Price cap update: what the July 2026 rise means for Octopus Energy customers
Ofgem confirmed on 27 May 2026 that the energy price cap rises 13% from 1 July 2026, taking a typical dual-fuel direct-debit bill to £1,663 per year (or £1,862 on a like-for-like basis against the current £1,641). Electricity unit rates rise to 26.11p per kWh and gas to 7.33p per kWh. Standing charges are 57.19p/day for electricity and 29.04p/day for gas.
Octopus Energy customers on a standard variable tariff will see the new rates from 1 July. Anyone on a fixed tariff that ends before then should compare the new cap against Octopus Energy's renewal fixed-rate offer before it lapses to default.
Source: Ofgem press release, 27 May 2026 and unit rates and standing charges.
Last reviewed: 27 May 2026
TL;DR
- Octopus Energy Group Limited's UK retail entity Octopus Energy Limited holds the Ofgem domestic electricity and gas supply licence and serves around 7.8 million UK customer accounts as of early 2026, making it the largest domestic energy supplier in Great Britain by customer numbers.
- The headline tariff family is Octopus 12-Month Fixed, Flexible Octopus (the variable rate that tracks the Ofgem default tariff cap), Agile Octopus (a half-hourly wholesale-tracking tariff), Octopus Go and Intelligent Octopus Go (off-peak EV charging tariffs) and Octopus Tracker (a daily wholesale-tracking tariff).
- Citizens Advice has rated Octopus Energy in the top band of the quarterly supplier comparison table for several consecutive quarters; the current published star rating should be checked on citizensadvice.org.uk before drawing conclusions.
- Ofgem complaints per 100,000 customers data for Octopus Energy has consistently sat at or near the lowest in the published quarterly bulletin among the larger suppliers; the most recent quarterly figure is published at ofgem.gov.uk.
- The parent group is Octopus Energy Group Limited, a private UK company headquartered in London. Octopus Energy completed the acquisition of Shell Energy Retail's UK domestic supply book in December 2023, and absorbed customers from Bulb Energy under the Ofgem Supplier of Last Resort process in 2022.
Octopus Energy is the UK retail brand of Octopus Energy Group Limited, a private UK energy company founded in 2015 and headquartered in London. By customer numbers it is the largest domestic gas and electricity supplier in Great Britain, serving around 7.8 million customer accounts as of early 2026 after a sequence of large acquisitions including the Shell Energy Retail UK supply book in December 2023 and the Supplier of Last Resort transfer of Bulb Energy customers in 2022. This review covers the tariff range visible to UK customers in 2026, the supplier's track record on Ofgem complaints data and the Citizens Advice quarterly star rating, the Agile and Tracker wholesale-tracking products, the Intelligent Octopus Go off-peak EV tariff, the Kraken technology platform, the renewable-electricity claim, and the regulatory and ownership structure. Where unit prices are referred to, they are described structurally rather than quoted: the default tariff cap is revised every three months by Ofgem and any specific pence-per-kWh number quoted here would be out of date within weeks.
Tariffs available on Octopus Energy in 2026
Octopus Energy operates one of the widest named tariff ranges among UK domestic suppliers. The current tariff families visible on the supplier's published tariff schedule in 2026 are:
Octopus 12-Month Fixed. A fixed-term product with unit rates and standing charges locked for 12 months. The fixed tariff is the most direct comparison point against the Ofgem default tariff cap, and Octopus has historically priced the fixed tariff at or below the cap during periods of falling wholesale prices. The exact pricing relative to the cap changes when the product is refreshed and the supplier's current published tariff schedule is the authoritative source.
Flexible Octopus. The variable-rate default tariff. Unit rates and standing charges on Flexible Octopus track the Ofgem default tariff cap, which is recalculated for each quarterly cap period. Customers who do nothing at the end of a fixed-term contract drop onto Flexible Octopus. The tariff is dual-fuel capable, available on both credit meters and smart prepayment meters, and unit rates differ by Ofgem regional distribution zone.
