Cosy Octopus: How the Heat Pump Tariff Works

Cosy Octopus is an electricity tariff from Octopus Energy designed for homes using a heat pump or other eligible electric heating system.

Instead of charging the same electricity rate throughout the day, Cosy gives you three cheaper periods every day, totalling eight hours, with a more expensive peak period between 4pm and 7pm.

The idea is simple: run more of your heating, hot water and other electricity use during the cheaper Cosy periods, while reducing consumption during the evening peak.

What to know about Cosy Octopus

What is Cosy Octopus?

Cosy Octopus is a time-of-use electricity tariff designed primarily around the way heat pumps use energy.

Electric heating can significantly increase a home’s electricity consumption, particularly during winter. Cosy attempts to reduce the cost of that electricity by providing three cheaper periods spread across the day.

There are three different rates:

• a cheaper Cosy rate
• a standard day rate
• a more expensive peak rate

The price you pay therefore depends not only on how much electricity you use, but when you use it.

Cosy is an electricity-only tariff. If your property still has a gas supply, your gas would remain on a separate gas tariff.

How does Cosy Octopus work?

Cosy divides each day into three different electricity price bands.

The cheapest electricity is available during three Cosy periods. These have deliberately been spread across the day rather than concentrated entirely overnight.

There is then a three-hour peak period during the early evening when electricity is more expensive.

At all other times, you pay the normal Cosy day rate.

The current schedule is:

That gives you eight cheaper hours every day: three in the early morning, three during the afternoon and another two late in the evening.

What are the Cosy Octopus times?

The three Cosy Octopus cheaper periods are:

• 4am–7am
• 1pm–4pm
• 10pm–midnight

The peak period is:

• 4pm–7pm

These periods apply every day.

Having three separate cheaper periods is particularly useful for heat pumps because heating demand is spread throughout the day.

Rather than relying on one overnight window, Cosy gives you opportunities to warm your home or heat your hot water before the morning, before the evening peak and again later at night.

How much cheaper are the Cosy hours?

Octopus currently sets the three Cosy periods at 51% below the regional Cosy day rate.

The 4pm–7pm peak rate works in the opposite direction and is currently 50% above the regional day rate.

Your actual pence-per-kWh rates depend on where you live and whether you’re on the fixed or flexible version of Cosy.

This relationship between the three rates is what makes shifting consumption important.

Using more electricity during a Cosy period can be considerably cheaper than using the same amount during the evening peak.

What happens between the Cosy periods?

Not every hour outside the three cheaper periods is charged at the peak rate.

There are actually three price bands.

You pay the normal day rate during:

• midnight–4am
• 7am–1pm
• 7pm–10pm

Only the three hours between 4pm and 7pm are charged at the higher peak rate.

This is important because Cosy doesn’t require you to avoid electricity for most of the day.

The main opportunity is to move suitable electricity use into the Cosy periods and, where practical, reduce higher-consumption activities during the 4pm–7pm peak.

Why is there a 4pm–7pm peak rate?

The early evening is typically one of the busiest periods on the electricity grid.

People return home, cook dinner, use appliances, heat their homes and generally increase electricity consumption at roughly the same time.

Cosy encourages households to move some of that demand outside the evening peak.

For a heat pump household, that could mean warming the property during the afternoon Cosy period and allowing the home’s retained heat to reduce how hard the heat pump needs to work between 4pm and 7pm.

How practical that is will depend on your property, heating system, insulation and preferred indoor temperature.

Who can get Cosy Octopus?

Cosy isn’t available to every Octopus Energy customer.

It’s intended for households using eligible forms of electric heating.

Octopus currently lists the following as eligible:

• air source heat pumps
• ground source heat pumps
• electric boilers
• electric radiators

Other low-carbon heating systems may also be accepted, although eligibility can depend on the particular system.

Importantly, your heat pump doesn’t need to have been installed by Octopus Energy.

If you’re currently having an eligible heating system installed, Octopus also allows you to begin the process of moving onto Cosy.

Do I need a Cosy heat pump?

No.

Despite sharing the Cosy name, the Cosy Octopus tariff and Octopus’s Cosy heat pump are separate products.

You don’t need to own an Octopus Cosy heat pump to use the tariff.

An eligible heat pump installed by another company can qualify, as can other qualifying electric heating systems.

This means existing heat pump owners can consider Cosy without replacing their current heating equipment.

