Guide · Prices and tariffs

Smart meters and time-of-use tariffs

A smart meter measures your electricity use and sends readings to your supplier. A time-of-use tariff is a separate choice that charges different prices at different times. You usually need the first to get the second, but having a smart meter does not change your tariff.

By energy.org.uk editorial team · Reviewed by energy.org.uk editorial team · Published and updated 2 October 2026

Who this is useful for

Households thinking about an electric car, home battery or heat pump.
People who can move some electricity use to cheaper times.
Anyone who wants accurate bills instead of estimated ones.

A smart meter is not a tariff

A smart meter records how much electricity you use, and when, and sends readings automatically. On its own, it does not reduce your use or your prices.
A time-of-use tariff has cheaper and more expensive periods. Citizens Advice says you usually need a smart meter to use one.

Who can get them

Smart meters in Great Britain: suppliers must offer them at no extra cost. Having one is your choice, not a legal requirement.
Northern Ireland: a separate smart meter programme applies. The Department for the Economy published its policy decision on the rollout on 29 April 2026, with NIE Networks responsible for installation. Check with your supplier what is available now.
Smart mode: the meter must be working in smart mode and sending readings. Ofgem notes that a meter not working in smart mode can stop you getting a time-of-use tariff.
Half-hourly readings: many time-of-use tariffs need these. Since 3 November 2022, new installations, supplier switches and new contracts default to half-hourly sharing. You can change this setting.
Tariff conditions: some time-of-use tariffs are only for electric-vehicle drivers, heat-pump owners, or homes with solar or a battery. Many mean switching supplier, and some need an app or a connected device. Check contract length and exit fees.

Types of time-of-use tariff

Citizens Advice describes three main types:

Static: cheap and expensive periods are at the same times every day.
Dynamic: prices change with the wholesale market, often every half hour.
Critical peak pricing: prices stay mostly the same, with occasional expensive “events” that you are told about in advance.

The peak-rate risk

The peak rate on a time-of-use tariff can be higher than a standard single rate. If you cannot move much of your use, you could pay more overall.
Some tariffs have an expensive late-afternoon or early-evening period, when many homes use the most electricity.
Dynamic prices can rise sharply at times.
Compare the standing charge too. A lower unit rate can come with a higher daily charge.

What to check first

How much electricity you use, and when. Your supplier’s app or online account can show this if your meter sends readings.
Which uses you could realistically move: EV charging, a battery, a hot-water cylinder, a dishwasher or laundry.
Every rate and time on the tariff, plus the standing charge, contract length and exit fee.
The eligibility conditions, before you apply.

Practical next steps

Ask your supplier for a smart meter, or check that your existing one is sending readings.
Choose half-hourly data sharing if you want to compare time-of-use tariffs accurately.
Use your own data to compare the tariff with what you pay now. Our tariff comparison calculator compares bills, and the home battery calculator shows the tariff change and a battery separately.
Move flexible use safely. Follow manufacturer guidance about running appliances while you are asleep or out.
Check your bill after the first month and switch back if it is not working for you, allowing for any exit fees.

Important limitations

There is no saving figure that applies to everyone. It depends on what you can move, and by how much.
Tariff prices and conditions change, and some tariffs close to new customers.
Economy 7 is an older two-rate arrangement with fixed night hours. It works differently from many smart tariffs.

Related tools and guides

Sources

Official sources checked 2 October 2026.