What Is Off-Peak Electricity and When Is the Cheapest Time to Use It?

Quick links:

• UK off-peak electricity times by major energy supplier
• Economy 7 vs. smart time-of-use tariffs: which do you need?
• The 2025 RTS meter phase-out: important information for legacy customers
• Is off-peak electricity actually cheaper? The 40 percent rule
• Best appliances to run during off-peak hours
• How to split an off-peak energy bill fairly with other bill payers
• Common myths and FAQs about off-peak energy

Off-peak electricity is a pricing system where electricity costs less during periods of lower demand, usually overnight between 10pm and 8am. Some households could reduce their energy bills by using electricity during off-peak hours rather than during the day.

These cheaper off-peak rates are available on a multi-rate tariff, like Economy 7 or another time-of-use tariff, with a compatible electricity meter. Some energy suppliers offer these tariffs, but they aren't available with every energy package.

Off-peak tariffs aren’t right for everyone. You'll only save money if it's feasible to use a lot of electricity during off-peak hours.

Another way to take control and get peace of mind over energy costs is an Unlimited Energy deal. Pay the same each month to use as much as you need, meaning no stress about your usage, no matter what time of day you need to use electricity.

Keep reading to learn how off-peak electricity works, who it's best for, and whether it could help lower your energy bills.

Off-peak hours vary depending on your supplier, tariff, meter type, and where you live.

Most Economy 7 customers get the cheaper rate for seven hours overnight, but it's always worth checking your tariff details to confirm your exact times.

These times can change during British Summer Time, so always check your supplier's latest information before relying on off-peak rates.

Economy 7 and smart time-of-use tariffs both offer cheaper electricity at certain times, but they work differently.

Economy 7 and Economy 10 are traditional multi-rate tariffs offered by some energy suppliers. They use dual-rate meters to charge a cheaper rate during set off-peak hours and a higher rate during the day.

Pros

• Simple off-peak pricing.
• Can help lower bills if you use most of your electricity overnight.
• Suitable for homes with storage heaters or hot water tanks.

Cons

• Daytime electricity is usually more expensive.
• Off-peak hours are fixed.
• You'll need to plan your energy use to make the most of the cheaper rates.

Smart time-of-use tariffs

Smart time-of-use tariffs are available from some suppliers and you’ll need a compatible smart meter to access them. Instead of fixed overnight hours, electricity prices change throughout the day, depending on demand.

Some tariffs offer cheaper overnight charging for electric vehicles, lower weekend rates, or other discounts. Depending on the supplier, you may need an electric vehicle, heat pump, or home battery to qualify.

Pros

• More flexibility than Economy 7.
• Can offer cheaper charging for electric vehicles.
• Better control over when you use energy.

Cons

• Prices can change throughout the day.
• Not available from every supplier.
• Some tariffs have additional eligibility requirements.

If neither of these options sound appealing ’cause you don’t want to plan your energy use, or don’t have the time, a standard tariff may be a better option. Read our guide to fixed energy tariffs to learn how they compare with off-peak and time-of-use tariffs. Or check out how an Unlimited Energy deal works if you’re looking for extra peace of mind about your energy costs.

Important: The Radio Teleswitch Service (RTS) was phased out in June 2025. If your home still relies on an RTS meter to switch between peak and off-peak electricity rates, you may need a new meter.

RTS meters were commonly used with older Economy 7 and Economy 10 tariffs. Since the service ended, they may no longer switch correctly between day and night rates, which could lead to incorrect bills.

Your energy supplier should have contacted you if your property is affected. If you're unsure, it's worth getting in touch with them to arrange a smart meter upgrade.

You might have an RTS meter if:

• you have an older Economy 7 or Economy 10 tariff,
• your home uses storage heaters or an immersion heater,
• your meter switches automatically between day and night rates.

Not sure what type of meter you have? Read our guide to what an electricity meter looks like so you can find it before contacting your supplier.

Off-peak electricity can save you money, but only if you use enough electricity during cheaper hours. That's because off-peak tariffs often have higher daytime rates than standard tariffs.

As a general rule, you'll usually need to shift around 30% to 45% of your electricity use to off-peak hours before you start seeing real savings. This is sometimes known as the 40% rule.

Break-even example

If you're not sure which tariff is right for you, speak to your energy supplier for advice.

If you choose a variable off-peak tariff, it will be affected by the Energy Price Cap and can change over time. Read our guide to the Energy Price Cap to find out how these changes could affect your bills.

A fixed-price off-peak tariff won’t be affected by the Price Cap.

On an off-peak tariff, you save the most money by using high-energy appliances during the cheaper overnight hours.

High-impact appliances

Using these appliances at night can make the biggest difference to your energy bill:

• Electric vehicle (EV) chargers
• Storage heaters
• Immersion water heaters
• Home battery storage systems
• Tumble dryers
• Washing machines
• Dishwashers

Many modern appliances have delay-start timers, making it easy to run them overnight.

Low-impact appliances

These appliances use much less electricity, so changing when you use them is unlikely to make a noticeable difference to your bill:

• TVs
• Laptops
• Phone chargers
• LED lighting
• Wi-Fi routers

If you don’t want to constantly plan when to use electricity, a standard tariff may be a better fit.

An Unlimited Energy deal can also give you peace of mind about your energy costs, giving you all the energy you need to use for a set price throughout your contract, like an unlimited mobile contract!

Splitting the cost of an off-peak energy bill can be difficult, especially if one of you charges an electric vehicle or regularly uses high-energy appliances overnight.

If you're a landlord or lead tenant, you must follow Ofgem's Maximum Resale Price rules and can't charge more than you've paid for the energy.