and time-of-use signals, many customers risk missing the potential savings and carbon benefits.

 

What’s Happening Now (2025–2027)

  • Central settlement systems are live as of September 2025.
  • MPAN migration begins October 2025 for early supplier cohorts.
  • By mid-2027, all meters are expected to be settled half-hourly.
  • Suppliers, brokers, and consumers should use 2025–2026 to prepare systems, data processes, and strategies.

 

How eyebright Can Help

At eyebright, we help organisations and consumers turn regulatory change into opportunity. MHHS will reshape how energy is priced, managed, and optimised and our team is ready to guide you through it.

  1. Metering and Data Readiness

We can assess your current metering estate and identify where upgrades or reconfiguration are required. Our experts ensure your meters and data flows are compliant and capable of providing accurate half-hourly data for settlement.

  1. Tariff & Contract Strategy

Half-hourly settlement opens up new tariff structures and risk profiles. We help you review your energy contracts, model different time-of-use pricing scenarios, and negotiate the most cost-effective agreements with suppliers.

  1. Energy Data Analytics

eyebright’s analytical tools turn complex half-hourly data into actionable insights. We help you understand consumption patterns, identify inefficiencies, and unlock opportunities for savings through demand shifting and on-site generation.

  1. Demand Flexibility & Sustainability

Our consultants can design flexibility strategies such as load shifting, battery integration, or EV smart charging that allow you to benefit from cheaper off-peak energy and support your Net Zero commitments.

  1. Ongoing Compliance & Reporting Support

As MHHS introduces new reporting and data obligations, eyebright can manage compliance, ensuring your business meets industry standards while minimising administrative burden.

What Should You Do Now?

  1. Check your metering setup – confirm your meters are smart or advanced.
  2. Review your energy contracts – assess exposure to peak pricing and flexibility options.
  3. Engage with advisors like eyebright – develop a tailored strategy before the 2025 migration begins.
  4. Educate your team – ensure decision-makers understand the operational and cost impacts.

Conclusion

Market-Wide Half-Hourly Settlement represents a fundamental shift in the UK’s electricity market, from estimation to precision, from static pricing to dynamic flexibility. The benefits are significant: fairer costs, more innovation, and a crucial step toward a smarter, low-carbon energy future.

For businesses, however, success will depend on preparation. With eyebright’s expertise in energy procurement, data analytics, and compliance, you can stay ahead of change, transforming MHHS from a regulatory requirement into a competitive advantage.