Tariff guide

Cosy Octopus is built for homes that heat mainly with electricity, especially heat pumps, electric boilers and electric radiators. It gives you cheaper electricity in three daily windows so you can warm the home, heat water or run flexible appliances away from the evening peak.

It is not automatically the best tariff for every heat pump home. The useful question is whether your heating setup, insulation and daily routine let you move enough demand into the cheap periods without making the house uncomfortable.

How Cosy works

Cosy has three rate bands each day:

• Cosy Hours: 04:00-07:00, 13:00-16:00 and 22:00-00:00. That gives eight hours of cheaper electricity spread across the day.
• Day rate: the remaining standard-rate periods outside Cosy Hours and the evening peak.
• Peak rate: 16:00-19:00, when electricity is more expensive.

Octopus describes the cheap windows as 51% below the regional day rate and the peak as 50% above it. Treat those percentages as a structure, not a single national price. Your actual unit rates and standing charge depend on your region, postcode and the tariff version offered when you join.

Smart-tariff billing also depends on Octopus getting compatible half-hourly smart-meter readings. Thermostat, heat-pump controller, inverter or home-automation data can help you understand your routine, but it is not the final billing record if Octopus meter data later disagrees.

For the latest regional prices, use Octopus's own Cosy Octopus page or compare your postcode on the Switch to Octopus tariff comparison tool.

Why the windows matter

The early morning window can pre-warm the house before the day rate starts. The afternoon window can top up heat before the 16:00-19:00 peak. The late evening window gives you another lower-cost period before bedtime.

That pattern works best when the home can hold heat for a while. If the property cools quickly, or the heat pump has to work hard during the evening peak, the cheap windows may not make up for the higher peak period.

Who Cosy can suit

• Heat pump homes with decent thermal comfort. If you can pre-heat gently and avoid big evening boosts, Cosy is worth checking.
• Homes with electric boilers or electric radiators. Octopus includes these in the Cosy eligibility framing, subject to its checks.
• Households with flexible daytime use. Laundry, dishwashers, water heating and battery charging may fit the 13:00-16:00 or 22:00-00:00 windows.

What to check first

• Smart meter readiness. Cosy needs half-hourly smart meter readings. Octopus says setup can take time after a switch, meter install or meter handover.
• Heating controls. Make sure your heat pump, electric boiler, radiator schedule or home battery automation is not fighting the Cosy windows. A saved schedule that looks cheap in an app still needs to match the smart-meter periods Octopus bills.
• Your evening demand. Cooking, showers, heating boosts and EV charging in the 16:00-19:00 window can weaken the case for Cosy.
• Other smart tariffs. If you also have an EV, solar or a home battery, compare Cosy against Go, Intelligent Go, Agile and export options rather than looking at heating alone.
• Current terms. Check whether the offer shown to you is fixed or variable, how long it lasts and whether an exit fee applies.

Bottom line

Cosy Octopus is a sensible tariff to investigate if your home is mainly heated by electricity and you can shift heating into three lower-cost windows. It is less compelling if your peak-time use is high, your home loses heat quickly or another smart tariff better matches your EV, solar or battery setup.