Cosy Octopus Tariff 2026
Cosy Octopus is Octopus Energy's electricity tariff for homes with a heat pump. You get several hours of cheaper electricity a day, timed so the heat pump can warm the house and hot water when power is at its cheapest. Get the timing right and it takes a fair chunk off your winter heating bill. You do not need to have bought the heat pump from Octopus to move onto it.
Quick Answer
Cosy Octopus gives heat pump homes three cheap off-peak windows a day (roughly 4-7am, 1-4pm and 10pm-midnight) well below the peak rate, against a higher rate in the 4-7pm peak. Any heat pump home with a smart meter can use it, not only Octopus installs. The saving comes from heating the house and hot water during the cheap windows.
Independent guide, 2026. Solar Info UK is not affiliated with Octopus Energy.
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
How the Cosy Octopus tariff works
Cosy Octopus is a time-of-use tariff: instead of one flat rate all day, the day is split into cheap, standard and peak periods. The cheap windows fall when wholesale power is usually lowest. You run the heat pump hard then, warming the house and the hot water cylinder, so it barely needs to touch the pricey 4pm to 7pm slot. A smart thermostat or the heat pump's own schedule handles the timing.
- Three cheaper off-peak windows each day for pre-heating
- A higher rate during the 4pm to 7pm evening peak
- A standard rate the rest of the time
- Designed to pair with smart heat pump controls or a hot water cylinder
- Open to any heat pump home with a smart meter, regardless of who installed the unit
Cosy Octopus rates and off-peak hours
Rates vary by region and change over time, so check the live figure on Octopus before you switch. Broadly, the cheap windows sit well below the daytime standard rate and the evening peak sits above it. What matters is the shape of the day, not the exact pence: heat in the cheap windows, stay off the peak.
| Period | Typical window | Relative rate |
|---|---|---|
| Off-peak (early morning) | ~04:00–07:00 | Cheapest |
| Off-peak (afternoon) | ~13:00–16:00 | Cheapest |
| Off-peak (late evening) | ~22:00–00:00 | Cheapest |
| Standard | Remaining hours | Mid |
| Peak | ~16:00–19:00 | Highest |
Indicative windows. Octopus sets exact Cosy times and rates by region and updates them periodically. Verify current rates at octopus.energy before switching.
Thinking about a heat pump?
Cosy Octopus only pays off once you have a heat pump fitted. Compare quotes from independent MCS installers first.
Get a Quote ↓Is the Cosy Octopus tariff worth it?
For most heat pump homes, yes, as long as you can move heating into the cheap windows. On a flat single rate you pay the same price for every unit, peak hours included. Cosy lets you do most of the heating when power is cheapest, which adds up over a winter. The catch is the higher 4pm to 7pm rate, so it suits homes that can pre-heat and then leave the peak alone, ideally with a hot water cylinder or some thermal mass to hold the heat.
Cosy works well if you
- Have a heat pump and a smart meter
- Can schedule heating into the cheap windows
- Have a hot water cylinder to heat off-peak
- Can avoid heavy use in the 4–7pm peak
Look elsewhere if you
- Need heavy heating during the evening peak
- Have no smart controls to shift load
- Also own an EV and want the cheapest overnight rate (see Intelligent Octopus Go)
- Have solar and a battery (a Flux-style export tariff may earn more)
Cosy Octopus vs other heat pump tariffs
| Tariff | Best for | Shape |
|---|---|---|
| Cosy Octopus | Heat pump homes | Three cheap daily windows, one evening peak |
| Intelligent Octopus Go | Heat pump + EV homes | Cheap overnight block (best for charging a car) |
| Standard variable | Homes that cannot shift load | Flat rate all day, no peak penalty |
If you have an EV as well as a heat pump, compare Cosy against Intelligent Octopus Go, which gives one cheap overnight block ideal for charging a car. For the wider Octopus range including solar export tariffs, see our best Octopus tariffs guide.
Cosy Octopus Tariff FAQ
What is the Cosy Octopus tariff?
Cosy Octopus is a time-of-use electricity tariff from Octopus Energy built for homes with a heat pump. It gives three cheaper off-peak windows each day (roughly early morning, early afternoon and late evening) so you can run the heat pump when power is cheapest, in exchange for a higher rate during the 4pm to 7pm evening peak.
What are the Cosy Octopus off-peak hours?
Cosy typically has three cheap windows a day, around 4am to 7am, 1pm to 4pm and 10pm to midnight, with a peak period roughly 4pm to 7pm. Exact times vary by region and Octopus updates them periodically, so check your live rates in the Octopus app before relying on a specific window.
Do I have to buy a heat pump from Octopus to get the Cosy tariff?
No. Cosy Octopus is open to any home with a heat pump and a smart meter, regardless of who installed the unit. You can use an independent MCS installer and still switch onto Cosy once your system is commissioned.
Is Cosy Octopus cheaper than a standard tariff for a heat pump?
For most heat pump homes that can shift heating into the cheap windows, yes. The saving comes from heating the house and hot water during the off-peak periods and avoiding the expensive 4pm to 7pm peak. If you cannot shift load away from the evening peak, the higher peak rate can cancel out the benefit.
Cosy Octopus or Intelligent Octopus Go for a heat pump?
Cosy is built specifically for heat pumps, with several cheap daytime windows for pre-heating. Intelligent Octopus Go is built for EV charging, with one long cheap overnight block. If you have both a heat pump and an EV, compare the two, Go can suit if most of your shiftable load is overnight car charging, while Cosy suits homes whose main flexible load is heating.
Related Guides
Octopus Heat Pump
Octopus heat pump cost, the Cosy tariff, and how installers compare.
Intelligent Octopus Go
The cheap ~7p overnight EV charging tariff, eligibility and pairing it with solar.
Heat Pump Cost
Full price breakdown by type and home size, plus running costs.
Air Source Heat Pumps
Cost, best brands, running costs, and pros and cons for UK homes.
Sources
Last updated: June 2026
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He researches every battery and inverter brand against manufacturer datasheets, MCS and Ofgem data, and feedback from the MCS-certified installers in our directory before publishing.
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