A heat pump tariff is a time-of-use electricity contract that gives the homeowner discounted unit rates during off-peak windows, on the design assumption that the heat pump will pre-heat the home or top up the hot water cylinder when electricity is cheap and coast through peak periods. Octopus Cosy delivers three cheap windows per day, OVO Heat Pump Plus delivers a fixed off-peak window, and E.ON Next Drive blends EV and heat pump time-of-use into one product. The catch is that none of these tariffs work without a working SMETS2 smart meter and proof of MCS heat pump installation.
Last reviewed: May 2026
TL;DR
- Octopus Cosy offers three off-peak windows per day (early morning, lunchtime, early evening), shaped to match heat pump duty cycles.
- OVO Heat Pump Plus pairs a single off-peak window with manufacturer-tied install partnerships.
- E.ON Next Drive is an EV tariff that some heat pump owners use as a hybrid load tariff; E.ON Next Pulse historically targeted heat pump only.
- British Gas does not currently offer a dedicated heat pump tariff in 2026; standard variable applies.
- All heat pump tariffs require SMETS2 smart meter, half-hourly settlement and MCS installation evidence.
What a heat pump tariff actually is
A heat pump tariff is an Ofgem-regulated retail electricity contract structured around the load profile of a domestic heat pump. The economics work in three layers. First, the supplier sees a customer whose annual electricity consumption is materially higher than a non-heat-pump household, typically 4,000 to 6,000 kWh of additional load. Second, the supplier can shape when that load lands using time-of-use pricing, which lowers their wholesale exposure during peak periods. Third, the customer benefits from a unit rate during off-peak windows that is sometimes a half or a third of peak.
Every UK heat pump tariff in 2026 sits on the same regulatory base: half-hourly settlement, smart meter required, dynamic time-of-use signals derived from the wholesale day-ahead market or fixed by the supplier's tariff design.
The tariff landscape, supplier by supplier
The table below summarises the structural differences across the main heat pump tariffs available to UK customers in May 2026. Live unit rates change frequently; verify the current rate on the supplier's tariff page before signing.
| Supplier | Tariff | Cheap windows per day | Smart meter required | MCS proof required | Exit fees |
|---|---|---|---|---|---|
| Octopus Energy | Cosy Octopus | Three (early morning, lunchtime, pre-peak evening) | SMETS2 yes | Yes | None typical |
| Octopus Energy | Octopus Tracker | Daily wholesale-linked rate, no fixed window | SMETS2 yes | Not for Tracker but eligibility checks apply | None |
| OVO Energy | OVO Heat Pump Plus | One fixed off-peak window | SMETS2 yes | Yes, MCS install evidence | Verify on tariff page |
| E.ON Next | E.ON Next Drive | One overnight window (designed for EV, used by some hybrid users) | SMETS2 yes | Not specifically | None typical |
| E.ON Next | E.ON Next Pulse (historic) | Off-peak window structured for heat pump | SMETS2 yes | Yes | Verify on tariff page |
| British Gas | No dedicated heat pump tariff | Standard variable applies | SMETS2 useful but not required | n/a | n/a |
Verify the live unit rate on the supplier's tariff page before any decision: published peak, off-peak and where applicable super-off-peak rates change with Ofgem cap movements (the quarterly cap decisions in April, July, October and January) and with supplier commercial discretion above the cap.
Octopus Cosy: why three windows matter
Cosy's defining design choice is three cheap windows per day rather than one overnight window. A typical Cosy schedule has cheap rate roughly 04:00 to 07:00, 13:00 to 16:00, and 22:00 to midnight, with a peak window in the early evening when grid demand spikes.
Three windows align with heat pump physics. A heat pump rarely benefits from a single overnight charge in the way an EV does. Heat fades faster than charge in a battery: a home brought to 22°C at 06:00 will be back at 18°C by 19:00 in a cold January, so a midday top-up matters. The lunchtime cheap window lets the heat pump push the cylinder to 50°C ready for evening hot water demand, and gives radiators a midday boost so the home is not relying on the expensive evening peak. On Cosy's published structure, the peak rate is materially above the standard variable rate and the off-peak rate is materially below it. The arithmetic works only if the heat pump's controller and the homeowner's behaviour actually shift load into the cheap windows. Octopus published time-of-use commentary across 2024 and 2025 noting that Cosy customers averaged roughly 60 to 70% of heat pump consumption in cheap-rate windows where the system was correctly configured.
OVO Heat Pump Plus: the bundled play
OVO Heat Pump Plus is a tariff product OVO launched with named manufacturer partnerships, where the heat pump unit and the tariff are co-marketed. The cheap window structure is a single fixed off-peak block, simpler than Cosy's three-window approach.
The benefit of OVO's product is simplicity: one window, easy to schedule, predictable bills. The trade-off is less flexibility for hot water duty during midday or evening. OVO's eligibility check requires MCS installation evidence and a working SMETS2 smart meter on half-hourly settlement.
E.ON Next Drive and the hybrid load question
E.ON Next Drive is positioned as an EV tariff, with an overnight cheap window of typically seven hours at a deeply discounted rate. Heat pump owners with an EV often run on Next Drive because the overnight window covers both the EV charge and the heat pump's overnight setback recovery. E.ON Next Pulse historically targeted heat-pump-only customers, with similar structural mechanics but without the EV framing.
