Time-of-Use Tariff

How we research

A time-of-use tariff is an electricity tariff where the price per unit changes at different times of day, so some times are cheaper than others.

Last updated: 19 October 2026

What it means

Smart Energy GB says off-peak times on these tariffs may offer lower prices depending on your supplier and tariff, and are often late evening, overnight or early morning. It says you need a smart meter to qualify. On a standard tariff, it says prices stay the same throughout the day, so there may be no cheaper time to run an appliance [1].

Why it matters when you buy

If you are on a time-of-use tariff, running a washing machine at off-peak times can lower the cost of each wash. If you are on a standard tariff, it will not [1]. Check your tariff’s own times before you change when you wash.

A worked example

A tariff charges 30p per kWh at standard times and 12p per kWh off-peak. If half of your washes are off-peak, the blended rate is (30 + 12) ÷ 2 = 21.0p per kWh. A wash that uses 0.5 kWh then costs 10.5p, compared with 15.0p if every wash were at 30p.

Illustrative scenario: figures are examples, not quotes, valuations or market prices.

Sources

  1. Best time to use the washing machine, Smart Energy GB, smartenergygb.org. Page last updated 17 August 2026. Checked 19 October 2026.