Analysis
Market-wid Half-hourly Settlement (MHHS) – A Guide for UK Businesses
Understand What the Half-Hourly Energy Shift Means for Your Business
Part of our business electricity guides
If you’ve heard about MHHS and you are not quite sure what it means for your business, you are not alone. It is one of the biggest changes to UK business electricity settlement in decades, and it is worth understanding what is changing and what stays the same.
MHHS explained
This guide explains Market-wide Half-hourly Settlement in plain English so you can see how it could affect your business electricity contracts and the types of tariffs that may become more common.
Quick answers that people actually want to know
If you’re skimming, here’s the gist.
MHHS is a UK-wide change that settles electricity usage using half-hourly (30-minute) meter data, rather than broad estimates. It’s not optional either. It’s a mandatory market migration.
Most businesses will not need to do anything because your supplier handles the behind-the-scenes changes. Still, it’s worth understanding what it is, especially if you’re renewing soon.
Will it change your bills. The main aim is more accurate billing, and it also opens the door to new tariff options, including Time of Use pricing.
What is MHHS?
Market-wide Half-Hourly Settlement (MHHS) is a mandatory reform that changes how every business in the UK is billed for electricity.
Instead of estimated bills based on your business profile or occasional meter readings, MHHS means your electricity consumption is recorded every 30 minutes. Your supplier receives accurate data showing exactly when and how much electricity you’re using throughout each day.
This is a fundamental shift from the old system where suppliers had to guess your consumption patterns and buy energy based on estimates. Those estimates often meant suppliers were buying too much or too little energy, creating inefficiencies that ultimately affected pricing.
Why is this change happening?
The UK energy grid is transforming to support the country’s Net Zero targets, and the old billing system simply wasn’t built for that future.
Here’s the problem the old system created. Renewable energy sources like wind and solar are brilliant for the environment, but they’re unpredictable. The grid needs accurate, real-time data to balance supply and demand when renewable generation fluctuates.
With half-hourly data from every business, grid operators can predict and manage demand far more effectively. This makes it easier to integrate renewable sources and reduce reliance on fossil fuel backup generation.
The MHHS programme estimates this reform will deliver between £1.6 billion and £4.5 billion in benefits to the UK economy over the next two decades. That’s not just environmental benefits, it’s real cost savings from a more efficient energy system.
What MHHS means for your business
The implications for your business are actually quite positive, even though change can feel uncertain.
Accurate billing without estimates. You’ll receive bills based on your actual consumption, recorded every 30 minutes. No more unpleasant surprises when your annual meter reading reveals you’ve been undercharged for months. You’ll see exactly what you’re using and when.
Better visibility of your energy patterns. The half-hourly data gives you a clear picture of your consumption throughout the day. You might discover that certain equipment is using more energy than expected, or that your peak usage times are costing you more than necessary.
Access to Time of Use tariffs. This is where the real opportunity lies. With accurate half-hourly data, suppliers can now offer tariffs where electricity costs different amounts depending on the time of day. We’ll explain more about this below.
Do you need a smart meter
A smart or advanced meter is needed for MHHS to work.
Smart meters automatically send half-hourly readings to your supplier, providing the accurate data that makes this whole system possible. Without a smart or advanced meter, there’s no way to capture consumption every 30 minutes.
The good news is that if you don’t already have one, your supplier will arrange installation as part of the MHHS rollout. This is a mandatory migration, so suppliers are managing the process to ensure every business is equipped.
If you’re considering switching your business electricity supplier, it’s worth checking whether they’ll install a smart meter as part of your new contract. Many suppliers are prioritising smart meter installations to comply with MHHS requirements.
When is this happening
The rollout is happening right now.
The mandatory migration began in October 2025, and suppliers must transition all meters by May 2027. Migration began in October 2025, so many businesses are already in the transition process, though timing varies depending on your supplier and location.
You don’t need to take any action. Your supplier is required to manage your transition behind the scenes. The change should be seamless, with no disruption to your electricity supply.
That said, it’s worth being proactive. Understanding MHHS now means you can start thinking about how to take advantage of the opportunities it brings, particularly when it comes to Time of Use tariffs.
What are Time of Use tariffs
Time of Use tariffs are pricing structures where electricity costs different amounts depending on when you use it.
Think of it like train tickets. Just as off-peak train travel is cheaper because there’s less demand, electricity during off-peak hours costs less because there’s lower demand on the grid.
Here’s how it works for your business. Peak times (typically weekday afternoons) cost more because demand is high. Off-peak times (evenings, weekends, overnight) cost less because fewer businesses are operating.
If you can shift some of your energy-intensive operations to off-peak hours, you could significantly reduce your electricity costs. For example, running equipment overnight, scheduling heating or cooling systems more strategically, or timing production processes around cheaper rate periods.
The half-hourly data from MHHS makes these tariffs possible because suppliers can accurately measure exactly when you’re consuming electricity.
How businesses can prepare
While the technical transition is automatic, there are practical steps you can take to benefit from MHHS.
Review your energy consumption patterns. Once you have access to half-hourly data, take time to understand when your business uses the most electricity. Look for patterns you might not have noticed before.
Consider operational flexibility. Ask yourself whether any processes could be shifted to off-peak times without disrupting your business. Even small changes can add up to meaningful savings.
Explore Time of Use tariffs. When it’s time to renew your business electricity contracts, ask suppliers about Time of Use options. Compare whether the potential savings justify any operational adjustments you’d need to make.
Keep your smart meter maintained. Your smart meter needs to work properly to provide accurate data. If you notice any issues, contact your supplier promptly.
The bigger picture for UK businesses
MHHS represents a shift towards a smarter, more flexible energy system that benefits businesses of all sizes.
