Octopus Tariffs Compared UK 2026: Agile, Cosy, Go, Tracker

Octopus has more tariffs than any other UK supplier, and the April 2026 rate update reshuffled which one is actually best for which household. This is the side-by-side, with current numbers, gotchas and a clear "which one are you" matcher at the end.

TL;DR — the six-tariff comparison

Octopus Flux closed to new customers in March 2026. Existing customers keep it — treasure it if you have it.

For comparison, the Ofgem April–June 2026 price cap puts electricity at 24.7p/kWh and gas at 5.7p/kWh, with the typical dual-fuel household paying around £1,641 a year. Electricity standing charges rose 2.5p/day; gas standing charges fell 6p/day. Every tariff below should be judged against that 24.7p baseline.

Why "best Octopus tariff" depends on what you own

There is no universal best Octopus tariff. The answer hinges on three things:

1. Do you own controllable kit? An EV, a heat pump, a home battery, smart TRVs, a hot-water cylinder on a timer — anything you can shift in time.
2. Do you export? Solar with or without a battery pulls you toward Outgoing Fixed (or a smart-export tariff if you stay on Flux).
3. Do you have Home Assistant — or any orchestration layer? A half-hourly tariff like Agile rewards orchestration; a flat off-peak tariff like Go rewards a simple timer.

Without controllable kit, the cheapest sensible answer is usually Tracker or staying on a fixed tariff. Add an EV and Intelligent Go starts beating everything. Add a heat pump and Cosy enters the picture. Add a battery and the maths gets dramatic.

Octopus Agile — the half-hourly variable

Agile passes the wholesale market straight through. Each afternoon, usually between 4pm and 8pm, Octopus publishes the unit rates for every half-hour slot of the next day. Cheap overnight slots often land between 5p and 15p; breezy nights drop into negative pricing 30 to 60 times a year, where Octopus pays you to consume. The peak between 4pm and 7pm can hit 70p or more on a still, cold evening. Individual slots are capped at 100p/kWh.

Worked example. A three-bed semi with a dishwasher, washing machine, EV charger and home battery, all orchestrated through Home Assistant, will typically save £150–£250 a year against the Ofgem cap on Agile. Without orchestration — running the same appliances on the same human schedule as before — Agile usually costs more than a flat tariff, because daytime slots routinely run above the cap.

Agile is the right answer if you have shiftable load, an automation layer, and the patience to occasionally see a spiky day. It rewards effort.

Octopus Tracker — the daily wholesale tracker

Tracker sets a single flat unit rate for the whole day, recalculated daily against wholesale. There are no half-hourly windows, no automations, no decisions. You just get a price that — averaged over a year — is usually below the Ofgem cap, often by 10–20%.

Tracker is the right answer for households who want most of Agile's upside without any of its complexity. No heat pump, no battery, no orchestration — just a desire to pay closer to wholesale. The trade-off: you give up the deep cheap slots and the negative pricing, and on a particularly cold or still day the flat rate can climb above the cap — though Tracker's own daily cap is 100p/kWh for electricity and 30p/kWh for gas, so the worst-case is bounded. Less floor, lower ceiling. Tracker is a 12-month commitment with no exit fee, but if you leave you can't re-join for 9 months.

Octopus Go vs Intelligent Go — the two EV tariffs

Go is the original. Four hours of cheap electricity, 00:30 to 04:30, at around 5–7p/kWh depending on your DNO region (the April 2026 update cut Go's off-peak rate by roughly 3.5p across all regions). The rest of the day sits at roughly the Ofgem cap (~24.7p). No smart-charger integration, no bonus slots, no dispatch. You set your EV charger to run between 00:30 and 04:30 and you're done.

Intelligent Go is the upgrade. The base off-peak window stretches from 23:30 to 05:30 — six hours instead of four — at around 5.5p to 8p/kWh depending on your DNO region (north Scotland sits at the bottom of that range, southwest England nearer the top). Octopus also dispatches "bonus" cheap slots during the day when wind generation is plentiful, and integrates directly with supported chargers and cars (Ohme, Hypervolt, most modern Teslas, Polestar, Ford, Hyundai, Kia and others) so your EV simply schedules itself.

The daytime rate on Intelligent Go fell 3.5p in the April 2026 update and now roughly tracks the cap, between 24p and 32p depending on region. That makes Intelligent Go usable for the rest of the house, not just the car.

If you have a supported charger or car, Intelligent Go beats Go almost universally — longer off-peak window, lower off-peak rate, daytime bonus slots. Go is now mostly a legacy product for households whose charger or car isn't on the supported list.

Octopus Cosy — the heat pump tariff

Cosy has three rate bands. Cheap windows of ~14.53p/kWh run 4–7am, 1–4pm and 10pm–midnight — designed around the natural rhythm of a heat pump that wants to pre-warm the house before the cold of evening sets in. The rest of the day sits at a standard ~33.28p/kWh.

Then there is the peak. From 4pm to 7pm, Cosy charges around 51.68p/kWh — the highest peak rate of any UK domestic tariff. Avoiding it is not optional. A heat pump running at full tilt through that window will eat any savings the cheap slots delivered, plus some.

Done well — cheap slots pre-heat the house, peak window the pump idles or runs minimally on stored heat, daytime usage shifts where possible — a typical heat pump household saves £150–£300 a year on Cosy versus the cap. Done badly, you can lose £100 a year compared with a flat tariff. The whole tariff is a bet on your ability (or your automations' ability) to dodge 4–7pm.

