What is half hourly settlement?
Half hourly settlement is a change to how your supplier gets paid for the electricity you use, not a new charge on your bill. Instead of your supplier estimating your usage or reading it once a day, your actual electricity use gets recorded in 48 half hourly slots every day and settled against the wholesale market at that level of detail.
It sounds technical because it is technical. But the point for you, the household paying the bill, is simple. Hal hourly settlement means suppliers pay for exactly what people like you actually use, when you use it, rather than a rough average smoothed across the day.
Why is half hourly settlement happening now?
Ofgem and the industry body Elexon have been rolling out half hourly settlement across the whole electricity market, migrating meters in stages rather than flicking one big switch. The target is for all domestic electricity customers to be moved onto half hourly settlement by October 2026, with the system fully bedded in by May 2027.
Doing nothing about this one is fine, by the way. Unlike a lot of the energy admin Switcheroo usually nags you about, half hourly settlement is not a switch you need to organise yourself. It happens in the background, on your supplier’s timetable, not yours.
Do I need to do anything about half hourly settlement?
No. If you have a smart meter that is sending readings automatically, you’re already most of the way there, and your supplier will migrate you to half hourly settlement without you lifting a finger. You might get a letter or an email from them mentioning it. You can safely file that under “not urgent”.
There’s no application, no new contract to sign and no meter to book in for this specific change. If a smart meter is already fitted and working, half hourly settlement is largely happening to the plumbing behind your account, not to anything you’ll need to click or approve.
What happens if I don’t have a smart meter?
If you’re still on a traditional meter, half hourly settlement can still apply to your account, just using an estimated consumption profile based on your property type and past usage rather than real half hourly readings. It’s less precise, and it’s one more reason a smart meter tends to work in your favour rather than against you.
Roo would say this is the closest thing to a genuinely free upgrade in the energy world: book a smart meter install through your supplier, and you go from being estimated for to being measured properly.
Will half hourly settlement change my energy bill?
Not on its own, and not overnight. Half hourly settlement changes how your supplier is charged behind the scenes, not the headline rate on your current tariff. Nobody should see a bill jump purely because their meter got migrated.
Where it matters more is further down the line. Once suppliers can see true half hourly usage across their whole customer base, it becomes easier for them to price tariffs that reward using electricity outside the peak evening rush, roughly 4pm to 7pm, when wholesale prices are typically highest.
That’s already visible in the small but growing number of time of use and dynamic tariffs on the market. Half hourly settlement is the infrastructure those tariffs need to work properly and fairly at scale.
What half hourly settlement means if you’re thinking about switching
Half hourly settlement itself is not a reason to switch supplier. But it is worth knowing about if you’re weighing up a time of use or dynamic tariff, because those deals only make sense once your usage is actually visible in half hour detail.
If most of your electricity use already happens in the evening, cooking, telly, charging everything at once, a flat rate fixed tariff is probably still your simplest, safest bet. If you can shift some of it, an EV charging overnight, a dishwasher on a timer, half hourly settlement is what makes a cheaper off peak rate possible in the first place.
Half hourly settlement at a glance
- What it is: usage recorded and settled in 48 half hour slots a day, instead of one daily estimate.
- Deadline: all domestic customers migrated by October 2026, fully live by May 2027.
- Action needed: none, if you already have a working smart meter.
- No smart meter: you’re still covered, just on an estimated profile until one’s fitted.
- Bill impact: no automatic change to your rate, but it opens the door to time of use tariffs.
Frequently asked questions about half hourly settlement
- Is half hourly settlement the same as a smart meter?
- No. A smart meter is the device in your home. Half hourly settlement is the industry process that uses the data from meters like it to settle the market. You can have one without fully benefiting from the other, though in practice they go hand in hand.
- Will half hourly settlement affect my direct debit?
- Not because of the settlement change itself. Your direct debit is set by your supplier based on your estimated annual usage and current tariff rate, and that calculation doesn’t change just because the industry is now settling your usage in half hour slots.
- Can I opt out of half hourly settlement?
- Not really, no. It’s a market wide reform for domestic electricity customers rather than an optional product, so there’s no opt out to request from your supplier. Choosing to stay on a traditional meter simply means you’re settled on an estimated profile instead of real readings.
- Does half hourly settlement apply to gas too?
- No, this reform is specific to electricity. Gas settlement continues to work on its existing, separate arrangements.
- Will I be told when my account has moved to half hourly settlement?
- Most suppliers are expected to notify customers around the point of migration, though the format varies by supplier. If you want to check sooner, your supplier’s customer service team can tell you where your account sits in their rollout.
Half hourly settlement won’t show up as a line on your bill and it isn’t something you need to chase. But if you’ve been eyeing up a smarter, usage based tariff, this is the quiet bit of plumbing that makes those deals possible. Worth understanding, not worth losing sleep over.
