MHHS is a major regulatory initiative led by Ofgem (the UK’s energy regulator) to modernise the way electricity usage is measured and settled across the country. Instead of settling energy usage based on broad estimates or profiles, MHHS will require all electricity consumption to be settled using actual or estimated half-hourly data.

For large industrial and commercial sites, half-hourly settlements are already standard. MHHS will extend this practice across the board, covering businesses that currently rely on traditional non-half-hourly billing. This shift is designed to reflect true consumption patterns and to promote more efficient use of energy.

P432 is a precursor requirement to support a smooth roll-out for Market-Wide Half-Hourly Settlement. Click here for more information about P432.

• Accurate Consumption Data: By capturing electricity use in 30-minute intervals, suppliers, network operators, and customers can gain a clearer picture of when and how much energy is consumed. This helps reduce reliance on estimates and opens the door to more precise forecasting.
• Encouraging Flexible Energy Use: As the UK strives for a greener grid and a zero-carbon electricity system by the mid-2030s, half-hourly data can support innovative solutions such as time-of-use tariffs, battery storage, and electric vehicle charging incentives. These offerings reward you for shifting your energy usage to off-peak periods, when electricity is often cheaper and greener.
• Potential Cost Savings: With better insight into peak demand and consumption patterns, you can adjust usage to reduce costs. Ofgem predicts MHHS could bring significant net benefits to consumers by 2045 through more efficient settlements and flexible tariffs.
• Driving Net Zero Goals: An energy system that fully utilises renewable generation sources depends on accurate, timely data to balance supply and demand. MHHS supports the continued growth of wind and solar power and helps reduce the need for carbon-intensive backup generation.

1. Behind-the-Scenes Changes: For many businesses, most of the MHHS transition happens behind the scenes. We’ll be updating our internal processes and systems to handle half-hourly data in line with the new requirements. You may not notice any immediate changes to your day-to-day operations.

2. Billing and Tariffs: Once MHHS is in place, suppliers can develop tariffs that better reflect real-time energy costs. These time-of-use or dynamic tariffs could help you save money if you can shift some of your consumption away from peak periods. If you have a smart or Automatic Meter Reading (AMR) meter, your bills will be more directly tied to your half-hourly usage data.

3. Metering Upgrades: If you do not already have a smart meter or an AMR meter, you may miss out on some of the cost-saving and sustainability benefits. Under MHHS, sites without half-hourly capable meters will have their consumption estimated using load-shaping techniques. This approach won’t be as accurate as real half-hourly data and could limit access to the best tariffs. We recommend upgrading to a smart or AMR meter as soon as possible to fully unlock the potential benefits of MHHS, such as accessing new tariffs and gaining detailed insight into your energy usage.

4. Potential Changes to Supply Details: Your Meter Point Administration Number (MPAN) classification could change under the new system. While this shouldn’t disrupt your energy supply, it may result in updated terminology on bills or quotes.

• Fairer Pricing: Under MHHS, your energy costs can more accurately reflect the times you use electricity the most. By moving away from estimated profiles and relying on half-hourly data, you’ll benefit from pricing structures that better match your actual consumption habits.
• Improved Billing Transparency: With detailed 30-minute data, your bills will show a clearer breakdown of your energy usage. This enhanced transparency makes it easier to understand where and when you’re consuming the most power.
• Incentives for Energy Efficiency: Real-time or near real-time insights into consumption can reveal opportunities to optimise energy use. Suppliers may introduce new incentives or rewards for off-peak usage, making your efforts to be more energy efficient both environmentally and financially beneficial.
• Increased Flexibility and Control: Half-hourly settlement paves the way for innovative products and services, such as time-of-use tariffs or demand-side management programs. By adjusting your consumption patterns to align with lower-cost periods, you gain more control over both your energy spend and carbon footprint.
• Potential for Enhanced Services and Products: With richer data at hand, suppliers can offer tailored solutions to meet your specific needs—ranging from bespoke pricing plans to advanced monitoring tools. These new offerings can help you stay competitive and future-proof your operations in an evolving energy market.
• Potential for Lower Bills: By taking advantage of off-peak rates and streamlining your consumption, you may see real financial savings over time. This not only helps your bottom line but also contributes to a more sustainable, lower-carbon energy system overall.

The MHHS programme rolls out in phases, with several milestones affecting all UK electricity suppliers:

• Now to mid-2026: Suppliers, metering agents and data providers are preparing for “qualification.” During this time, we are updating our systems to process half-hourly data for all customers.
• From September 2025: Central industry systems supporting MHHS go live. Suppliers who have qualified can start migrating customers’ meters to the new settlement arrangements.
• Late-2025 to mid-2027: Migration continues across the industry. Depending on your supplier’s progress, you might see small changes on your bills-such as updated meter segment classifications or different terminology.
• By May 2027: The bulk of all electricity meters across the market should have been migrated to half-hourly settlement. At this point, most of the behind-the-scenes work is done.
• Final Enhancements in 2027: The transition continues through mid to late 2027 to fine-tune the settlement timetable and final processes.

1. Check Your Meter Type: If you already have a smart or AMR meter, you’re in a good position to benefit from half-hourly settlement. If you still use a traditional meter, consider upgrading as soon as possible. For more information, click here.

2. Review Potential Tariff Opportunities: Keep an eye out for any new tariffs or products we may introduce that could help your business save money by optimising energy use.

3. Stay Informed: We’ll keep you updated on any changes that might affect your bills or supply. Follow us on Linked-in for further monthly updates and progress.

1. Meter Upgrades: We can help you switch to a smart or AMR meter, ensuring your sites are MHHS-ready and that you can make the most of future energy products and services. Click here to get started.
2. Guidance & Support: Our experts are on hand to explain how MHHS changes might affect your specific business. We’ll provide clear communication about any adjustments to your billing or contract.
3. Innovative Solutions: As MHHS rolls out, we’ll look to offer flexible tariffs and products that reward more efficient energy usage-helping you reduce costs and lower your carbon footprint.

United Gas & Power remains committed to providing transparent, straightforward energy guidance to our business customers. As MHHS rolls out, we’ll ensure you’re fully informed at every stage, helping you harness this opportunity to innovate, save, and work towards a greener future.