Agile Octopus. A half-hourly tariff that tracks the day-ahead wholesale electricity market plus a fixed margin and the regulated network and policy components. Unit rates are published the previous afternoon for the following 24-hour period and can range from negative pence per kWh during periods of high renewable generation to materially above the cap during peak demand windows. Eligibility requires a working smart meter capable of half-hourly settlement. Agile is structurally a tariff for households that can shift consumption, including EV owners, battery storage owners, and households with thermal storage or heat pumps.
Octopus Go and Intelligent Octopus Go. Off-peak tariffs designed for households with an electric vehicle. Octopus Go offers a defined overnight cheaper-rate window. Intelligent Octopus Go integrates with compatible chargers and EVs to schedule charging within Octopus's preferred grid windows, in return for a lower off-peak unit rate over a longer effective window. Eligibility requires a smart meter, a compatible EV and a compatible charge point, and the supplier publishes the current list of compatible hardware on its product page.
Octopus Tracker. A daily-tracking tariff where unit rates change once per day in line with wholesale gas and electricity prices. Tracker is suited to customers comfortable with day-to-day price variation. Eligibility and signup are managed through the supplier's app.
This review does not quote specific unit prices because Ofgem updates the default tariff cap every three months and the Agile, Tracker and fixed-tariff prices are refreshed independently. Customers comparing tariffs should rely on the unit rate and standing charge displayed on their quote summary at the point of switching, and check the customer-specific tariff information label Octopus Energy is required to provide under Ofgem's Retail Energy Code.
Customer service track record
Three independent datasets are useful for assessing a UK supplier's customer service performance, and all three publish on a quarterly cycle.
Ofgem complaints per 100,000 customers. Ofgem publishes a quarterly bulletin showing the number of complaints received by each licensed supplier, normalised per 100,000 customer accounts. Octopus Energy has historically sat at or near the lowest published figure among the larger suppliers. The supplier's complaint volume has periodically risen during phases of large customer migration, including the integration of the Shell Energy Retail UK book in 2024 and the earlier Bulb Energy migration in 2022 and 2023. The current quarterly figure for Octopus Energy should be checked directly in the most recent Ofgem complaints data publication at ofgem.gov.uk.
Citizens Advice quarterly star rating. Citizens Advice publishes a supplier comparison table each quarter, scoring suppliers across five weighted dimensions including complaints handling, ease of contact, accuracy of bills, customer guarantees and customer service ratings. Octopus Energy has sat in the top band of the table for several recent quarters; the current published score is at citizensadvice.org.uk.
Energy Ombudsman case volume. Where a complaint cannot be resolved by the supplier within eight weeks, or where the supplier issues a deadlock letter sooner, the case can escalate to the Energy Ombudsman, the redress scheme approved by Ofgem under section 47A of the Electricity Act 1989. The Ombudsman publishes aggregate annual statistics on case volume by supplier. Octopus Energy case volumes broadly track the supplier's customer base scale.
The pattern that recurs in published complaints data for Octopus Energy is that smart-meter installation timing and final-bill timing on supply takeover are the most common categories of complaint, followed by billing accuracy in periods immediately after a migration from an acquired supplier.
Agile Octopus: half-hourly wholesale tracking
Agile Octopus is the most distinctive product in the supplier's range and the one most often cited in coverage of innovative UK retail tariffs. The mechanism is direct: the unit rate for each half-hour settlement period is published the previous afternoon, derived from the day-ahead wholesale market clearing price plus the supplier's margin and the regulated pass-through components.
Two consequences follow from this pricing structure. First, the unit rate during weekday evening peak (typically 16:00 to 19:00) can rise materially above the Ofgem cap unit rate, because that is when wholesale prices are highest. Second, the unit rate during periods of high renewable generation, often overnight in windy weather or midday in sunny weather, can fall to very low or occasionally negative figures.
