TL;DR
- Octopus Tracker sets a fresh electricity and gas unit rate every day, linked to wholesale market prices, with a contractual maximum that protects against runaway spikes.
- Most days during 2025 it sat below the Ofgem cap. On the coldest still days of February 2025 it ran into the daily cap for a short stretch, which is normal behaviour for the product.
- Tracker is single-rate. Unlike Agile, there are no half-hourly bands. Customers pay the same per-kWh price across all 24 hours of a given day.
- A smart meter is required, but the load shifting that helps on Agile does not help on Tracker. The saving is structural, not behavioural.
- It is best for households happy to glance at the next-day price each evening and absorb a wider price range than a fixed tariff would deliver.
Last reviewed: May 2026
Tracker is the simplest of the Octopus smart tariffs to explain and the hardest one to misjudge. Prices change once a day. Wholesale market movements drive most of the variation. A contractual cap protects against the worst spikes. The trade-off is that there is no behavioural lever for customers to pull. Whatever the wholesale market does, that is the day's price.
For a household used to a fixed tariff, that is unsettling at first.
How the daily price is set
Each evening, Octopus publishes the next day's Tracker unit rates. The calculation uses wholesale electricity and gas market data, network charges, policy costs, supplier margin, and VAT. The number lands by about 10pm. The new rate applies from midnight to midnight the following day.
This is a structural difference from the Ofgem default tariff cap, which is recalculated every three months. Tracker passes through the day-to-day movement that the cap smooths out. In a falling wholesale market, Tracker drops faster than the cap. In a rising wholesale market, Tracker climbs faster too.
The catch is what happens at the extreme. Octopus's Tracker contract specifies a per-day maximum for both electricity and gas. For the 2025-26 winter, that ceiling has sat around 100p per kWh for electricity and 30p per kWh for gas, well above any actual day-rate that triggered during the year. The cap exists because wholesale markets have, in living memory, gone parabolic; it is the seatbelt, not the cruise control.
The volatility is the price of the structural saving.
What 2025 actually looked like
The retail Tracker history through 2025, published on the Octopus customer portal, gives an idea of typical movement. Electricity unit rates ranged from around 18p per kWh on mild windy days to 39p per kWh on the coldest February evenings. Gas ranged from around 5p per kWh in spring to a brief 28p run during the February cold snap, when wholesale TTF spiked. The annual mean for a typical household, weighted by consumption, came in roughly 10% below the Ofgem default cap for that period.
That 10% figure is the headline that most independent reviewers have settled on. It is not guaranteed for 2026. The relationship between Tracker and the cap depends entirely on where wholesale sits and where the cap is set; the two move on different cadences.
For comparison: the Ofgem cap unit rate for electricity over the same year, set by the Ofgem default tariff cap announcement series of 28 May 2025 and 22 November 2025, sat in a tight range around 26 to 28 pence per kWh. Tracker spent most days below that band.
Where the headline saving comes from
Two things drive the structural saving. First, the cap formula bakes in a forward-hedge cost: suppliers must hedge volumes for the cap period, and hedging is not free. Tracker has no hedge; the wholesale price flows through directly. Second, the cap is reset every three months only. In a falling market, that delay costs cap customers money. Tracker customers see the fall the next day.
The flip side is symmetrical. In a rising market, cap customers benefit from the lag. Tracker customers pay the rise immediately.
In practice, over a multi-quarter window the structural saving has been real but variable. Some months it is 15%. Some months it is 3%. A handful of months in late 2022 and early 2023, before the contractual cap was raised, Tracker actually breached its prior ceiling and Octopus had to absorb the spread or trigger the cap. The post-2023 rebuild of the Tracker cap formula corrected that.
Comparison with Agile and the standard variable
Octopus has three primary smart tariffs that compete with each other for similar households. The choice tree usually runs through this short comparison.
| Feature | Tracker | Agile | Flexible Octopus (standard variable) |
|---|---|---|---|
| Pricing cadence | Daily | Half-hourly | Quarterly (linked to cap) |
| Smart meter required | Yes | Yes | No |
| Behavioural lever | None | Strong | Limited |
| Daily price ceiling | Yes (contractual) | No fixed ceiling | Cap applies |
| Best fit | Steady consumer | Flexible consumer with batteries or EV | Set-and-forget household |
Tracker is the right tariff for the household that wants a structural saving without doing any work. It is not the right tariff for someone who can run a tumble dryer at 3am to chase a cheap half-hour band.
How the gas Tracker behaves differently
Gas Tracker uses the same daily-price mechanic but reflects the Title Transfer Facility (TTF) day-ahead market rather than the GB power day-ahead. TTF spikes faster and bigger than power markets when European storage is tight or pipeline supply is disrupted. The 2022 invasion of Ukraine and the September 2022 Nord Stream sabotage were the recent reference points; both pushed TTF well past 300 EUR per MWh, with gas Tracker daily-cap territory hit briefly.