Do I need a smart meter for Cosy Octopus?

Yes.

Cosy is a time-of-use tariff, so Octopus needs to know how much electricity you consume during each half-hour period.

You’ll therefore need a compatible smart meter that Octopus can communicate with and collect half-hourly readings from.

Octopus currently supports compatible SMETS2 meters and certain SMETS1 meters.

If you’re already an Octopus customer, you can check the meter details shown in your online account.

If you’re moving to Octopus from another supplier and don’t yet have a suitable smart meter, you can switch your electricity supply first and arrange the smart-meter requirements afterwards.

Does Cosy Octopus have an exit fee?

No.

Octopus currently applies no exit fees or tie-ins to either the fixed or flexible version of Cosy.

That means you can switch to another Octopus tariff or move supplier without paying an exit penalty if Cosy no longer suits the way you use electricity.

How do you save money with Cosy Octopus?

Simply moving onto Cosy doesn’t automatically mean your electricity will cost less.

The tariff rewards households that can use more electricity during the cheaper periods and less during the 4pm–7pm peak.

With a heat pump, this could involve using your heating schedule to:

• warm your home during the 4am–7am period before the morning
• use the 1pm–4pm period to maintain or increase the home’s temperature before the evening peak
• heat your hot water during cheaper periods
• reduce unnecessary heating demand between 4pm and 7pm
• use the 10pm–midnight window for later heating or hot water requirements

You can also shift other flexible electricity consumption into these periods.

Dishwashers, washing machines, tumble dryers and home batteries are examples of loads that may be possible to schedule, where safe and practical.

The more of your household’s electricity use that can move away from the peak period and into the three Cosy windows, the more useful the tariff can become.

Do I have to turn my heat pump off from 4pm to 7pm?

No.

The peak period doesn’t mean you have to completely stop heating your home for three hours.

Comfort still matters, and allowing a property to become excessively cold simply to avoid the peak rate may not be sensible.

Instead, Cosy gives you an incentive to reduce the amount of expensive electricity you need during that period.

For example, some households may be able to gradually warm their home during the 1pm–4pm Cosy period so the heat pump has less work to do later in the evening.

Exactly how you schedule a heat pump will depend on the property, the heat pump and how quickly the building gains and loses heat.

Is Cosy Octopus only for heating?

No.

The Cosy rates apply to all electricity used in your home during each respective time period.

That means electricity used by your appliances, lighting, heat pump, hot water system, battery or other equipment during a Cosy period is charged at the Cosy rate.

Likewise, household electricity consumed between 4pm and 7pm is charged at the peak rate.

This gives you another way to make use of the cheaper periods beyond simply rescheduling your heating.

Can I use Cosy Octopus with solar panels?

Yes.

Having solar panels doesn’t automatically prevent you from using Cosy for your imported electricity.

Solar generation could also help reduce the amount of electricity you need to import from the grid during the day.

This can be particularly useful around the more expensive 4pm–7pm period when there is still enough solar generation available, although the amount produced will vary significantly by season and weather.

Your import and export tariffs are separate, so you’ll also need to consider which export tariff you use for surplus solar electricity.

Which export tariffs work with Cosy Octopus?

Octopus currently lists Cosy as compatible with:

• Octopus Outgoing Smart Export Guarantee
• Octopus Outgoing
• Agile Outgoing

Cosy isn’t compatible with every Octopus export tariff.

This is worth checking particularly carefully if you already have solar panels and a home battery, because moving your import tariff could affect which export options are available to you.

Is Cosy Octopus good for a home battery?

A battery can potentially work well alongside a time-of-use tariff.

You may be able to charge your battery during one of the cheaper Cosy periods and then use that stored electricity later when grid electricity is more expensive.

The 1pm–4pm Cosy period followed immediately by the 4pm–7pm peak creates an obvious opportunity for this type of load shifting.

However, whether it saves money depends on factors including:

• battery capacity
• charging and discharging losses
• your household consumption
• solar generation
• your export tariff
• and how your battery is configured

A battery household should therefore consider its import and export strategy together rather than choosing Cosy based only on the cheaper import periods.

Is Cosy Octopus good for an electric car?

You can charge an electric car while on Cosy, and electricity used during the Cosy periods would be charged at the corresponding cheaper rate.

However, Cosy isn’t specifically designed as an EV tariff.

