Cosy Octopus: How the Heat Pump Tariff Works

Cosy Octopus is a time-of-use electricity tariff designed for homes with heat pumps and other eligible electric heating systems. It offers eight cheaper hours every day, spread across three periods, with a higher electricity rate between 4pm and 7pm.

This guide explains the Cosy Octopus rates, cheap hours, eligibility requirements and how the tariff works, helping you decide whether it could be a good fit for your home.

Tariff information checked: 2 November 2026.

Cosy Octopus tariff at a glance

Cosy’s main attraction is that its cheaper electricity periods are spread throughout the day, rather than being concentrated overnight.

That can be useful for homes with heat pumps, where heating demand continues throughout the day and particularly during colder months.

However, Cosy Octopus isn’t automatically cheaper than a standard electricity tariff. Whether you save money depends on your electricity rates, the amount you use and how much consumption you can shift away from the expensive evening peak.

Cosy Octopus rates and standing charges

Cosy Octopus has three electricity unit rates: a cheaper Cosy rate, a standard day rate and a more expensive peak rate.

The amount you pay per kilowatt-hour (kWh) depends on where you live and whether you choose the fixed or flexible version of the tariff.

Octopus currently structures its rates as follows:

For example, if your Cosy day rate were 30p/kWh:

• Your cheaper Cosy rate would be 14.7p/kWh.
• Your normal day rate would be 30p/kWh.
• Your peak rate would be 45p/kWh.

These figures are illustrative, not current tariff quotes.

The relationship between the rates makes the timing of your electricity consumption particularly important. In this example, using 1 kWh during the evening peak would cost more than three times as much as using it during a cheaper Cosy period.

What are the current Cosy Octopus rates?

Cosy Octopus prices vary by electricity region and tariff version, so there isn’t one set of unit rates or standing charges that applies to every household.

To find your actual prices, use the postcode checker on the official Cosy Octopus tariff page.

Check all four prices before deciding whether to switch:

1. The cheaper Cosy electricity rate.
2. The standard day electricity rate.
3. The higher peak electricity rate.
4. The daily standing charge.

It’s important to consider the standing charge alongside the unit rates, particularly when comparing Cosy with another tariff.

For the most accurate comparison, use your own electricity consumption rather than assuming you’ll save money simply because Cosy offers cheaper periods.

Cosy Octopus cheap hours and peak times

Cosy Octopus provides eight cheaper hours of electricity every day, divided into three separate periods.

The tariff follows the same daily schedule, including weekends.

These periods give you three opportunities to use cheaper electricity:

4am–7am: Early morning

This can be a useful period to warm your home before the day begins or heat your hot water before morning showers.

1pm–4pm: Afternoon

The afternoon Cosy period falls immediately before the expensive evening peak. Some households may benefit from gently warming their home or heating water during this time to reduce electricity consumption later.

10pm–midnight: Late evening

The final Cosy period offers another opportunity to heat water, charge a home battery or schedule other suitable electricity use.

What happens between the cheaper periods?

Electricity used outside the three Cosy periods isn’t necessarily charged at the expensive peak rate.

The higher rate applies only between 4pm and 7pm.

At all other times outside the cheaper periods, you pay the standard Cosy day rate.

That means there are 13 hours at the day rate, eight hours at the cheaper Cosy rate and three hours at the higher peak rate every day.

Why is electricity more expensive between 4pm and 7pm?

Electricity demand is typically higher during the early evening as people return home, prepare meals, use appliances and heat their properties.

Cosy Octopus encourages households to move some of their electricity consumption outside this period.

For homes with heat pumps, this could mean increasing heating output slightly during the cheaper afternoon period, allowing the building to retain some warmth through the more expensive evening hours.

How effective this is depends on your heating system, insulation, property and preferred indoor temperature.

How does Cosy Octopus work?

Cosy Octopus is designed to reward households that can adjust when they consume electricity.

Unlike a conventional single-rate tariff, where each kWh costs the same regardless of when it’s used, Cosy charges different prices at different times of day.

Your smart meter records how much electricity you consume during each half-hour period. Octopus then applies the appropriate tariff rate to that consumption.

For example:

• Electricity used to heat water at 5am is charged at the cheaper Cosy rate.
• Electricity used for normal household activities at midday is charged at the day rate.
• Electricity used by your heat pump or appliances at 5pm is charged at the higher peak rate.

Importantly, the Cosy rate applies to all household electricity used during the cheaper periods, not just the electricity consumed by your heating system.

This means you could also benefit from scheduling suitable appliances, battery charging or other electricity use during cheaper hours.

The tariff is designed with electric heating in mind, but your entire household’s electricity consumption affects whether it represents good value.

Cosy Octopus fixed vs flexible

Cosy Octopus is available in both fixed and flexible versions.

Both use the same three daily electricity periods, but they differ in how the prices you pay can change over time.

Fixed Cosy Octopus

With the fixed version, your quoted unit rates and standing charge remain unchanged for the agreed tariff term.

You still pay according to when and how much electricity you consume, but the unit prices themselves don’t change during that term.

This may appeal to households that prefer more certainty over their electricity prices.

However, a fixed unit rate doesn’t mean your monthly energy bill or Direct Debit will always stay the same. Your consumption can still vary substantially between summer and winter.

Flexible Cosy Octopus

The flexible version follows changes in Octopus’s underlying regional electricity prices.

When those prices change, your Cosy day, cheaper and peak rates can change too.

This means you could benefit from falling electricity prices, but you could also pay more if prices rise.

Neither version is automatically the best choice. Compare the actual quoted prices and terms before deciding.

Octopus currently describes Cosy as having no exit fees for either version, although you should check the conditions attached to your individual tariff offer.

Who is eligible for Cosy Octopus?

Cosy Octopus is intended for households with a heat pump or another eligible low-carbon electric heating system.

According to Octopus, qualifying systems include:

• Air source heat pumps.
• Ground source heat pumps.
• Electric boilers.
• Electric radiators.

Other electric heating systems may also be considered, but eligibility is determined by Octopus.

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

For example, a homeowner with an eligible heat pump installed by another company may still be able to join Cosy.

If your heating system is currently being installed, Octopus also allows you to begin the sign-up process, although the system must meet the applicable eligibility requirements.

Do you need an Octopus Cosy heat pump?

No.

The Cosy Octopus electricity tariff and Octopus’s Cosy-branded heat pumps are separate products.

You can qualify with an eligible heat pump from another manufacturer or installer.

Do you need a smart meter?

Yes. Cosy requires a compatible smart meter that Octopus can communicate with and collect half-hourly readings from.

Octopus supports compatible second-generation SMETS2 meters and certain first-generation SMETS1 meters.

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

If your smart meter isn’t currently communicating correctly, Octopus may need to resolve this before you can complete the tariff switch.

Can you get Cosy Octopus without a heat pump?

Potentially, but you must have another eligible electric heating system.

For example, Octopus accepts qualifying electric boilers and electric radiators.

Simply having an ordinary electricity supply, smart meter or electric vehicle doesn’t automatically make you eligible.

If you’re unsure whether your heating system qualifies, contact Octopus before switching.

Is Cosy Octopus worth it?

Cosy Octopus can be worthwhile for households that use a substantial amount of electricity for heating and can take advantage of its eight cheaper hours.

However, the financial benefit depends on more than simply owning a heat pump.

The most important factors are:

• How much electricity your household uses each year.
• How much of that electricity is consumed during Cosy periods.
• How much is consumed between 4pm and 7pm.
• The unit rates and standing charge in your region.
• Whether you can shift heating, hot water or other electricity demand.
• How Cosy compares with the alternative tariffs available to you.

When could Cosy Octopus save you money?

Consider a household that can heat its water during cheaper periods and gradually warm its property before the evening peak.

If that reduces the amount of electricity imported between 4pm and 7pm, the household may benefit from paying the cheaper Cosy rate for more of its consumption.

The difference between the two rates can be substantial.

Using the earlier illustrative rates of 14.7p/kWh during Cosy periods and 45p/kWh during the peak:

This demonstrates the potential value of shifting suitable consumption away from the expensive period.

However, it’s only an illustration of the tariff’s pricing. It doesn’t account for changes in heating efficiency, additional electricity needed to preheat a property or other practical limitations.

When might Cosy Octopus be more expensive?

Cosy may be less attractive if your household naturally uses substantial amounts of electricity during the evening peak and you can’t reasonably move that consumption.

For example, a poorly insulated home might lose heat relatively quickly, making it difficult to reduce heating demand between 4pm and 7pm without affecting comfort.

Households with large electric vehicle charging requirements may also find a dedicated EV tariff more suitable.

And while the cheaper Cosy rate can look attractive, the other rates and standing charge may differ from those of a standard tariff.

A meaningful comparison therefore needs to consider your entire electricity bill, rather than focusing exclusively on the cheapest unit rate.

How to compare Cosy Octopus with your current tariff

For an accurate comparison, you need to estimate how much electricity you use during each of Cosy’s three price bands.

Your annual Cosy electricity cost can then be calculated as:

Cosy electricity cost =

Electricity used during Cosy periods × Cosy rate

• Electricity used during day-rate periods × Day rate
• Electricity used during peak periods × Peak rate
• Annual standing charges.

You can then compare that result with the annual cost of your existing tariff using the same total electricity consumption.

If you have access to your historical half-hourly smart meter data, that provides a better starting point than simply estimating your usage.

You should also consider how your consumption might change if you adjusted your heat pump or hot water schedule.

How to save money on Cosy Octopus

The key to making Cosy work effectively is to move suitable electricity consumption into cheaper periods without unnecessarily increasing the amount of energy your household needs.

For a heat pump household, that usually means finding a balance between cheaper electricity prices, heating efficiency and maintaining a comfortable indoor temperature.

1. Make use of the afternoon Cosy period

The 1pm–4pm period is particularly interesting because it comes immediately before the higher evening rate.

Some households may be able to increase their heating target slightly during this period, allowing the property to retain more warmth between 4pm and 7pm.

However, the ideal approach will depend on how well your home retains heat and how efficiently your heat pump operates at different temperatures.

2. Schedule hot water during cheaper hours

If your home has a hot water cylinder, you may be able to schedule water heating during one or more Cosy periods.

This can reduce the need to heat water using more expensive electricity later in the day.

Remember that some heat pump systems prioritise hot water production over space heating, so your schedule should allow enough time for both.

You should also retain any hygiene cycles or other safety settings required by your system.

3. Reduce unnecessary peak consumption

Between 4pm and 7pm, try to avoid running electricity-intensive equipment that could reasonably operate at another time.

This might include EV charging, battery charging or suitable appliances.

You don’t need to stop using electricity altogether. The aim is to reduce unnecessary expensive consumption while keeping your home comfortable.

4. Avoid unnecessarily switching your heat pump off

Heat pumps generally work most efficiently when operating steadily at relatively low heating temperatures.

Repeatedly switching the heating off and then asking the system to rapidly warm a cold property can reduce efficiency.

A modest adjustment to your heating schedule may therefore be more effective than shutting the system down completely during the peak.

Octopus provides specific heat pump scheduling guidance for customers using Cosy, although settings should always be appropriate for your particular heating system.

5. Consider your other electricity consumption

Cosy’s cheaper rates aren’t limited to your heating.

Depending on your household and equipment, you may also be able to schedule an EV charger, home battery or other suitable electricity use.

For appliances such as washing machines and tumble dryers, follow the manufacturer’s instructions and fire-safety guidance rather than running them unattended simply to access a cheaper rate.

Cosy Octopus vs other Octopus tariffs

Cosy isn’t the only Octopus tariff that allows customers to benefit from cheaper electricity at particular times.

Depending on your household, Agile Octopus or one of Octopus’s dedicated EV tariffs may also be worth considering.

Cosy Octopus vs Agile Octopus

Both tariffs reward households that can adjust their electricity consumption, but they work differently.

Cosy offers predictable cheaper periods that remain the same every day.

Agile Octopus has prices that change every 30 minutes, with the cheapest periods varying from day to day.

Agile can occasionally offer very cheap or even negative electricity prices, but it can also become expensive when wholesale costs are high.

For households that prefer predictable heating schedules, Cosy may be easier to manage.

For households with flexible equipment, automation or home batteries, Agile could offer different savings opportunities.

You can explore current and historical electricity prices using our Agile Octopus pricing dashboard.

Cosy Octopus vs Octopus Go

Octopus Go offers a dedicated overnight charging period and is designed for electric vehicle owners.

Cosy provides cheaper electricity across three periods throughout the day.

For households with a heat pump but relatively little EV charging, Cosy’s additional daytime cheap hours may be useful.

However, households that charge a large electric vehicle battery regularly should compare the total annual cost of both tariffs.

Cosy Octopus vs Intelligent Octopus Go

Intelligent Octopus Go offers an extended cheaper overnight period alongside smart charging for eligible vehicles or chargers.

If you own both a heat pump and an electric vehicle, neither tariff is necessarily the obvious winner.

The better option may depend on how much electricity your heat pump consumes, how much charging your EV requires and how much household consumption you can move into each tariff’s cheaper periods.

The most useful comparison is based on your total household electricity consumption, not just the price of charging the car.

Can you use Cosy Octopus with solar panels, batteries or an EV?

Yes. Having additional low-carbon technology doesn’t automatically prevent you from joining Cosy, provided you meet the tariff’s eligibility requirements.

However, each technology introduces additional considerations.

Cosy Octopus with solar panels

Solar panels can help reduce the electricity your home needs to import from the grid.

If your panels generate electricity during the day, you may be able to reduce consumption charged at Cosy’s day rate or, depending on the season, its evening peak rate.

However, you should also consider your export tariff.

Octopus currently lists Cosy as compatible with:

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

Not every Octopus export tariff can be combined with Cosy.

If you already receive payments for exported electricity, check whether changing your import tariff would affect your export arrangements.

Cosy Octopus with a home battery

A home battery can potentially make Cosy’s cheaper periods more useful.

For example, you could charge a compatible battery during the 1pm–4pm Cosy period and discharge it to power your home between 4pm and 7pm.

This can reduce the amount of electricity you need to buy at the more expensive peak rate.

However, battery charging and discharging aren’t perfectly efficient.

You also need to account for the battery’s usable capacity, charging speed, solar generation and any export revenue you might otherwise receive.

A battery doesn’t automatically make Cosy the cheapest tariff, particularly if another import-and-export arrangement would produce better overall results.

Cosy Octopus with an electric car

You can charge an EV while on Cosy, and the electricity used will be charged at the relevant rate for that time of day.

However, Cosy isn’t specifically designed for electric vehicle charging.

If you drive a high annual mileage and frequently charge at home, compare Cosy with dedicated EV tariffs before deciding.

For households with both a heat pump and EV, the key question is which tariff best suits your combined electricity consumption.

How to switch to Cosy Octopus

The switching process depends on whether you’re already supplied by Octopus Energy.

I’m already an Octopus Energy customer

If you’re already with Octopus, you’ll need to confirm that your heating system is eligible and that your smart meter is compatible.

Octopus must be able to receive the necessary half-hourly readings before your switch can be completed.

Once your meter is connected and the eligibility requirements are satisfied, Octopus will ask you to accept the relevant tariff terms.

Your account can then be moved onto Cosy.

I’m not currently with Octopus Energy

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

You’ll initially join on an interim tariff while Octopus establishes the necessary smart meter connection and confirms your eligibility.

Once your smart meter is communicating and you meet the other requirements, you can complete the move to Cosy.

Thinking of joining Octopus Energy?

Our guide to switching to Octopus Energy explains the joining process, including how eligible new customers can receive £50 account credit through a referral.

Remember that joining Octopus doesn’t automatically place you onto Cosy. You’ll still need to meet the tariff’s eligibility and smart meter requirements.

Cosy Octopus FAQs

What are the Cosy Octopus cheap hours?

The cheaper periods are 4am–7am, 1pm–4pm and 10pm–midnight every day. Together, these provide eight hours of cheaper electricity.

What time is the Cosy Octopus peak rate?

The higher peak rate applies between 4pm and 7pm every day. All other hours outside the cheaper Cosy periods are charged at the standard day rate.

Is Cosy Octopus cheaper than a standard tariff?

It can be, particularly for households able to use substantial amounts of electricity during the cheaper periods and reduce evening peak consumption. However, actual savings depend on your regional rates, standing charge and usage pattern.

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

No. You can continue heating your home during the peak period. Some households may benefit from reducing heating demand during those hours, but comfort and heat pump efficiency should remain priorities.

Is Cosy Octopus fixed or variable?

Both versions are available. Fixed Cosy keeps your quoted rates unchanged for the agreed term, while flexible Cosy rates can increase or decrease.

Can I use Cosy Octopus without a heat pump?

Yes, if you have another eligible electric heating system, such as an electric boiler or electric radiators. Octopus determines eligibility for other heating systems.

Does my heat pump have to be installed by Octopus?

No. Eligible heat pumps installed by other companies can qualify for the tariff.

Can I have Cosy Octopus and gas?

Yes. Cosy is an electricity-only tariff, so any gas supply would remain on a separate gas tariff.

Does Cosy Octopus have exit fees?

Octopus currently advertises no exit fees for either version of Cosy. However, its wider smart tariff rules include restrictions on how frequently customers can move between smart tariffs. Always check the terms attached to your tariff before switching.

Do Cosy Octopus times change when the clocks change?

No. Octopus says the three cheaper periods and the evening peak remain at the same local clock times throughout the year.

Some smart meter In-Home Displays may show confusing information around daylight-saving changes, but Octopus says its billing systems account for these changes correctly.

Can Cosy Octopus work with solar panels and a battery?

Yes, provided you meet the tariff’s eligibility requirements. Solar generation and battery storage may help reduce expensive grid imports, although savings depend on your equipment, consumption and export tariff.

Is Cosy Octopus suitable for storage heaters?

Don’t assume so. Cosy is intended for eligible electric heating systems, while the best tariff for traditional storage heaters can depend on their controls and charging requirements. Check eligibility with Octopus and compare any dedicated storage-heating tariffs available to you.

Before switching: Tariff prices, eligibility requirements and terms can change. Check your personalised rates, standing charge and tariff conditions directly with Octopus Energy.

Sources: Cosy Octopus tariff information · Smart tariff terms and conditions · Heat pump scheduling guidance