Economy 7 Tariffs: How They Work and When They Save Money

Understanding Economy 7 tariffs

An Economy 7 tariff charges one price during seven off-peak hours and another, normally higher, price at other times. Ofgem says the off-peak period is often overnight, but its timing can vary by location and supplier.

The arrangement is most useful when a large part of the home’s electricity can be used or stored safely during the cheaper period. Storage heaters, a hot-water cylinder and scheduled EV charging can all change the calculation. Ordinary daytime use still lands on the peak rate.

The decision is therefore personal: compare a current Economy 7 quote with a current single-rate quote, use a full year of day and night readings where possible, and include both standing charges. The calculator on this page does that arithmetic without assuming a tariff or a switching time.^[1]

How dual-register meters and billing work

Economy 7 needs a meter that records peak and off-peak consumption separately. This may be a traditional two-rate meter or a smart meter configured for more than one rate. Displays vary by model, so labels such as Rate 1 and Rate 2 do not by themselves tell you which register is day or night. Check the bill or ask the supplier if you are unsure.

A bill on Economy 7 should show two electricity unit rates and the consumption charged at each, plus a daily standing charge. Ofgem states that the peak and off-peak rates on a multi-rate tariff together cannot exceed the applicable price cap. The actual pair still varies by region, supplier, meter and payment method.

A home can retain two registers while being billed at one rate. In that case the supplier may total the readings for billing, depending on its systems and the meter. Confirm the account tariff rather than inferring it from the meter hardware.

The distinction also matters in local energy-use data: published multi-register meter counts describe a physical meter arrangement, not the number of households currently paying Economy 7 prices.

When are the seven cheaper hours?

Midnight to 7am is a common description, but it is not a promise for every Economy 7 meter. Ofgem says the period may vary by location and supplier. Ask for the exact times that apply to the meter before setting heating, hot water or charging schedules.

Clock changes need a separate check. Some arrangements remain on Greenwich Mean Time while others adjust to British Summer Time. Do not shift a timer by an hour because a generic guide says to; confirm how the meter behaves with the supplier and check which register advances during the expected window.

Calculating your break-even point

Savings occur only when the discount on off-peak electricity outweighs the premium on peak electricity and any standing-charge difference. A percentage copied from another Economy 7 tariff cannot answer that question because all four prices can vary.

Use annual meter readings if you have them. The relevant share is the electricity recorded on the night register divided by the total across both registers. It is not seven hours divided by twenty-four, because consumption is not spread evenly through the day.

Heating, appliances, and safety risks

Storage heaters and hot-water cylinders are natural Economy 7 loads because they store heat produced during the off-peak period. EV charging can also be scheduled while the car is parked. Check that controls follow the meter’s real switching times rather than a generic overnight window.

A gas-heated home with no car, battery or other substantial overnight load may have little electricity it can sensibly move. That does not make Economy 7 automatically unsuitable, but it raises the off-peak share the household must create from smaller loads.

Do not use delay timers to run a washing machine, tumble dryer or dishwasher overnight and unattended. London Fire Brigade’s bedtime guidance says these appliances should not be left on in that situation. Follow the appliance manufacturer’s safety instructions as well.^[1]

Economy 7 versus modern smart tariffs

As one form of time-of-use pricing, Economy 7 now sits beside smart tariffs that can use fixed daily bands, a price set for each day or half-hourly prices. Those structures answer different household needs and should not be treated as one category with one winner.

Its predictable seven-hour schedule can work with storage heating and simple timers. The unit rates themselves can still change when the tariff terms allow, including when a capped variable tariff is updated.

A smart tariff may reward more flexible scheduling, but it may also require half-hourly readings, compatible equipment or attention to changing prices. If you can download your half-hourly data, the smart-meter tariff replay compares the measured pattern in your browser instead of assuming when you use electricity.

Some older multi-rate arrangements use the Radio Teleswitch Service. Ofgem says its signal is being switched off in phases and an affected meter may no longer switch heating, hot water or rates correctly. Contact the supplier if the meter may use RTS; it must arrange a suitable replacement without disrupting the service.^[1]

Switching tariffs and comparing live rates

If Economy 7 no longer fits, ask the current or prospective supplier whether it can bill the existing meter on a standard single-rate tariff. Citizens Advice recommends checking that the new tariff will work with the meter before switching. A meter exchange or smart-meter configuration change may be needed in some cases.

When a supplier supports single-rate billing on a two-register meter, it can use both readings to calculate total consumption. Confirm how readings should be submitted and keep a record of both at the changeover.

The bill benchmark calculator keeps single-rate and multi-register consumption assumptions separate, which helps when you are sense-checking annual use before comparing quotes.

A quoted day and night rate does not establish the switching schedule. Confirm the seven off-peak hours separately, especially after a meter replacement or smart-meter reconfiguration.

For Octopus, the Flexible Octopus review shows the currently available regional day and night rates when the supplier feed provides them. Use your postcode or electricity region and still confirm the actual switching times for your meter.

Final verdict