Economy 7 explained
Guide · updated 2026-08-23
Economy 7 gives seven cheap hours overnight and a dearer rate for the other seventeen. It is decades older than smart tariffs and still on millions of meters.
Two registers, not one
An Economy 7 meter has two counters. A timeswitch moves consumption from the day register to the night register for seven hours, and back again. Your bill shows both, with a different unit rate against each — but only one standing charge.
The day rate is higher than a single-rate tariff's, sometimes considerably. That is the trade: cheap nights are paid for by expensive days.
When are the cheap hours?
There is no national answer. The window depends on your meter and your region, and typically starts somewhere between 23:00 and 00:30. Some meters shift with British Summer Time; some do not. Some regions historically split the seven hours into two blocks.
Do not trust a figure from a forum. Check the meter: note both register readings late one evening, run a known load overnight, and read them again in the morning. Whichever register moved tells you what the meter thinks. Getting this wrong means heating your storage heaters at the day rate all winter, which is the single most expensive mistake available on this tariff.
Does it still pay?
Roughly, you need about 40% or more of your electricity in the night window for Economy 7 to beat a single-rate tariff. In practice that means storage heating, an electric hot-water cylinder, or overnight EV charging. A household that simply runs the dishwasher late will not get close.
Work out your own split from your bill: night kWh divided by total kWh. If it is under a third, you are probably losing money.
What to move to
With a smart meter you can usually beat Economy 7 outright. Snug is the closest modern equivalent for storage heating, Cosy suits heat pumps with its three cheap blocks a day, Go suits EV charging, and Agile suits anyone who can chase the cheapest half hours — including the negative ones.
One caution: moving off Economy 7 usually means a meter change, and storage heaters wired to a separate off-peak circuit may need rewiring to work on a normal supply. Ask before you switch, not after.
Common questions
What time does Economy 7 start and end?
It varies by meter and region, usually starting between 23:00 and 00:30 and lasting seven hours. Some meters follow British Summer Time and some stay on GMT year round.
Is Economy 7 worth it?
It pays when roughly 40% or more of your electricity is used overnight, which in practice means storage heating, an electric hot water cylinder or EV charging. Below that the higher day rate costs more than the night rate saves.
Can I switch from Economy 7 to a normal tariff?
Yes, though it usually needs a meter exchange, and storage heaters wired to a separate off-peak circuit may need rewiring first.
See it on your own numbers. halfhourly.uk shows live half-hourly prices for every GB region for free, and if you connect an Octopus account it prices your own smart-meter readings against every tariff.