For small businesses, it means fairer billing and the chance to reduce costs through smarter energy use. For larger operations with more flexibility to shift consumption, the savings potential is even greater.
The reform also supports the UK’s transition to renewable energy, which ultimately means a more stable and sustainable energy future. As renewable capacity grows, the grid becomes less reliant on expensive fossil fuel generation, which should help moderate long-term price increases.
We’re committed to helping you navigate these changes and find business energy solutions that work for your specific situation.
Making MHHS work for you
The important thing to remember is that MHHS is designed to give you more control, not less.
You’ll have clearer visibility of your energy costs, accurate billing without estimates, and access to tariff structures that reward flexible energy use. These are genuine opportunities to manage your electricity costs more effectively.
As the rollout continues through 2027, we’re here to help you understand your options and make informed decisions about your business electricity switch when the time comes.
If you’d like to discuss how MHHS affects your specific business or explore your options for competitive business electricity contracts, our team is ready to help. We’ll explain everything clearly, compare your options, and support you every step of the way.
Related guide: For the legal threshold and operational detail on the half-hourly meter itself (the kit that gets installed when your site goes onto half-hourly settlement), see our half-hourly electricity meter guide for UK businesses.
The body administering this change is Elexon, which runs the Balancing and Settlement Code that governs how electricity settlement works in Great Britain.
Your questions on this, answered in order
The questions businesses actually ask about this topic, in the order they tend to ask them. Each answer leads to the next; where we can help, there is a link.
What is market-wide half-hourly settlement and how will it affect my business?
Market-wide half-hourly settlement means electricity use is settled in 30-minute periods using smart or advanced meter data, rather than estimated profiles. Elexon is migrating meters with a target of completing by May 2027. For many businesses, nothing changes on day one, but it enables time-of-use tariffs that reward shifting usage away from peak periods.
Do I need a smart meter for half-hourly settlement?
To be settled on actual half-hourly data, your site needs a meter that can record and send half-hourly reads, such as a smart or advanced meter. Sites with older meters will continue to be settled using estimates until a meter is exchanged. Your supplier will usually contact you if a meter change is needed.
Will half-hourly settlement change my electricity price?
Your contracted rates won’t change just because settlement does. Over time, suppliers are expected to price more products on time-of-use, so costs could rise for heavy peak-time users and fall for those who can shift usage. Businesses that run equipment overnight or can schedule loads may find more suitable contracts as these products develop.
How can I reduce my peak-time electricity use?
Start by reviewing your half-hourly data to see when demand peaks, often weekday late afternoons and early evenings. Common steps include scheduling heating, refrigeration defrost or batch processes outside peak times, adding timers or controls, and using battery storage or on-site solar to cover daytime demand. Small changes can shift a surprising share of usage.
Would solar panels reduce my business electricity bill?
Solar can reduce the electricity you buy, especially if your business uses most of its power during daylight hours. The value depends on roof space, orientation, how much you use on site and export payments under the Smart Export Guarantee. Payback varies, so a feasibility assessment using your actual usage data gives a more reliable view than averages.
Can I get a solar survey for my business premises?
Clearsight Energy can arrange a commercial solar assessment. It looks at roof space and orientation, your half-hourly or annual usage, how much you’d use on site and what you might export. Having your electricity data to hand makes the feasibility figures far more realistic, so it’s worth sharing a year of usage when you ask. Get in touch →
How long does it take to install solar on a business roof?
Installation itself often takes days to a few weeks for a typical commercial roof, but the whole project takes longer. Survey, design, network operator approval and any structural checks come first, and larger systems needing G99 approval can wait months. Planning ahead of your next electricity renewal lets you size the contract around expected solar output.
Can I plan solar alongside my next electricity renewal?
Yes. Clearsight Energy can look at your solar plans and your electricity renewal together, so your contract volume reflects the grid power you’ll still need. That helps avoid volume tolerance issues later. Share your usage data, contract end date and site details, and we’ll explain the options and our fee. Get in touch →
Will I be able to see my half-hourly electricity data?
Yes, you can usually request your half-hourly data from your supplier or through their online portal, and some third-party tools can access it with your consent. This data shows exactly when you use electricity, which helps with tariff choice, spotting waste, checking bills and assessing solar or battery options.
Can my half-hourly data be used to check my bills?
Yes. Half-hourly data lets you compare actual usage with what’s been billed, spot estimated periods and confirm that day and night or time-band splits are correct. It also shows whether your capacity charges reflect your real peak demand. It’s one of the most reliable foundations for a bill check.
Can someone check my business electricity bill for errors?
Clearsight Energy offers bill validation, which compares your invoices against your contract rates, meter reads, standing and capacity charges, VAT and CCL treatment. Common findings include estimated reads, wrong VAT rates and charges carried over after a move. Send us recent bills and the contract and we’ll explain what we find and what can be raised with the supplier. Get in touch →
I have a half-hourly meter already, what changes for me?
Sites already on half-hourly settlement move to the new arrangements too, but the practical change is mostly behind the scenes, with new data services and processes. Your contract terms remain as agreed. It’s a good moment to check your agreed supply capacity and DUoS time bands, as these remain significant parts of a half-hourly bill.
Am I paying for more capacity than I use?
If your peak demand is well below your agreed supply capacity, you may be paying more each month than necessary. You can request a capacity reduction from your network operator, though increasing it again later may cost money and isn’t guaranteed. Review a full year of half-hourly data, including seasonal peaks, before asking for a change.
Can someone check my business electricity bill for errors?
Clearsight Energy offers bill validation, which compares your invoices against your contract rates, meter reads, standing and capacity charges, VAT and CCL treatment. Common findings include estimated reads, wrong VAT rates and charges carried over after a move. Send us recent bills and the contract and we’ll explain what we find and what can be raised with the supplier. Get in touch →