Half hourly settlement is here: what it means for your business and what to do about it
The way every electricity meter in Great Britain is measured and billed is being overhauled. It is called Market-wide Half Hourly Settlement, and it affects every business with an electricity supply. The changes are already live, most businesses will be migrated by May 2027, and those who prepare now stand to benefit. Here is what you need to know, in plain terms.
What is changing and why does it matter?
Put simply, the energy regulator Ofgem is changing how electricity usage is measured, recorded, and financially settled across the whole of Great Britain. Instead of relying on estimated readings or infrequent manual meter checks, the new system will use actual consumption data taken every 30 minutes.
This is called Market-wide Half Hourly Settlement. It has been in development for several years and the systems went live in September 2025. The migration of individual meters started in October 2025 and will continue through to May 2027.
Why does this matter to your business? Because it changes how your electricity costs are calculated. Under the old system, most smaller and mid-sized business meters were settled using estimated profiles that assumed when you were using energy. Under the new system, your actual usage, measured every half hour, will determine what you pay. That is a fundamental shift, and it creates both risks and opportunities depending on how you respond.
Ofgem estimates this reform will save consumers between £1.6 billion and £4.5 billion by 2045 through a more accurate and efficient energy system. But those savings depend on businesses engaging with the change, not simply letting it happen.
When is it happening?
The programme is already underway. Here are the dates that matter:
The bottom line: your meters will be migrated. This is not optional. The only question is whether your business is ready to make the most of it.
Answering the questions you are actually asking
Will my bills go up?
Not necessarily, and for many businesses they could go down. Under the old system, if your business used most of its electricity outside of peak hours, you were likely being overcharged because the estimated profiles assumed a typical usage pattern that may not have matched yours. Half-hourly settlement means you pay for what you actually use, when you actually use it. If your consumption pattern is favourable, your costs could fall.
However, the reverse is also true. Businesses that concentrate their electricity use during expensive peak periods may find their costs increase once settlement is based on actual data rather than averages. The key point is that you will finally have visibility of this, which means you can do something about it.
There may also be modest additional charges for the new metering and data services that the reform requires. These are typically small relative to your overall energy spend, and in many cases will already be reflected in your standing charges.
Do I need to spend money on new meters?
You are not legally required to replace your existing meters. The migration will happen regardless of what meter type you have. However, businesses that still have older traditional meters (the kind that require someone to physically come and read them) will miss out on the main benefits. Their consumption will be estimated using modelled profiles rather than measured with real data.
If you want the accuracy, insight, and cost-saving potential that half-hourly settlement is designed to deliver, upgrading to a smart meter or an automated meter is the single most impactful step you can take. The cost of an upgrade is typically modest and often recoverable through better energy management within months.
What happens if I just ignore this?
Your supplier will migrate your meters regardless, and if you have not made active choices, they will appoint service providers on your behalf. You will still be compliant. But you will likely end up with default service arrangements that may not be the best fit for your business, you will miss the opportunity to choose providers who offer better value or capability, and you will not be positioned to use your new half-hourly data to reduce costs or improve your energy strategy.
In short, ignoring it will not cause a crisis, but it means leaving money and competitive advantage on the table.
What is changing behind the scenes
You do not need to understand every technical detail, but it helps to know the broad strokes so you can have informed conversations with your energy supplier and service providers.
Your meters will be reclassified
The old way of categorising meters as either half-hourly or non-half-hourly is being replaced. Meters will now be grouped by technology type: advanced meters (including automated reading devices), smart meters, and unmetered supplies. If your business has a mix of meter types across different sites, they may fall into different categories with different service requirements.
The companies that look after your meters and data are changing
The traditional roles that manage your metering hardware and energy data are being restructured and renamed. The important thing to know is that under the new system, you have the right to choose your own metering and data service providers. These are now offered as separate contracts rather than being automatically bundled into your energy supply agreement.
This is actually a significant improvement. It means you can shop around, compare service levels, and appoint providers based on what is best for your business. If you do not make an active choice, your supplier will appoint someone for you, and that default may not be the most competitive or capable option available.
Some of the reference numbers on your invoices will look different
Certain technical codes on your electricity bills and meter point references are being updated to reflect the new system. If your business processes invoices manually, you are unlikely to notice. But if you use automated systems or electronic invoice processing, it is worth checking that your software can handle the new formats.
