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Cosy Octopus is an electricity tariff designed for homes using a heat pump, electric boiler or electric radiators. It offers three cheaper periods each day, alongside a more expensive evening peak, encouraging households to warm the building and hot water when electricity costs less. This guide was checked on 10 July 2026. Rates vary by postcode and tariff version, so the quotation shown in an Octopus account is the figure that matters.
Cosy Octopus has three prices during the day. The cheapest price applies during three separate Cosy periods. A standard day rate applies for most remaining hours, while a higher peak rate applies during the busiest part of the evening. The cheap periods run from 4am until 7am, 1pm until 4pm and 10pm until midnight. Together they provide eight hours of cheaper electricity every day. The peak period runs from 4pm until 7pm. The published periods remain the same when clocks change between Greenwich Mean Time and British Summer Time. Octopus warns that some in home displays can show misleading times, so customers should rely on their bill, account or Octopus app when checking charges. Octopus states that each Cosy period is priced 51 per cent below the regional day rate. The peak rate is 50 per cent above that day rate. The exact pence per kilowatt hour figures depend on the customer's electricity region and current tariff quotation. All electricity used in the property follows these time bands. The cheaper rate is not restricted to the heating system. A dishwasher, washing machine, immersion heater or home battery can also use the Cosy price when safely scheduled inside those periods.
A heat pump normally works best when it maintains a steady indoor temperature rather than repeatedly heating a cold building in short, intense bursts. Cosy Octopus does not require the heat pump to remain off between cheap periods. Instead, it gives the household an incentive to move a larger share of heating into times when the rate is lower. A suitable schedule might slightly raise the target temperature during cheap hours and reduce it during the peak. The building then acts as a modest heat store. Good insulation, correctly sized radiators and sensible flow temperatures help the property retain that warmth.
Electricity used between 4pm and 7pm costs more than the standard day rate. This is often when national demand rises as people return home, cook and use appliances. A home that continues running its heat pump heavily throughout this window may lose much of the benefit created by the cheap periods. Comfort should remain the priority. The better approach is to prepare the home before 4pm, reduce avoidable demand during the peak, then resume normal heating afterwards.
Octopus offers fixed and flexible versions of Cosy. On the fixed version, the quoted day rate, Cosy rate, peak rate and standing charge remain fixed for the stated tariff term. On the flexible version, rates and standing charges can change. Octopus explains that flexible Cosy prices are calculated as a percentage of the relevant Flexible Octopus rate in the customer's area. The supplier must give reasonable notice when those prices change. Neither version has an exit fee. Customers can move to another Octopus tariff or change supplier without paying a leaving charge. A fixed tariff still does not fix the total bill because the amount paid depends on actual consumption.
Cosy Octopus is available to homes with an operational heat pump or another heating system accepted by Octopus. The public eligibility information includes air source heat pumps, ground source heat pumps, electric boilers and electric radiators. The household must first be supplied by Octopus Energy. It also needs a compatible smart meter capable of providing half hourly readings. Octopus says it can connect to second generation smart meters and certain first generation Secure meters. A new customer may initially join a standard tariff while Octopus connects to the meter. Octopus says this connection process generally takes around fourteen days.
Cosy is an electricity only tariff. A household retaining gas will need a separate gas tariff. Cosy can be paired with Outgoing Octopus, Agile Outgoing Octopus or the Octopus Smart Export Guarantee. A home battery can charge during Cosy periods and support the property during the evening peak.
The Ofgem price cap from 1 July to 30 September 2026 uses an average electricity rate of 26.11 pence per kilowatt hour and an average daily standing charge of 57.19 pence for a Direct Debit customer. A household with an electric vehicle may find Intelligent Octopus Go more valuable because it provides a long overnight cheap period and managed car charging. A home with substantial solar generation and battery storage may prefer Octopus Flux or another import and export combination. The right comparison uses actual half hourly consumption where available. Apply each Cosy rate to the electricity used in its matching period, add the standing charge, then compare the result with alternative tariffs across a realistic heating season.
Cosy Octopus is strongest where a well designed heat pump system can shift meaningful demand into the three cheap periods without sacrificing comfort. Homes with thermal mass, good controls and occupants willing to adjust schedules are especially well placed. Octopus reports that Cosy customers with its heat pumps saved an average of ยฃ200 over the year to 1 July 2026 compared with producing the same heat using an 85 per cent efficient gas boiler on Flexible Octopus. That is historical fleet data, not a promise for every home. Cosy Octopus can lower heating costs, but the tariff cannot correct poor insulation, unsuitable emitters or inefficient control settings. Its value comes from combining sound heat pump design with practical scheduling and a careful comparison using the property's own energy data.
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