For 2026 the day-ahead has been calmer. Gas Tracker has run mostly between 5p and 9p per kWh through Q1 2026, against a cap unit rate of 7.01p set in the Ofgem Q1 2026 cap announcement. A household with a high gas burn (poorly insulated, large) sees more variation in absolute terms than a small-consumption household.
Where it breaks: a multi-day cold spell with low wind. Power Tracker climbs because gas-fired generation drives the marginal cost of electricity. Gas Tracker climbs in parallel. A household using both, on both Trackers, sees a double-rise rather than the partial offset a fixed-price household would feel.
Eligibility, exit, and the small print
To sign up, a customer needs to already be on supply with Octopus, hold a working SMETS2 smart meter, and request the move via the Octopus dashboard or by emailing the team. There is no minimum-stay clause and no exit fee, which is unusual for a wholesale-linked product. The supplier reserves the right to move customers to the standard tariff if a meter falls out of half-hourly settlement.
The product also caps a daily kWh allowance. Above the daily cap (set above a typical household's burn), additional consumption defaults to a higher rate. The intent is to discourage the small but real cohort of customers who tried to run commercial-scale loads on a domestic Tracker contract in 2022-23.
The other small-print item is the price-publication route. Octopus publishes Tracker rates on the customer portal and via an API. A handful of community-built dashboards rebroadcast the data; one of the most-used is the Octopus Compare app maintained by independent developers. Octopus does not officially endorse third-party apps but tolerates them.
When Tracker is the wrong tariff
Tracker is wrong for a customer who cannot tolerate variability. Even a price floor of 18p and ceiling of 39p, in the example range from 2025, is a wider spread than fixed tariffs deliver. Households on a tight budget, particularly those receiving the Warm Home Discount of £150 announced in the DESNZ Warm Home Discount expansion document of 23 August 2025, are usually better served by a predictable fixed product or the standard variable.
It is also wrong for landlords running short tenancies. Tracker monthly billing variability complicates resident-billing arrangements; a fixed tariff makes those calculations cleaner.
For the median Octopus customer with steady consumption and an interest in catching a structural discount, Tracker is the lowest-friction smart tariff on offer. Just expect the occasional uncomfortable winter day.
What 2024 and 2025 actually looked like in numbers
Tracker's history is its main selling point. Over the past two calendar years the daily electricity unit rate has spent significantly more time below the Ofgem cap than above it, with the structural saving averaging around 9-11% on annualised consumption. The deepest single-month discount appeared in May 2024, when sustained low wholesale prices held the daily rate around 18-19p per kWh against a cap unit rate above 27p.
The most punishing month was February 2025, when a cold snap with low wind pushed the daily rate to 39p per kWh on several consecutive days. A Tracker customer using 30 kWh a day during that period paid roughly £5 more per day than a cap customer for that fortnight. Those weeks recur most years in some form; Tracker customers should budget for them rather than treat them as anomalies.
The 2025 annual reconciliation, published on the Octopus customer portal in January 2026, showed an average Tracker customer paying around £150 less than the equivalent cap-locked customer over the year, on typical 2,700 kWh electricity and 11,500 kWh gas. That is the structural saving net of the spike days.
For 2026 the forward picture is similar. Wholesale futures published by the N2EX exchange in April 2026 imply a calm summer and an autumn with moderate volatility. Tracker is likely to deliver a 7-10% saving against the cap unless a major supply disruption hits European gas markets.
Editorial disclaimer. Kaeltripton is an independent UK finance publisher. This article is general information for UK adults making their own decisions, not regulated financial advice. Tracker rates change daily and the figures quoted reflect Octopus and Ofgem publications dated before the last-reviewed date at the top of this page. Always confirm current rates with the supplier before switching. For complaints, refunds, or vulnerable-customer protection the formal route runs through the supplier first and then the Energy Ombudsman.
FAQ
Can the Tracker daily rate ever exceed the Ofgem cap?
Yes. The Tracker rate is set independently of the cap and can sit above it on spike days. The contractual daily ceiling, around 100p per kWh for electricity in 2025-26, is the only hard limit.
Where is tomorrow's Tracker rate published?
Tomorrow's rate is published on the Octopus customer portal each evening around 10pm. Several community apps such as Octopus Compare mirror the data via the public API.
Does a heat pump household save more on Tracker or Cosy?
Cosy usually wins for heat-pump-heavy consumption because the cheap windows are deeper than Tracker's daily price. Tracker can win for a heat pump household that cannot move load to specific hours and prefers a single daily price.
Is there an exit fee on this tariff?
No. Tracker has no minimum term and no exit fee. Customers can leave at any time and revert to a fixed or standard tariff.
What happens to consumption above the daily kWh cap?
Consumption above the daily cap is billed at a higher rate set out in the Tracker terms. The cap is well above a typical household's daily use, so most customers never trigger it.
Is a domestic Tracker contract suitable for small business use?
No. The daily kWh cap on Tracker is set above typical domestic use but below most small business consumption. Higher consumption defaults to a punitive surcharge rate.