Last updated: Thursday 17 September 2026 (Europe/London).
Next update: when Octopus reprints Cosy rate cards or changes Cosy Hours windows.
By: Switch Editorial Team, Switch Squid Ltd
Cosy Octopus is Octopus Energy’s heat-pump-oriented time-of-use electricity tariff with three cheap “Cosy Hours” windows every day — 04:00–07:00, 13:00–16:00 and 22:00–00:00 — plus a peak band 16:00–19:00. On Octopus’s own Cosy page (opened 17 September 2026), Cosy Hours are described as about 51% cheaper than the Day rate in your region, and the peak band about 50% above the Day rate. Exact pence per kWh are regional: we will not invent a national unit rate.
I am Switch. This page explains Cosy Octopus heat pump tariff structure, who it suits, and how to compare it with Go / Agile / a plain fix — using Octopus’s published windows and savings illustration, not fabricated p/kWh tiles. Soft context on the energy hub is fine; Compare buttons use the MoneySuperMarket Awin campaign 911601 deepLink.
Cosy Hours at a glance
| Band | Clock (every day) | Octopus framing |
|---|---|---|
| Cosy / off-peak | 04:00–07:00 | ~51% below Day rate (regional) |
| Day / standard | 00:00–04:00, 07:00–13:00, 19:00–22:00 | Regional Day rate baseline |
| Cosy / off-peak | 13:00–16:00 | ~51% below Day rate |
| Peak | 16:00–19:00 | ~50% above Day rate |
| Cosy / off-peak | 22:00–00:00 | ~51% below Day rate |
Source: octopus.energy/smart/cosy-octopus/ (17 Sep 2026). Fixed and flexible Cosy variants exist; flexible tracks Octopus’s flexible regional rates, fixed locks Cosy prices for a term.
Octopus’s own savings illustration
Octopus states you could save around £82 on electricity on fixed Cosy versus their Octopus Fixed tariff for a worked example that assumes 5,877 kWh total (2,700 kWh home + 3,177 kWh heating), based on Cosy customer behaviour. That is an illustration on their page — not your quote. Your heat pump size, weather compensation settings, and how much load you can shift into Cosy Hours dominate the outcome.
Heat pumps, buffers and scheduling
Cosy rewards homes that can pre-heat before the 16:00–19:00 peak and top up in the lunch and late-evening Cosy windows. A weather-compensated heat pump with a water cylinder or highly insulated fabric does this more easily than a poorly insulated terrace that must run hard through peak. If your installer left the pump on a dumb always-on curve, Cosy’s peak band will punish you — fix the schedule before you chase the tariff.
Electric boilers and storage-heavy setups can also sit on Cosy; Octopus markets Cosy for heat pumps and electric boilers. Gas boiler homes usually belong on a dual-fuel or gas-aware comparison instead — see our gas-only maths guide for the October 2026 cap ingredients.
Cosy vs Octopus Go vs Agile
- Cosy: three cheap windows aligned to heat-pump duty cycles; peak 16:00–19:00. Best when heating load is schedulable.
- Go / Intelligent Go: EV-led overnight cheap windows (different product family). Great for cars; not automatically best for heat pumps.
- Agile: half-hourly wholesale-linked prices. Highest skill ceiling; can spike. Only for households that watch the app.
We are not printing invented p/kWh for Go or Agile here. Open Octopus’s tariff pages for your postcode, or run a regulated comparison, then verify on octopus.energy before you switch.
Standing charges still matter
Time-of-use unit rates grab the headlines; standing charge still accrues daily. A low-use flat with a heat pump for a single room can see standing dominate. Pull 12 months of kWh (or a heat-loss survey estimate) before you celebrate Cosy Hours percentages.
VAT and price-cap context for standard variable tariffs still frame the wider market — Cosy is an Octopus product outside a single national “cap unit rate” slogan. Compare like-for-like annualised £ for your usage shape.
Eligibility and smart meter practicalities
Cosy expects a smart meter journey Octopus can settle on half-hourly-style data. If your meter appointment is months out, ask Octopus about interim options before you dismantle a decent fix. Export tariffs (Outgoing / Flux) are separate products if you have solar — do not assume Cosy import rates equal export rates.
When Cosy is the wrong answer
If you cannot shift load out of 16:00–19:00 (for example a heat pump that must run flat-out on a cold snap with no buffer), Cosy’s peak uplift can erase Cosy Hours gains. If you are on a cheap long fix with exit fees larger than any Cosy saving, run the numbers including exit. If you are about to move house, a flexible Cosy may beat a new fixed Cosy term.