Financial reconciliation will happen much faster
The current system takes up to 14 months to fully reconcile what a supplier purchased against what customers actually used. The new system will do this in four months. For businesses, that means fewer surprises from backdated adjustments and a clearer, more current picture of your energy costs.
How to turn this into a commercial advantage
Most of the guidance around this reform tells businesses to relax and let their supplier handle everything. That is fine if compliance is all you care about. But if you want to reduce energy costs, strengthen your sustainability credentials, or simply run a tighter operation, this reform creates real opportunities:
- See exactly where your energy goes. For the first time, every site in your portfolio will be measured on the same half-hourly basis. That gives you a genuine like-for-like comparison across locations, making it far easier to spot waste, benchmark performance, and hold sites to account.
- Pay less by using energy smarter. Half-hourly data enables tariffs that reflect the real cost of electricity at different times of day. If your business can shift non-essential energy use away from peak periods, or store energy during cheaper windows, you stand to make meaningful savings.
- Earn revenue from flexibility. Accurate half-hourly data is the foundation for participating in demand flexibility programmes. As the electricity grid depends more on renewable generation, businesses that can adjust their demand in response to grid signals can earn income for doing so.
- Strengthen your carbon reporting. Granular consumption data makes it significantly easier to track and report your energy-related emissions with precision. For businesses facing mandatory climate disclosures or pursuing sustainability targets, this is a practical step forward.
- Make better procurement decisions. Half-hourly data gives you a far more accurate picture of your demand profile, enabling sharper energy procurement strategies and reducing the risk of over-contracting or under-contracting.
Five practical steps to take now
- Find out what meters you have. Ask your energy supplier or facilities team to provide a list of all your electricity meters and their types. If you still have older traditional meters, explore upgrading to smart or automated meters so you can access the full benefits of half-hourly data.
- Choose your own metering and data service providers. Do not leave this to your supplier by default. You have the right to appoint independent providers who may offer better service, better pricing, or deeper expertise. This is one of the most important decisions you can make during this transition.
- Check your invoicing systems. If your business uses automated invoice processing or any system that reads meter reference numbers, verify that it can handle the updated codes and formats. A quick check now avoids disruption later.
- Get the right tools to use your data. Half-hourly data is only valuable if you can analyse it. An energy management platform that gives you clear visibility of consumption patterns, costs, and carbon performance across your whole portfolio turns raw numbers into decisions that save money.
- Talk to your energy supplier. Ask them when your meters will be migrated, what their qualification status is, and whether you should expect any changes to your bills or contracts. Do not wait to be told. Ask now.
How SMS can help
SMS is one of the UK’s leading independent energy infrastructure providers. We manage over four million meter assets and work with businesses, energy suppliers, and public sector organisations across every part of the energy value chain. Crucially, we are independent. We do not supply energy, which means our advice is always in your interest, not tied to a supply contract.
We operate across every area that this reform touches:
- Metering. We install, maintain, and operate smart meters and automated meters for businesses across the UK. We can audit your existing metering estate, recommend upgrades where they will add value, and manage the transition to the new service arrangements.
- Data and settlement. We provide the data collection and processing services that half-hourly settlement requires. We are accredited to provide the new metering and data service roles, meaning you can appoint SMS as your independent provider rather than accepting your supplier’s default.
- Energy analytics. Our energy management platform, SmartVision, gives you clear, portfolio-wide visibility of your half-hourly consumption data, helping you identify savings, track carbon performance, and make better energy decisions.
- Energy strategy. Our energy services team can help you develop a net zero roadmap, optimise your energy procurement, explore renewable energy and battery storage, and participate in demand flexibility programmes.
Whether you need a full metering audit and upgrade programme, an independent data service provider for the transition, or simply a clearer view of your energy performance, we can help.
Do not let this change happen to you. Make it work for you.
This is the most significant structural change to the electricity market in a generation. It is not optional, and the timeline is fixed. But within that framework, businesses have real choices to make about their metering technology, their service providers, and how they use the wealth of data that half-hourly settlement will generate.
The businesses that treat this as a strategic opportunity rather than an administrative inconvenience will be the ones that emerge with lower energy costs, stronger sustainability credentials, and a more resilient energy strategy.
The window to prepare is now.
