Heat pump electricity tariffs in the UK, checked at source

A gas boiler and a heat pump both keep a house warm, but they draw on different meters. Replace the boiler and a large part of the household bill moves from the gas account to the electricity account. Electricity costs considerably more per unit than gas, so the terms of your electricity tariff now govern a much bigger share of what you pay.

That is the whole idea behind a heat pump tariff. A heat pump does not need heat at the exact moment you ask for it. A well insulated house holds warmth for hours, and a hot water cylinder holds it for longer. So the supplier offers cheaper electricity during hours when the grid has spare capacity, on the understanding that you will run the pump mainly then.

The trade is not free. Some suppliers pay for those cheap hours by charging more at peak. That is the single most important thing to understand before choosing, and it is the thing comparison tables tend to flatten into one “discount” figure.

Three rates rather than two. Cosy hours run 04:00–07:00, 13:00–16:00 and 22:00–00:00 — eight hours a day — priced at 51 per cent below the regional day rate. Octopus funds this with a peak rate 50 per cent above the day rate between 16:00 and 19:00.

Eligibility covers a heat pump, an electric boiler or electric radiators, and Octopus states the equipment does not have to have been installed by them. You need a SMETS2 meter, or a SMETS1 meter on the Secure network. There are fixed and flexible versions, and no exit fees.

Octopus quotes a saving of £82 a year, calculated on a household using 5,877 kWh.

Source: octopus.energy/smart/cosy-octopus

Also three rates, with a longer cheap window. Super off-peak runs 22:00–06:00, off-peak covers 06:00–16:00 and 19:00–22:00, and peak is 16:00–19:00. Like Octopus, the peak band exists to pay for the cheap one.

It is a 12 month fixed tariff with no exit fees. Eligibility is a heat pump or electric boiler, and notably E.ON Next accepts customers who are “planning to have one installed”, not only those who already have one. It is not available on Smart Pay As You Go.

E.ON Next quotes £187.85, assuming usage split 21 per cent super off-peak, 60 per cent off-peak, 19 per cent peak, compared against 26.11p per kWh from 1 July 2026. The version we read was Next Pumped Fixed 12m V13.

Source: eonnext.com/tariffs/next-pumped

Structurally the simplest, and the only one of the five with no peak rate at all. EDF takes 10p per kWh off the regional standard rate during 04:00–07:00 and 13:00–16:00, six hours a day. Outside those hours you pay the ordinary rate. The standing charge is unchanged.

The rate tracks the Ofgem price cap quarterly, so the underlying price moves, but the 10p discount itself is fixed. Any make of heat pump qualifies, and unlike E.ON Next the pump must already be installed.

EDF quotes £146 on the tariff page. ⚠ The page’s own metadata says “up to £164”. We could not reconcile the two figures and are reporting both rather than picking one.

Source: edfenergy.com/heating/electric/air-source-heat-pump/tariffs

The widest cheap window of the five, and the only one that is not a rate change.

British Gas gives half price electricity from 13:00–16:00 and 00:00–07:00. That is ten hours a day, 70 hours a week, well ahead of the others. But the discount does not appear at the meter. You are billed at the full rate and then receive a weekly “Heat Power Credit” on your account. The standing charge is paid in full.

Eligibility is the broadest here: a heat pump, electric heating, an electric vehicle or a home storage battery. It is a fixed tariff, and credit payment only — prepayment meters are excluded. A smart meter that sends no reading for 30 days moves you to the standard variable tariff.

⚠ Signing up removes you from PeakSave. If you currently take part in that scheme, this is a swap, not an addition. British Gas quotes assume around 35 per cent of usage falls in the cheap hours.

Source: britishgas.co.uk/energy/heat-pump-tariff.html

🔴 Clause 5 of ScottishPower’s own terms and conditions states: the tariff ends on 30 April 2026. That date has passed.

While it ran, clause 13 set peak at 16:00–10:59 and off-peak at 11:00–15:59 — a five hour cheap window, the narrowest of the five, and by far the widest peak. Clause 4 restricted it to existing ScottishPower customers, paying by Direct Debit, who consent to half hourly meter readings.