The structural test for whether Agile is a good fit is the proportion of consumption a household can move out of the evening peak window. Households with a smart EV charger scheduled overnight, a heat pump with thermal storage, a domestic battery, or a dishwasher and tumble dryer programmed to run after 23:00, can shift a material share of consumption to lower-priced periods. Households whose consumption pattern matches the typical evening peak (cooking, lighting, television, washing) will see their effective average rate sit above the cap rate.
The supplier publishes an Agile Predictor tool that uses a household's smart meter consumption history to estimate the effective average rate under Agile pricing. The tool requires a smart meter consenting to half-hourly data sharing, which is itself a regulatory requirement of the Agile tariff.
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See partnership tiers →Intelligent Octopus Go and the EV proposition
Intelligent Octopus Go is the off-peak EV charging tariff that integrates with compatible chargers and electric vehicles to schedule charging within the supplier's preferred grid windows. The off-peak unit rate is materially below the daytime cap rate. The published off-peak window is overnight, with the precise hours varying by tariff version.
The structural difference between Intelligent Octopus Go and the simpler Octopus Go is the integration layer. With Intelligent Octopus Go, the customer specifies the charge target and the departure time, and the supplier schedules the actual charging within the off-peak window, frequently outside the customer's explicit schedule. The customer receives the off-peak unit rate for those scheduled hours regardless of when the charge actually occurs within the off-peak window.
Eligibility requires a smart meter capable of half-hourly settlement, a compatible EV, and a compatible charge point. The supplier publishes the current compatible hardware list on its product page. For households where the EV, the charger and the smart meter combination is not eligible, Octopus Go offers a simpler product without the integration layer, with a slightly higher off-peak unit rate and no scheduling support.
The economic case for Intelligent Octopus Go scales with EV mileage and the proportion of charging that occurs at home rather than at public charge points. A household charging an EV overnight at the off-peak rate, instead of at a peak daytime public charger or at the standard cap rate, pays a fraction of the per-kWh cost. The calculation depends on the customer's annual mileage, the EV's efficiency in miles per kWh, and the relevant off-peak rate at the time of switching.
Kraken: the technology platform
Kraken is the customer management and billing platform built by Octopus Energy Group and now licensed to other energy suppliers globally. The platform handles customer accounts, billing, smart meter data ingestion, tariff calculation including the half-hourly logic underpinning Agile and Intelligent Octopus Go, and the field service workflow for meter installation and supply changes.
Kraken is licensed under the separate Kraken Technologies brand to other UK and international suppliers, including E.ON UK for its domestic operations, Origin Energy in Australia, and other suppliers in the United States, Japan, Germany and France. The licensing model is a per-customer-per-year subscription, generating a revenue stream for Octopus Energy Group that sits alongside the retail energy business.
For UK Octopus Energy customers, the practical effect of the Kraken platform is in the customer-facing app and online portal. The app surfaces real-time consumption from smart meters, historical billing data, tariff comparison views, and the controls for managing the Intelligent Octopus Go charging schedule. The platform's smart meter data ingestion is the foundation of the Agile Predictor tool and the consumption-based tariff recommendation logic.
Price cap protection and standing charge approach
The Ofgem default tariff cap, introduced under the Domestic Gas and Electricity (Tariff Cap) Act 2018, sets a maximum unit rate and standing charge that licensed suppliers may charge customers on a default or standard variable tariff. The cap is recalculated each quarter using a wholesale-cost methodology Ofgem publishes openly. Customers on a fixed-term tariff are not protected by the cap and pay the contracted unit rate and standing charge for the duration of the fixed term.
Flexible Octopus is priced at or close to the cap unit rates and standing charges for the relevant Ofgem regional distribution zone. Standing charges differ by region, reflecting the different network distribution costs Ofgem allows for each of the 14 distribution zones. The supplier's published tariff information label, which Ofgem requires to be issued to each customer, sets out the customer-specific unit rate and standing charge in pence per kWh and pence per day.
