Cosy Octopus is Octopus Energy’s smart electricity tariff for homes heated by a heat pump, electric boiler or electric radiators. It splits the day into three pricing windows: eight hours of cheap electricity (the “Cosy Hours”), a more expensive evening peak, and a standard day rate covering everything else. The idea is simple. Run your heating hard when electricity is cheap, ease off when it’s expensive, and let the building hold onto the warmth in between.
This page explains how the Octopus Cosy tariff actually works, what the three-rate structure looks like in practice, who it suits, and where it can backfire. Cosy can save a typical heat pump household a useful amount of money each year. It can also cost a poorly insulated home more than a flat tariff. Both things are true, and the difference is mostly down to how your home behaves.
What is Octopus Cosy?
Cosy Octopus is a three-rate time-of-use electricity tariff designed around the way modern electric heating actually runs. Heat pumps, in particular, are most efficient when they run for long periods at moderate output rather than blasting on and off, and they pair naturally with a tariff that rewards shifting load into specific hours.
The tariff has three daily off-peak windows known as Cosy Hours, a standard day rate for most hours, and a peak window from 16:00 to 19:00 priced well above the day rate. You need a smart meter sending half-hourly readings, an Octopus electricity supply, and an eligible heat source: an air source, ground source or hybrid heat pump, an electric boiler, or electric radiators.
As of March 2026, Octopus moved Cosy from a flexible (variable) tariff with no exit fees to a 6-month fixed offering with a £25 exit fee. The three Cosy Hours windows and the peak window have not changed. Storage heaters are not eligible for Cosy and have their own tariff, called Snug Octopus.
The keyword to keep in mind: Cosy is a whole-home tariff, not a heat pump tariff in a narrow sense. The rate that applies at any moment applies to everything in your house, from the heat pump to the kettle to the EV charger.
How does Octopus Cosy work?
The structure is built around three off-peak windows every single day:
- 04:00–07:00 (early morning)
- 13:00–16:00 (afternoon)
- 22:00–00:00 (late evening)
That is eight hours of cheap electricity across the day, currently priced around 51% below the standard day rate in your region. The peak window runs from 16:00–19:00 and is priced roughly 50% above the day rate. The remaining hours sit at the day rate itself, which is broadly comparable to Octopus’s Flexible tariff for your area.
In practice, the strategy looks like this. Programme the heat pump to run harder during each Cosy Hours window, pushing the indoor temperature a degree or two above your normal setpoint and heating the hot water cylinder while you are at it. Then ease off through the 16:00–19:00 peak, letting the building’s thermal mass carry the warmth through three hours of expensive electricity. The heat pump may still run a little through peak if it has to, but the goal is to keep it close to ticking over.
Because the rates apply to the whole home, the same logic extends well beyond heating. Dishwashers and washing machines on delay timers, EV charging on a basic schedule, and home battery charging can all be shifted into Cosy Hours. The afternoon dip (13:00–16:00) is particularly useful because it lines up neatly with the period just before peak, letting the home arrive at 16:00 already warm.
One quirk worth flagging: in-home displays sometimes show the off-peak rate kicking in at slightly the wrong time, especially around daylight saving changes. Your bill is calculated correctly on the Octopus side. The display is the bit that can drift.
Current Octopus Cosy rates
Rather than quote specific unit rates that will be out of date within weeks, the structure is the part to understand:
- Off-peak (Cosy Hours): roughly 51% below the day rate
- Peak (16:00–19:00): roughly 50% above the day rate
- Day rate (all other hours): broadly similar to Octopus Flexible for your region
Standing charges and exact unit rates vary by region and change as wholesale prices move. Since March 2026, rates are fixed for six months at a time, with a £25 exit fee if you leave before the term is up. For the live rates in your postcode, the official rate checker on the Octopus website is the source to use.
Who is Octopus Cosy good for?
Cosy works well for households that can genuinely bias their electricity use toward the three Cosy Hours windows and ease off through peak. In rough order of best fit:
- Heat pump owners with a well-insulated home. Air source, ground source or hybrid. The better the insulation, the more easily the building coasts through the 16:00–19:00 peak without the heat pump kicking back in.