Here is where it breaks for a heat-pump-only Next Drive customer: the seven-hour overnight window is generous, but it does not catch midday hot water demand. Cosy's three-window design covers that gap where Next Drive does not. The right choice depends on whether the household also has an EV.
British Gas and the absence of a dedicated tariff
British Gas, the largest UK retail energy supplier by customer count, has not launched a dedicated heat pump tariff equivalent to Cosy or Heat Pump Plus as of May 2026. British Gas heat pump customers default to standard variable or one of the company's fixed deals. The result is that British Gas heat pump owners typically pay close to the Ofgem cap unit rate on all their heat pump consumption, with no off-peak window to shift load into.
This is one of the cleaner cases in UK retail energy where supplier choice changes the running-cost economics by a material margin. Ofgem's April 2026 default tariff cap decision sets the cap unit rate at the level used in most British Gas variable products; the savings from moving to Cosy or Heat Pump Plus depend almost entirely on the off-peak unit rate spread.
How to calculate the running cost difference
Take a typical UK heat pump home: 9,000 kWh of annual heat demand at SCOP 3.3, giving 2,727 kWh of electricity consumption attributable to heating, plus 1,200 kWh for hot water at SCOP 2.8, giving 429 kWh. Add 3,500 kWh of base household electricity. Total: roughly 6,656 kWh per year.
On a flat standard variable tariff at, say, 28p per kWh, the annual bill is roughly £1,864. On a Cosy schedule where 65% of heat pump consumption lands in cheap-rate windows at 14p and 35% lands at peak rates of 38p, and base load splits 50/50 across the windows, the same kWh total can come out around £200 to £350 lower depending on the exact peak/off-peak spread that quarter. Verify the live rates on the supplier's tariff page.
The takeaway is that time-of-use tariffs only deliver savings if load actually shifts. A heat pump controller without smart scheduling, running on a default thermostat, will burn its kWh whenever the home calls for heat, regardless of the tariff.
Regional and devolved-nation notes
Standing charges and unit rate spreads vary across the 14 Ofgem regions. London standing charges are typically the highest; Northern Scotland (in the Hydro Board region) has its own structural premium. North Wales and Merseyside (the Manweb region) carries one of the higher rural standing charges. These differences are baked into the regional Ofgem cap published every quarter.
For heat pump tariffs specifically, all five major suppliers offer national pricing for the unit rates, but the standing charge component remains regionalised. A heat pump owner in Aberdeen on Cosy will see the same off-peak unit rate as one in Birmingham but pay a different standing charge based on local network costs.
Scotland and Northern Ireland operate on the same GB tariff framework for Octopus, OVO and E.ON Next, with Northern Ireland Electricity operating as a separate domain. Northern Ireland heat pump customers cannot access GB heat pump tariffs and instead route through Power NI or Click Energy.
Exit fees and contract length
Time-of-use heat pump tariffs in the UK typically run as variable products without long fixed terms, so exit fees are minimal or absent at the time of writing. Some suppliers (notably OVO with certain fixed heat pump tariff variants) carry exit fees of around £30 to £75 per fuel where the customer leaves before the end of the fix. Octopus has historically operated without exit fees on Cosy.
The implication for switchers is that moving from British Gas standard variable to Octopus Cosy is typically frictionless, with no exit penalty and a switch completing inside Ofgem's 17-day switching window under the Faster Switching Programme rules.
The honest summary on choice
Cosy suits households where the heat pump controller is smart enough to use three windows and where someone is willing to set up timer schedules. Heat Pump Plus suits households who want simplicity and predictable pricing. Next Drive suits households running both an EV and a heat pump on the same supply. British Gas customers without a dedicated tariff are likely paying more than they need to. On the ground, the limiting factor on real-world savings is the heat pump controller and the homeowner's willingness to schedule, not the headline unit rate.
Frequently asked questions
Is a smart meter needed for a heat pump tariff?
Yes. Every heat pump tariff in the UK requires a working SMETS2 smart meter on half-hourly settlement. SMETS1 meters often need replacing or remote upgrade before signing.
Will switching to Cosy save money automatically?
Not automatically. Savings depend on shifting heat pump load into the cheap windows. A heat pump running on a basic thermostat without scheduling can pay more on Cosy than on a flat tariff if most heat is called for during peak hours.
Can a customer be on a heat pump tariff without owning a heat pump?
OVO Heat Pump Plus requires MCS installation evidence. Octopus Cosy has historically been open to other low-carbon-heating customers but eligibility rules change; verify on the supplier's tariff page.
Are heat pump tariffs available in Northern Ireland?
Not in the GB form. Northern Ireland Electricity is a separate domain. Heat pump customers in Belfast and across the province route through Power NI or Click Energy, with different tariff structures.
What happens if the supplier withdraws the tariff?
Suppliers can close tariffs to new customers but existing customers are typically grandfathered until contract end. Ofgem's licence conditions protect against retrospective unit rate changes outside the price cap regime for fixed-term products.
Can an EV tariff and a heat pump tariff run at the same address?
Some suppliers offer combined products (E.ON Next Drive being the clearest example). Most households cannot stack two separate time-of-use tariffs at the same MPAN.