Half hourly settlement: What it means for your energy
| OVO
Your energy account is about to get smarter. Half hourly settlement is rolling out across the UK for all energy suppliers, including OVO. If you've got a smart meter, it will mean more accurate bills and a greener grid.
Here's everything you need to know about half hourly settlement and how it works with your smart meter.
What is half hourly settlement?
Market Wide Half Hourly Settlement (also called half hour settlement or MHHS) is a new way of tracking how and when we all use electricity. It’s being introduced by Ofgem to create a more efficient grid, helping us all use more renewable energy.
If you opt in to MHHS, instead of energy companies estimating your usage based on monthly readings, your smart meter shares your actual electricity use every 30 minutes. This is done automatically, so there’s nothing you need to do.
Think of it like the difference between guessing how far you've driven this month versus your car telling you the exact mileage.
More accurate data means more accurate bills for you, and a smarter energy system for everyone as we’ll understand exactly what energy is being used at any point of time.
Why the change to half hourly settlement?
Right now, energy suppliers buy electricity based on rough estimates of when their customers will use it. But with half hourly settlement, we can see exactly when you're using power and buy the right amount of energy at the right time.
This matters because electricity costs change every 30 minutes. When demand is low and the sun's shining or the wind's blowing, renewable energy is cheaper and cleaner. When everyone's cooking dinner, and demand spikes, we have to rely on more expensive, carbon-heavy power sources.
With half hour settlement data from your smart meter, we can buy more of your energy from renewable sources and less from fossil fuels. That's better for the planet and could help keep costs down for everyone.
How does half hourly settlement work with smart meters?
Your smart meter is the key to making half hourly settlement happen. Once you have opted in to half hourly settlement, your meter automatically sends half hourly readings to us, showing when you use electricity throughout the day.
The great thing about smart meters is they make half hour settlement completely automatic. Once you have consented to half hourly settlement, you don't need to do anything - your smart meter handles it all in the background.
Don't have a smart meter yet? Now's a great time to get one. They're free to install and give you more control over your energy use. You can see exactly what you're using in real-time, spot which appliances are costing you the most, and find ways to save.
What's in it for you?
Half hourly settlement isn't just good for the grid. It opens up new possibilities for you too.
More accurate bills - No more bill shocks from estimated readings. Your bills will reflect what you've actually used, giving you a clearer picture of your energy costs.
Better tariffs - As half hourly settlement becomes standard, more time of use tariffs that reward you for using energy at greener, cheaper times of day will become available. Think EV charging overnight when wind power is abundant, or running your washing machine when the grid is powered by renewable energy.
Help the planet - By shifting when you use power (even just a little), you're helping balance the grid and supporting renewable energy. Small changes, big impact.
Energy insights - With your smart meter and half hourly settlement data, you'll get a much better understanding of your energy habits. That means more opportunities to save money and reduce your carbon footprint.
What about your privacy?
We know your data is personal and we rely on you to opt in to half hourly settlement. We'll always keep your smart meter data safe and only use it for the things we've told you about. Your half hourly readings help us buy the right energy and bill you accurately, but we won't use them for anything else without asking you first.
When does half hourly settlement start?
Half hourly settlement is rolling out across 2025, 2026 and 2027. If you've got a smart meter, we'll be in touch to let you know what's happening and when. In most cases, the switch to half hour settlement will happen automatically and you won't need to do a thing.
The MHHS programme is a major transformation for the energy industry, but for you as a customer, it should be seamless – especially if you already have a smart meter installed.
How do I opt in to half hourly settlement?
You may already have chosen to opt in to MHHS when you last moved energy supply, or due to your supply choices, such as adding Charge Anytime, our tariff add-on for EV charging.
If you export energy back to the grid, your smart meter will automatically send half hourly readings to make sure you get paid accurately for the renewable energy you export.
If not, you can choose how often your smart meter readings are sent to us by heading to your account profile, either online or in the app.
If you don’t already have a smart meter, OVO installs them for our customers for free. Find out more about the process.
The bigger picture
Half hourly settlement is part of a massive transformation in how we use energy. As more homes get solar panels, batteries, heat pumps, and EV chargers, the electricity grid needs to get smarter to keep up.
Your smart meter and the half hourly settlement data it shares help make that possible. Together, we're building an energy system that's cleaner, fairer, and more flexible for everyone. With more renewable energy sources coming online, half hour settlement helps us make the most of green power when it's available.
Ready to get started with half hourly settlement?
If you don't have a smart meter yet, getting one is simple and free. It's the first step to unlocking more accurate bills, greener energy, and more control over your home. Your smart meter makes half hourly settlement work automatically, so you can benefit from more accurate billing and help support renewable energy without any extra effort. Get a smart meter.