We are leaving it on this page because it is still listed as a live option on comparison sites. If you are reading a table that offers it, that table has not been checked against the supplier.

1. Whether there is a peak penalty. Octopus and E.ON Next both charge more between 16:00 and 19:00. EDF does not. British Gas does not state one. If your household cooks, showers and runs appliances in the early evening and cannot move that, a tariff with a peak band can hand back the discount you came for. If you can shift, the peak tariffs offer a deeper cut in the cheap hours.

2. Whether the discount reaches your meter or your bill. Four of the five change the price of a unit. British Gas does not — it charges the full price and credits you afterwards. The end result may be similar, but the cash flow is not, and neither is the standing charge treatment.

3. When the cheap hours fall. These windows are genuinely different, not variations on a theme:

• Octopus: 04:00–07:00, 13:00–16:00, 22:00–00:00 — 8 hours
• E.ON Next: 22:00–06:00 cheapest, plus a wide off-peak band
• EDF: 04:00–07:00, 13:00–16:00 — 6 hours
• British Gas: 00:00–07:00, 13:00–16:00 — 10 hours

A heat pump paired with a hot water cylinder can use an overnight block well. A heat-only system in a poorly insulated house may need the afternoon slot more. The right window depends on the building, not on the size of the discount.

You will find pages listing these tariffs at a single rate. We will not, and the reason is not caution for its own sake.

These rates are regional. Octopus and EDF both price against a regional standard rate, so the same tariff costs a different amount in Merseyside than in the South West. They also move quarterly with the Ofgem cap. A figure typed onto a web page in August is wrong by October, and the page rarely says so.

What we publish instead is the structure: the hours, the mechanism, the eligibility rule and the trade-off. Structure changes when the supplier redesigns the tariff, which is rare, and we can honestly maintain it. For the current price, use the supplier’s own quote tool with your postcode — it is the only figure that applies to you.

Set the four headline claims side by side and the problem is obvious:

• Octopus £82 — on 5,877 kWh a year
• E.ON Next £187.85 — on a 21 / 60 / 19 per cent split across three bands
• EDF £146 — modelling a specific heat pump efficiency, with £164 in the page metadata
• British Gas — no single figure, quotes assume about 35 per cent off-peak usage

Every number is calculated against a different household, a different consumption, and a different assumption about how much you can shift. Ranking them produces a league table of assumptions, not of tariffs. The E.ON Next figure is more than twice the Octopus one, and that tells you almost nothing about which would be cheaper for you.

🔑 The number that matters is the one you get from putting your postcode and your usage into each supplier’s quote tool.

Comparison sites are listing a tariff that has ended. ScottishPower’s terms document is unambiguous and the date passed months ago, yet the tariff still appears in third party tables. That is a useful test to apply to any energy comparison you read: does the source document agree?

Old EDF tariff pages are still live. Several earlier EDF heat pump tariff URLs still load normally, and are still indexable, although only one tariff is now linked from the hub page. A search engine can surface a page that the supplier no longer offers. Nothing dishonest is happening — pages simply outlive products — but it means arriving at a supplier page by search is not the same as reading their current range.

Do I have to be on one of these? No. A heat pump runs on any tariff. These exist because the alternative — running a heat pump on a flat standard rate — gives away a large part of the running cost advantage the pump was installed for.

Can I switch to one before the pump is installed? It depends on the supplier, and this is a real difference. E.ON Next accepts customers planning an installation. EDF requires the pump to already be in place. Octopus states the equipment need not have been installed by them, which is a separate question from whether it must exist yet.

Do I need a smart meter? Yes, in every case. Time of use pricing requires half hourly readings. Octopus specifies SMETS2 or SMETS1 on the Secure network. British Gas moves you off the tariff if the meter stops reporting for 30 days.

What if I have a prepayment meter? British Gas Heat Power excludes prepayment. E.ON Next excludes Smart Pay As You Go. Check before assuming a tariff is open to you.