- Properties with reasonable thermal mass. Concrete floors, underfloor heating, solid walls, properties built or retrofitted with heat-retention in mind. Thermal mass is what lets you pre-heat during the afternoon Cosy Hours and still be comfortable at 18:30.
- Heat pump owners with a home battery. Charge the battery during Cosy Hours, run the heat pump from stored energy through peak. This is the cleanest version of the strategy.
- Hot water cylinder owners. A well-insulated cylinder heated once or twice during Cosy Hours will hold useable hot water through the evening, including peak.
- Solar and battery households whose heat pump load is the dominant slice of electricity use. With Cosy on import and Outgoing Octopus on export, this can be a strong combination.
- Electric boiler or electric radiator households in homes where the heating runs on a schedule rather than constantly.
- Anyone willing to actually programme the heating around the windows. This is the unglamorous bit. Cosy rewards setup work.
Who should avoid Octopus Cosy?
Cosy is not universally a good deal:
- Homes with storage heaters. Storage heaters need Octopus Snug, not Cosy. The two tariffs are designed around different heating patterns and different cheap-rate windows.
- Poorly insulated homes. If the property cools noticeably within an hour or two of the heat pump switching off, the 16:00–19:00 peak becomes either uncomfortable or expensive. In a draughty 1930s semi with single glazing and minimal loft insulation, the heat pump will simply run through peak to keep the house liveable, and the bill follows.
- Households with strong, inflexible evening usage. Cooking, tumble drying, resistive electric heating and other high-load activity between 16:00 and 19:00 is exactly what the tariff penalises. If the family routine is locked in and cannot shift, Cosy is the wrong tool.
- Heat pump owners who cannot or will not adjust their heating schedule. Cosy is not a passive tariff. It pays off only when the heating runs around the windows.
- Homes without a smart meter, or with one not sending half-hourly readings. Without those readings, the tariff cannot function.
- Continuous-running heat pump setups with no realistic way to bias usage. Some older installations or particular control setups simply do not give the homeowner the levers needed.
The honest answer is that Cosy is a tariff with a personality. Match it and you do well. Fight it and you pay for the privilege.
Eligibility and how to switch
To join Cosy Octopus you need:
- An Octopus Energy electricity supply (you can switch to Octopus first if you are not already a customer)
- A SMETS2 smart meter, or a compatible SMETS1 model, set to half-hourly readings
- An eligible heat source: air source, ground source or hybrid heat pump, electric boiler, or electric radiators
The heating system does not need to have been installed by Octopus. Homes part-way through a heat pump installation can still switch. Storage heaters are not eligible.
The switching process for new customers runs in stages. You join Octopus on a standard tariff first while the meter is set up or confirmed and half-hourly readings start flowing. This usually takes around two weeks. Once the data is coming through cleanly, Octopus sends you an email asking you to accept the Cosy Octopus terms, and the move completes.
Under the current 6-month fixed offering, leaving before the end of the term carries a £25 exit fee. If your circumstances change mid-term, for example you sell the property or remove the heat pump, it is worth talking to Octopus directly about how that is handled rather than assuming.
Cosy Octopus vs other Octopus tariffs
Octopus runs several smart tariffs and they are not interchangeable. The short version:
- Octopus Flexible is a single variable rate with no time-of-use structure. A reasonable benchmark to compare Cosy against. If a household cannot or will not shift usage, Flexible is often safer.
- Octopus Snug is the storage heater tariff. Different cheap windows, different control approach (Octopus schedules the heaters via the smart meter), designed for a fundamentally different kind of heating system.
- Octopus Flux was an export-focused tariff for solar and battery households, structured around exporting at peak. It closed to new customers in March 2026. Existing Flux customers may still be on it, but it is no longer a switching option for new joiners.
- Octopus Agile prices electricity half-hourly in line with wholesale costs. Cheaper on average for the right user, but more variable and less heat-pump-shaped than Cosy.
- Intelligent Octopus Go is EV-focused, with a longer overnight cheap window and smart charging integration. Possible to combine with a heat pump, but not built around heat pump load.
A reasonable number of households run Cosy on import alongside Outgoing Octopus on export if they have solar. Cosy is the only Octopus import tariff specifically built around three daily off-peak windows for electric heating.
