Time-of-use electricity tariffs UK explained

What does 'time-of-use' actually mean?

A standard flat-rate electricity tariff charges the same price per kWh whether you switch the kettle on at 3am or 6pm. A time-of-use tariff splits the day into bands — usually a cheap overnight 'off-peak' window and a more expensive 'peak' period — so the price you pay depends entirely on the clock.

The logic is simple: electricity demand isn't flat across the day, but supply increasingly is (particularly from wind, which doesn't care what time it is). Time-of-use tariffs pass some of that variability on to households, rewarding people who can shift consumption into low-demand windows.

For most homes this means moving big loads — washing machines, tumble dryers, EV charging, and increasingly battery charging — into the cheap overnight band, and drawing down stored or reduced usage during the expensive peak.

Why time-of-use tariffs exist in 2026

Two things have made time-of-use pricing mainstream rather than a niche Economy 7 curiosity: smart meter rollout and the growth of intermittent renewable generation on the grid. Smart meters give suppliers half-hourly consumption data, which is what makes granular pricing possible at all — without one, none of these tariffs work.

On the supply side, a grid with a lot of wind and solar needs to nudge demand around to match generation, rather than the old model of generation following demand. Cheap overnight rates encourage EV charging and battery charging when there's often surplus wind power and little demand; peak pricing in the early evening reflects the genuine cost and carbon intensity of meeting demand when renewables are low and everyone gets home and switches things on.

Rates change — always check the supplier's current pricing. Correct as of July 2026.

This is also why the number of tariff types has multiplied. What used to be a binary choice between flat rate and Economy 7 is now a spectrum running from fixed two-rate deals through to fully dynamic half-hourly pricing that changes every day.

The main tariff types, in depth

Standard flat-rate tariffs charge one price around the clock. They're simple and predictable but offer no reward for flexibility — if your household usage is fairly evenly spread through the day, or you can't shift any of it, a flat rate may genuinely be the least hassle option.

Economy 7 is the original time-of-use tariff, giving a roughly 7-hour cheap overnight window (commonly somewhere in the small hours) with a higher rate for the remaining 17 hours. Economy 10 extends the cheap allowance to around 10 hours, often split across a night block plus a short afternoon dip, suiting homes with daytime occupants such as retirees. See our dedicated pages on Economy 7 and whether electricity is cheaper at night for the detail.

EV and overnight smart tariffs (like Intelligent Octopus Go and similar EV-focused deals) offer a shorter, deeper discount window — typically 5-6 hours overnight — pitched at EV owners but equally useful for battery owners who can charge fully within that window. Our EV tariff comparison covers how these stack up against each other.

Dynamic time-of-use tariffs such as Agile-style or Cosy-style products change pricing more frequently, sometimes half-hourly, tracking wholesale market prices. These can produce very cheap windows and very expensive peaks — appealing to engaged households willing to actively respond, less so if you want to 'set and forget'. Export-focused tariffs like Flux pair time-of-use import pricing with an enhanced export rate structure, aimed squarely at households with a battery and/or solar who want to buy low and sell (or avoid buying) high.

How a home battery multiplies the saving

Without a battery, a time-of-use tariff only helps if you can physically move your usage — running the dishwasher at 1am, for example. In practice most households can shift some load but not the bulk of it: lighting, cooking, TV and general evening consumption happens when it happens.

A battery removes that constraint. It charges from the grid during the cheap off-peak window, then powers the house through the expensive peak period regardless of when you actually use appliances. You get the off-peak rate for effectively all your consumption, not just the bit you can reschedule.

As an illustrative example only: if a battery cycles 10 kWh a day, charging off-peak at roughly 10p/kWh and displacing peak-rate usage at roughly 28p/kWh, that's an 18p/kWh spread — around £1.80-£2.00 of saved cost per day, or somewhere in the region of £650-£700 a year, before accounting for battery cost, efficiency losses, or tariff and rate changes. This is a worked example to illustrate the mechanism, not a forecast for any specific household.

Rates change — always check the supplier's current pricing. Correct as of July 2026. Use our calculator to run the sums against your own usage and a current tariff rather than relying on illustrative figures.

Time-of-use tariff comparison

The table below summarises how the main tariff families compare on structure. Rates are EXAMPLE figures only, kept broadly consistent with typical 2026 market bands, and will not match any specific live tariff.

When switching to a time-of-use tariff is NOT a good idea

If your home doesn't have a smart meter and you have no near-term plan to get one, most modern time-of-use tariffs simply aren't available to you — so this is the first practical filter, not a preference.

If your usage pattern is genuinely flat — for example a household that's out most of the day and evening, with little scope to shift laundry or cooking, and no EV or battery — a time-of-use tariff can occasionally leave you worse off, because the peak rate applies to a larger share of your fairly average consumption while you gain little from the off-peak discount.

Similarly, some dynamic tariffs carry a small standing charge or rate premium relative to the cheapest flat deals in exchange for the flexibility on offer. If you're not going to actively use that flexibility — via a battery, EV, or habit change — you may be paying for optionality you don't use. It's worth checking British Gas PeakSave and Octopus tariff structures specifically, since standing charges and eligibility criteria vary supplier to supplier.

Checklist before you switch

Confirm you have a working smart meter sending half-hourly readings — not just a meter that looks smart but is stuck in a dumb mode, which happens more often than suppliers admit.

Map your actual usage pattern for a fortnight if you can, ideally against existing smart meter data, so you know how much load is genuinely shiftable versus fixed.

Decide whether you're switching to change behaviour (moving laundry and charging to off-peak hours) or to support hardware (an EV, a battery, or both) that can absorb the off-peak window automatically — the two goals point to different tariff types.

Check the exit terms and standing charge of any new tariff, and read the specific supplier page for the type you're considering — our guides to Octopus tariffs explained and best SEG export rates cover two of the most commonly bundled add-ons.