Standing charges in the Ofgem default tariff cap have risen materially since 2022, reflecting the cost of supplier-of-last-resort exercises and the recovery of network and policy costs. Octopus Energy, like all suppliers operating on the cap, applies the standing charge per day regardless of consumption. Customers with very low consumption who feel disadvantaged by the standing-charge structure can raise the issue with Ofgem, which has consulted publicly on alternative standing-charge structures including a zero-standing-charge tariff option.
Green credentials
Octopus Energy markets 100 percent renewable electricity to domestic customers across its tariff range. The mechanism behind that claim, as for most UK retail suppliers making the same claim, is the purchase of Renewable Energy Guarantees of Origin (REGO) certificates equivalent to the customer's consumption. REGOs are issued by Ofgem to renewable generators and traded separately from the underlying electricity.
Octopus Energy Group also operates a substantial renewable generation business through Octopus Energy Generation, which holds equity in onshore wind, solar and offshore wind projects across the UK and continental Europe. The retail supplier purchases a proportion of its electricity directly from generation assets within the Octopus Energy Generation portfolio under Power Purchase Agreements, supplementing the REGO-backed claim with physical sourcing in some periods.
The annual Fuel Mix Disclosure published under the Electricity (Fuel Mix Disclosure) Regulations 2005 sets out the precise percentage breakdown of supplier-procured generation by fuel source for the previous reporting year. Customers wanting a deeper-than-REGO renewable assurance should compare the Fuel Mix Disclosure of multiple suppliers and consult Ofgem's published guidance on what a "100 percent renewable" claim does and does not mean. Octopus Energy does not currently hold B Corp certification at the UK retail entity level.
Ownership, regulation and structure
The UK supply licence is held by Octopus Energy Limited, registered at Companies House. The licence sits within Ofgem's published register of licensed domestic gas and electricity suppliers, which can be searched at ofgem.gov.uk via the supplier licence lookup tool. The supplier operates under the standard Ofgem Domestic Gas and Electricity Supply Licence conditions, including the Standards of Conduct, the Retail Energy Code, the Smart Metering Installation Code of Practice, and the Priority Services Register requirements for vulnerable customers.
The ultimate parent is Octopus Energy Group Limited, a privately held UK company headquartered in London. Major external investors include Origin Energy of Australia, Tokyo Gas of Japan, the Canada Pension Plan Investment Board, and Generation Investment Management. The group's UK and international filings are publicly accessible at find-and-update.company-information.service.gov.uk under Octopus Energy Group Limited and Octopus Energy Limited.
The Shell Energy Retail UK supply book was acquired in December 2023, integrating around 1.4 million domestic customer accounts onto the Octopus Energy retail platform. The Bulb Energy customer book was transferred to Octopus Energy under the Ofgem Supplier of Last Resort process in late 2022, integrating around 1.5 million accounts. Both migrations contributed to the customer base scale that places Octopus Energy as the largest UK domestic supplier by accounts in 2026.
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How we verified this article
Tariff structure and customer numbers cross-checked against the supplier's published tariff schedule, the Ofgem licence register at ofgem.gov.uk, and the Companies House filings for Octopus Energy Limited and Octopus Energy Group Limited.
Customer service track record summarised from the quarterly Ofgem complaints data publication, the Citizens Advice supplier comparison table, and the Energy Ombudsman annual statistics. Specific quarterly figures change between publications and the most recent published figure is the authoritative source.
Acquisition history confirmed against the Ofgem Supplier of Last Resort designation for Bulb Energy in 2022 and the FTSE-listed disclosure for the Shell Energy Retail UK supply book transfer in 2023.
Renewable claim mechanism described against the Ofgem REGO scheme rules and the annual Fuel Mix Disclosure published under the Electricity (Fuel Mix Disclosure) