Cosy Octopus is a smart electricity tariff designed for households with a heat pump. It offers cheaper electricity during set off-peak periods, including an afternoon window that can be useful for pre-heating your home or hot water, alongside a more expensive peak period in the early evening.
This page explains how Cosy Octopus works, who can join, who it suits and how to find the latest Cosy Octopus tariff rates.
Cosy Octopus tariff rates
What is Cosy Octopus?
Cosy Octopus is a three-rate electricity tariff designed for homes with heat pumps. Instead of charging one unit rate all day, Octopus splits electricity into cheaper off-peak periods, a standard day rate and a more expensive early-evening peak rate.
The cheaper periods are called Cosy Hours. They are designed to encourage households to shift heating, hot water, battery charging and other flexible electricity use away from the busiest parts of the day.
Cosy Octopus is a whole-home tariff, not a tariff that only applies to your heat pump. The rate in each period applies to everything using electricity in your home, including appliances, hot water, battery charging and EV charging.
How does Cosy Octopus work?
Cosy Octopus gives you three cheaper electricity periods each day, known as Cosy Hours:
- 4am to 7am
- 1pm to 4pm
- 10pm to midnight
That gives you eight hours of cheaper electricity across the day. The most expensive period is 4pm to 7pm, when electricity is charged at the peak rate. The remaining hours are charged at the standard day rate.
In practice, the aim is to move as much flexible electricity use as possible into Cosy Hours and away from the 4pm to 7pm peak. For heat pump households, this may mean pre-heating the home or hot water during the cheaper periods, then reducing demand during the early evening.
The 1pm to 4pm window is especially useful because it comes directly before the peak period. A heat pump can warm the home or hot water cylinder before 4pm, helping reduce how much electricity is needed during the most expensive part of the day.
Because Cosy Octopus is a whole-home tariff, the same approach can apply to other flexible loads. Dishwashers, washing machines, tumble dryers, EV charging and home battery charging can all be shifted into Cosy Hours where practical.
Who is Cosy Octopus best for?
Cosy Octopus is most likely to suit households that can move a meaningful amount of electricity use into the three Cosy Hours windows and reduce demand during the 4pm to 7pm peak.
It may work particularly well for:
- Heat pump owners with a well-insulated home that can stay warm through the early-evening peak without needing constant heating
- Homes that hold heat well, such as properties with underfloor heating, solid floors or good heat-retention measures
- Heat pump households with a home battery that can charge during Cosy Hours and discharge during the peak period
- Homes with a hot water cylinder that can be heated during cheaper periods and used later in the day
- Solar and battery households where heating is a major part of electricity use
- Electric boiler or electric radiator households that can schedule heating into cheaper periods rather than running constantly
- Households willing to programme heating, hot water, appliances or battery charging around the tariff windows
The key point is flexibility. Cosy Octopus works best when your home can use more electricity during the cheaper periods and less during the expensive 4pm to 7pm window. If your heating has to run heavily during peak times, the tariff may be less effective.
Who should avoid Cosy Octopus?
Cosy Octopus is unlikely to suit households that:
- Use storage heaters and are better matched to an Economy 7-style tariff
- Live in a poorly insulated home that loses heat quickly once the heating eases off
- Have high, inflexible electricity use between 4pm and 7pm
- Cannot or do not want to adjust heating, hot water or appliance schedules around the tariff windows
- Do not have a compatible smart meter sending half-hourly readings
- Have a heat pump setup that needs to run continuously and cannot realistically shift demand away from the peak period
The main risk is the 4pm to 7pm peak. If your home cools quickly, your heating has to work hard through that window, or your household routine means heavy electricity use in the early evening, Cosy Octopus may become more expensive than expected.
Cosy works best when your home can make use of the cheaper periods and reduce demand during peak hours. If that does not match how your heating or household routine works, a simpler tariff may be a better fit.
Eligibility
To be eligible for Cosy Octopus, you will need:
- To be an Octopus Energy electricity customer, or switch to Octopus first
- A compatible smart meter that Octopus can communicate with and use for half-hourly billing
- An eligible electric heating system, such as an air source heat pump, ground source heat pump, hybrid heat pump, electric boiler or electric radiators
Your heating system does not need to have been installed by Octopus. Homes that are part-way through a heat pump installation may also be able to switch, provided the setup meets Octopus’s requirements.
Storage heaters are not eligible for Cosy Octopus. They are usually better suited to an Economy 7-style tariff with a longer overnight cheap-rate period.
How to switch to Cosy Octopus
If you’re already with Octopus
You can usually switch to Cosy Octopus through your online account or the Octopus app once your smart meter is communicating correctly and your heating setup meets the eligibility requirements.
If Cosy Octopus does not appear as an available option, or your heating setup needs to be checked, you may need to contact Octopus directly.
If you’re switching to Octopus
New customers are normally moved onto Flexible Octopus first while the supply transfer and smart meter setup are completed. Once your account is active, your smart meter is working correctly and your heating setup is confirmed as eligible, you can switch to Cosy Octopus.
Find out more about switching to Octopus Energy and receiving £50 credit.
Will Cosy Octopus save you money?
Whether Cosy Octopus saves you money depends on how well your home matches the tariff windows.
The biggest factors are:
- How much electricity you can move into the eight cheaper Cosy Hours
- Whether your home can stay comfortable through the 4pm to 7pm peak without heavy heating use
- How well insulated your property is
- How much of your electricity use comes from heating and hot water, rather than general household demand
- Whether you can schedule appliances, battery charging or EV charging into the cheaper periods
Cosy Octopus is most likely to work well in a well-insulated home with a heat pump, hot water cylinder or battery that can be programmed around the cheaper windows. In that setup, you can heat the home or water before the peak period and reduce how much electricity you use when rates are highest.
It may work less well in a poorly insulated home, or in a household that uses a lot of electricity between 4pm and 7pm. If the heating has to run hard through the peak period, or your routine cannot shift away from early evening use, the higher peak rate could reduce or even wipe out the benefit of the cheaper windows.
For a realistic estimate, use your annual electricity usage, your postcode and your actual heating pattern. The key question is not just “is the off-peak rate cheaper?” but “how much of my real usage can I move into those cheaper periods?”
Cosy Octopus FAQs
Do I need a heat pump to get Cosy Octopus?
No, but you do need an eligible electric heating system. Cosy Octopus is available to households with an air source heat pump, ground source heat pump, hybrid heat pump, electric boiler or electric radiators.
Storage heaters are not eligible and are usually better suited to an Economy 7-style tariff.
What are the Cosy Hours on Cosy Octopus?
Cosy Octopus has three cheaper periods each day:
- 4am to 7am
- 1pm to 4pm
- 10pm to midnight
Together, these give you eight hours of cheaper electricity each day.
When is the peak rate on Cosy Octopus?
The peak period runs from 4pm to 7pm every day. Electricity used during this window is charged at the higher peak rate.
This is the main period to avoid where possible, especially for heating, hot water, EV charging and other high-use appliances.
Does the whole home get the cheap rate during Cosy Hours?
Yes. Cosy Octopus is a whole-home tariff, so the cheaper Cosy Hours rate applies to all electricity used in the property during those windows.
That includes your heating system, appliances, hot-water heating, EV charging and home battery charging.
Can I get Cosy Octopus with electric radiators or an electric boiler?
Yes. Cosy Octopus is available to homes with electric radiators or an electric boiler, as well as heat pumps.
Your heating system does not need to have been installed by Octopus.
Is Cosy Octopus available for storage heaters?
No. Cosy Octopus is not designed for storage heaters.
Homes with storage heaters are usually better matched to an Economy 7-style tariff, which provides a longer overnight cheap-rate period for charging the heaters.
Can I be on Cosy Octopus and Outgoing Octopus at the same time?
Yes. Cosy Octopus covers the electricity you import from the grid, while Outgoing Octopus covers electricity you export back to the grid.
This means some solar and battery households may use Cosy Octopus for import and an Octopus export tariff for surplus solar generation.
Does Cosy Octopus work without a smart meter?
No. You need a compatible smart meter that Octopus can communicate with and use for half-hourly billing.
Without half-hourly readings, Octopus cannot bill the three Cosy Hours windows, the day rate and the peak period correctly.