If a large proportion of your electricity consumption comes from charging an electric vehicle, it may be worth comparing Cosy against Octopus’s dedicated EV tariffs such as Octopus Go and Intelligent Octopus Go.

Those tariffs provide dedicated overnight EV charging periods and may suit high-mileage EV households differently.

For a household with both a heat pump and an EV, the better tariff can depend on which technology accounts for the greater share of flexible electricity consumption.

Who is Cosy best for?

Cosy is primarily designed for households with relatively high electricity consumption from heating.

It could be particularly worth considering if you:

• have a heat pump or other eligible electric heating system
• can schedule some heating or hot water around the three Cosy periods
• have a compatible smart meter
• can reduce electricity use between 4pm and 7pm
• like the predictability of fixed daily time periods
• use a significant amount of electricity for heating

The three separate cheaper periods can make Cosy easier to use with heating than a tariff that provides only one overnight window.

Who should avoid Cosy Octopus?

Cosy may be less suitable if you use a lot of electricity between 4pm and 7pm and have little ability to move that consumption.

It may also be worth comparing alternatives if:

• you have an EV that accounts for a large share of your electricity consumption
• you have a home battery and want a different import/export tariff strategy
• you’re comfortable actively responding to half-hourly electricity prices
• you can’t shift your heat pump or hot water use
• you prefer one electricity rate throughout the day

The best tariff therefore depends on your whole household rather than the heating system alone.

How do I switch to Cosy Octopus?

I’m already an Octopus Energy customer

If Octopus already supplies your electricity, you’ll need an eligible heating system and a compatible smart meter.

Octopus must also be able to receive half-hourly readings from your meter.

Once the necessary meter connection is working, you can accept the Cosy terms and complete the switch.

I’m not currently with Octopus

If another supplier currently provides your electricity, you’ll normally need to move your supply to Octopus first.

You’ll initially join Octopus on another tariff while Octopus establishes the necessary smart-meter connection and confirms the meter can provide the required half-hourly data.

Once everything is ready, you can complete the move onto Cosy.

Switch to Octopus Energy →

You don’t need to have had your heat pump installed by Octopus to qualify.

Cosy Octopus FAQs

What are the Cosy Octopus cheap hours?

Cosy currently has three cheaper periods every day: 4am–7am, 1pm–4pm and 10pm–midnight. Together they provide eight hours at the Cosy rate.

What time is the Cosy Octopus peak rate?

The peak period runs from 4pm until 7pm every day.

What happens from 7pm until 10pm?

Electricity is charged at the normal Cosy day rate. The higher peak rate only applies between 4pm and 7pm.

Is Cosy Octopus just for heat pumps?

Not exclusively. Octopus also currently allows eligible homes with electric boilers and electric radiators to join. Other electric low-carbon heating systems may be considered.

Does my heat pump have to be installed by Octopus?

No. An eligible heat pump installed by another company can still qualify for Cosy.

Can I get Cosy while my heat pump is being installed?

Octopus says customers who are in the process of having an eligible heating system installed can begin switching to Cosy.

Do I need a smart meter?

Yes. Octopus needs a compatible smart meter from which it can receive half-hourly electricity readings.

Is Cosy Octopus fixed?

There are both fixed and flexible versions of Cosy. Fixed tariff rates remain unchanged for the relevant term, while flexible rates can change.

Is there a gas Cosy Octopus tariff?

No. Cosy is an electricity-only tariff. If you still use gas, your gas supply remains on a separate tariff.

Does Cosy Octopus have an exit fee?

No. Octopus currently says there are no exit fees or tie-ins on either version of Cosy.

Can I use Cosy Octopus with solar panels?

Yes. Solar panels don’t prevent you from using Cosy for imported electricity, although your choice of Cosy can affect which Octopus export tariffs you can combine with it.

Can I use Cosy Octopus with a battery?

Yes. A home battery could potentially be charged during cheaper Cosy periods and used later, although whether this is worthwhile depends on your battery, usage and export arrangements.

Do Cosy Octopus times change when the clocks change?

No. Octopus says the Cosy periods remain 4am–7am, 1pm–4pm and 10pm–midnight, with the peak period remaining 4pm–7pm.

Your In-Home Display can occasionally show something different around daylight-saving changes, but Octopus says its billing system uses the correct tariff periods.

Tariff rates, eligibility and terms can change. Always check the prices and tariff terms shown by Octopus Energy before switching.

Last checked: September 2026