How SwitchSquid treats energy CTAs
Home energy Compare buttons use MoneySuperMarket’s Awin 911601 affiliate URL. That is not SwitchSquid’s own quote form. Business energy uses /business-energy/ only.
Cold snaps and the peak trap
UK cold snaps drive heat pumps hardest between late afternoon and evening — exactly when Cosy’s peak band sits. A well-sized pump with weather compensation can pre-heat the fabric and emitter circuit in the 13:00–16:00 Cosy window, then coast. An undersized pump will thrash through peak regardless of tariff cleverness. Tariff choice does not fix a heat-loss mis-sell.
Keep a simple diary for one winter week: note indoor setpoints, outdoor temperature, and whether the pump ran in peak. If more than a third of heating kWh lands in 16:00–19:00, model Cosy carefully against a flat single-rate fix before you switch.
Solar, batteries and Cosy stacking
Solar export products (Outgoing Lite, Flux, Intelligent Flux) are separate from Cosy import. Midday Cosy Hours (13:00–16:00) can overlap with solar production — which means you may not need to import during that window at all on bright days. Batteries complicate the story further: charging from Cosy Hours overnight and discharging through peak can amplify savings, but only with correct inverter schedules and Octopus product compatibility.
Do not assume a battery auto-magically “does Cosy”. Commission the schedule, then verify on the half-hourly consumption graph in your Octopus app for a fortnight.
Switching process and exit fees
Moving to Cosy from another supplier follows the usual electricity switch timeline. Leaving a fixed tariff early can trigger exit fees that dwarf a winter of Cosy gains — read the losing contract. Within Octopus, moving between Octopus products is often smoother but still needs a clear start date aligned to your meter read / smart schedule.
Keep Warm Home Discount and any vulnerability support flags updated when you switch; tariff choice should not silently drop you from support schemes you still qualify for.
Worked thinking without invented pence
Suppose your heat pump uses roughly 3,000 kWh a year for heat and your home uses 2,700 kWh for everything else — in the ballpark of Octopus’s public example. If you can place half of the heating kWh inside Cosy Hours and keep peak-band heating under 15% of heating kWh, Cosy’s percentage offsets versus Day rate start to look attractive versus a flat fix. If peak-band heating is 40% of heating kWh, stop and fix controls first.
Export your half-hourly CSV from the Octopus app after two weeks on Cosy (or ask for a trial path). Re-run the split. Tariff blogs that print a single “Cosy = 12p” national figure without a region are guessing — we refuse to do that on SwitchSquid.
Finally, treat Cosy as a heating-operations product as much as an energy product. The households who win are the ones who change schedules, not the ones who only change supplier logos on a bill PDF.
If your installer offers a post-occupancy optimisation visit, take it before or just after you land on Cosy — emitter balancing and weather-curve tweaks often free more pounds than a 1p unit-rate argument on social media.
Bookmark Octopus’s Cosy page and re-check windows if you hear of a product refresh — the three Cosy Hours pattern has been stable, but marketing savings figures move when Fixed and flexible baselines move.
FAQ
What are Cosy Octopus hours?
04:00–07:00, 13:00–16:00 and 22:00–00:00 every day, per Octopus’s Cosy page, with peak 16:00–19:00.
How many pence per kWh is Cosy?
Regional — Octopus does not publish one national figure on the Cosy marketing page. Check your postcode in the Octopus account/sign-up journey.
Is Cosy only for heat pumps?
Octopus markets it for heat pumps and electric boilers; suitability depends on whether you can use Cosy Hours.
Fixed or flexible Cosy?
Fixed locks prices for a term; flexible can move with Octopus flexible rates. Prefer certainty vs possible wholesale moves accordingly.
Will I save £82?
That is Octopus’s illustrative figure for a stated 5,877 kWh profile versus Octopus Fixed — not a guarantee for your home.
Cosy or Agile for a heat pump?
Cosy if you want predictable windows; Agile if you actively manage half-hourly prices. Many households prefer Cosy’s simpler shape.
Do I need a smart meter?
Practically yes for a modern Octopus TOU product — confirm with Octopus for your MPAN.
Where should I compare?
Regulated comparison via our MSM Awin link, then verify on octopus.energy.
Regional rates change. Affiliate links may earn SwitchSquid a commission at no extra cost to you.