Cosy became a 6-month fixed product in March 2026 with a £25 early-exit fee, so the bet is one you make for at least six months at a time.

Octopus Outgoing Fixed — the export side

If you export solar, Outgoing Fixed pays a flat 12p/kWh for every unit you send back to the grid. That dropped from 15p on 1 March 2026, which materially worsened the payback maths for new solar installs but still leaves Octopus near the top of the SEG market — most rival suppliers (E.ON Next, British Gas, EDF) pay 3–7p.

Two practical notes. First, Outgoing Fixed stacks with any import tariff above — Agile, Tracker, Cosy, Intelligent Go all support it as the export half of a dual-tariff setup. Second, if you have a battery and any of the smart import tariffs, the maths often favours using your export rather than selling it — running the house off the battery during the 4–7pm peak typically saves more than the 12p you would have earned exporting it.

Octopus Flux — the legacy mention

Flux closed to new customers in March 2026. If you signed up before then, you have a 4–7pm export rate paid at a premium, a cheap overnight import window, and an expensive peak import — designed so a solar+battery household could charge cheap, discharge into the lucrative 4–7pm export window, and pocket the difference. It was the most profitable tariff ever offered for that specific setup.

If you have it, stay on it. If you don't, the closest equivalent today is a battery sitting on Agile (or Cosy) with Outgoing Fixed for export — less elegant, still workable.

Which one are you?

A short decision tree. Each answer is meant to stand on its own.

You have a heat pump. Go on Cosy — provided you can reliably avoid the 4–7pm peak. If you can't (no battery, no thermal mass, no automation), stay on a flat or tracker tariff and run the pump on a steady schedule.

You have an EV and a supported smart charger or compatible car. Go on Intelligent Go. The 5.5–8p off-peak rate, bonus slots and automatic scheduling beat every alternative.

You have an EV but no supported charger. Go on Go as the simple option, or Agile if you have Home Assistant and want to chase the deeper savings.

You have solar with no battery. Stay on a flat or tracker import tariff and add Outgoing Fixed for export. Half-hourly tariffs add complexity without much upside when you have no way to time-shift consumption.

You have solar plus a home battery. Agile import + Outgoing Fixed export is the standard answer. Charge the battery from cheap overnight slots and your own solar, discharge through the evening peak. Skip exporting at 12p when discharging avoids 30p+ of import.

You have a battery and a heat pump but no solar. Cosy plus battery automation that pre-charges the battery during cheap windows and runs the house off it through 4–7pm. The battery is what makes Cosy safe.

You have no controllable kit at all — no EV, no heat pump, no battery, no solar. Go on Tracker. You'll average below the cap without doing any work. Agile only pays off when you can move load.

You have all of it — EV, heat pump, solar, battery, Home Assistant. Agile import plus Outgoing Fixed export is usually the maximum. Cosy is a credible alternative if the heat pump dominates your load. Run the numbers on your last 12 months of half-hourly data — both Octopus's own comparison tool and the BottlecapDave Home Assistant integration can replay the year for you.

What changes the maths

Three multipliers turn a marginal tariff choice into a clear one.

A heat pump pushes you toward Cosy because the bulk of its load lands in shoulder hours that map onto Cosy's cheap windows — but only if you can dodge the 4–7pm peak. Without that ability, the heat pump pulls you back to Tracker or a fixed tariff.

An EV pushes you toward Intelligent Go. The longer overnight window, the regional 5.5–8p rate, and the bonus slots compound — a typical 8,000-mile-a-year EV saves around £400 a year versus charging at the cap rate.

A battery amplifies whichever tariff you choose. It turns Agile from "save when I happen to be using power cheaply" into "save on every kWh I consume", because you can shift any load to any time. It also makes Cosy genuinely safe by giving you a way to ride out 4–7pm. A 5kWh battery roughly doubles the realised saving of a smart tariff.

Home Assistant is the universal multiplier. Every tariff above gets better with orchestration: dishwashers running in cheap slots, batteries charging on threshold prices, EV chargers responding to dispatch signals, heat pumps backing off through peak windows. The point of an automation layer is that the tariff makes its own savings without you having to think about it.

The verdict

For most habbb-shaped households — some smart kit, a desire to save without micro-managing — the picks are clear. Heat pump? Cosy. EV with a supported charger? Intelligent Go. Battery and orchestration? Agile. No controllable kit? Tracker. Exporting solar? Outgoing Fixed alongside whichever import tariff fits the rest of your house.

The April 2026 rate update made Intelligent Go materially better, made Outgoing Fixed marginally worse, and left Cosy as the highest-stakes tariff on the market — biggest savings for households who can dodge 4–7pm, biggest losses for those who can't.

What undermines any of these picks is the same thing in every case: a tariff that depends on automation, running on a smart home that nobody is keeping working. Cosy without reliable 4–7pm avoidance is a worse tariff than the cap. Agile without orchestration is a worse tariff than Tracker. The tariff is only half the saving; the orchestration is the other half.

That's the part habbb's managed Home Assistant service exists to keep running — the automations, the integration with Octopus, the monitoring, the daily backups, the updates that don't break your battery automation overnight. The boiler-service model: we keep what you have working, so the tariff you picked keeps paying off.

Related reading

• Octopus Agile + Home Assistant — the deep dive on orchestrating Agile
• Save money on energy bills with Home Assistant — the broader pillar
• Home battery payback in the UK — battery economics by tariff
• Heat pump payback in the UK — the Cosy maths in detail
• EV charging with Home Assistant — Intelligent Go orchestration
• Solar panel payback in the UK — export economics and Outgoing Fixed