Quick comparison
| Tariff | Rate structure | Off-peak windows | Peak window | Electric heating required? | Exit fees |
|---|---|---|---|---|---|
| Octopus Cosy (as of 2026) | 3-rate time of use | 04:00–07:00, 13:00–16:00, 22:00–00:00 (8 hrs total, ~51% below day rate) | 16:00–19:00 (~50% above day rate) | Yes (heat pump, electric boiler or electric radiators) | £25 on the current 6-month fixed term |
| Octopus Flexible | Single variable rate | None | None | No | None |
| E.ON Next Pumped (heat pump tariff) | Reduced rate on heat pump usage via separate metering | Heat-pump-specific reduced rate | None in the Cosy sense | Yes (heat pump) | Varies, check current terms |
Rates and structures are accurate as of 2026 and do change. Always check the supplier’s current terms before switching.
Will Octopus Cosy save you money?
The savings depend on three things:
- How much electricity you can shift into the eight Cosy Hours. The more, the better.
- Whether your home can coast through the 16:00–19:00 peak without the heat pump kicking in. This is largely down to your home’s insulation and heat loss.
- How much of your total electricity use is heating, versus general household demand. Cosy rewards heat-pump-heavy homes more than appliance-heavy ones.
Octopus’s own published figures suggest typical savings somewhere in the region of £80–£200 a year for heat pump households on Cosy compared with a flat tariff, depending on usage pattern, region and how aggressively your home shifts usages onto the off-peak periods. Independent estimates land lower in some scenarios, particularly for households that cannot fully avoid peak.
A well-insulated home with a heat pump, hot water cylinder and basic battery storage, run by someone who actually programmes around the windows, will usually do better on Cosy than on Flexible. A draughty home with a heat pump running constantly through peak, in a household with heavy 16:00–19:00 electricity use, can easily end up paying more on Cosy than on Flexible. Both outcomes are real.
For a meaningful estimate, run your own annual kWh figure through Octopus’s calculator for your postcode, then look at how much of that usage you could realistically move. If most of it cannot move, the savings will not either.
FAQ
Do I need a heat pump to get Octopus Cosy?
No, but you do need eligible electric heating. Cosy is open to households with an air source, ground source or hybrid heat pump, an electric boiler, or electric radiators. Storage heaters are not eligible and need Octopus Snug instead.
What are the Cosy Hours on Octopus Cosy?
The three daily Cosy Hours windows are 04:00–07:00, 13:00–16:00, and 22:00–00:00. Eight hours of off-peak electricity in total, currently priced roughly 51% below the standard day rate for your region.
When is the peak rate on Octopus Cosy?
The peak window runs from 16:00 to 19:00 every day. During those three hours, electricity is priced roughly 50% above the day rate.
Is the whole house on the cheap rate during Cosy Hours, or just the heat pump?
The whole house. The Cosy Hours rate applies to all electricity used in the property during those windows, not just the heating system. That is why shifting other loads (washing machine, dishwasher, EV charging, battery charging) into Cosy Hours matters.
Can I get Octopus Cosy with electric radiators or an electric boiler?
Yes. Cosy is open to homes with electric radiators or an electric boiler, as well as heat pumps. The heating system does not need to have been installed by Octopus.
Is Octopus Cosy available for storage heaters?
No. Cosy is specifically not for storage heaters. Storage heater homes should look at Octopus Snug, which is built around overnight charging and an afternoon boost rather than three short daily dips.
Is Cosy Octopus fixed or variable?
As of March 2026, Cosy is offered as a 6-month fixed tariff with a £25 exit fee. Before that change it was a flexible (variable) tariff. The three Cosy Hours windows and the peak window did not change with the move to a fixed structure.
Are there exit fees on Cosy Octopus?
Yes, £25 on the current 6-month fixed term. If you leave the tariff before the term ends, that fee applies. Octopus’s other tariffs (Flexible, Agile, Tracker) do not currently carry exit fees.
Can I be on Cosy Octopus and Outgoing Octopus at the same time?
Yes. Many solar and battery households run Cosy on import and Outgoing Octopus on export. The two tariffs handle different sides of the meter and combine without issue.
Does Cosy Octopus work without a smart meter?
No. You need a SMETS2 smart meter, or a compatible SMETS1 model, set to send half-hourly readings. Without that, the tariff cannot bill the three rate windows correctly.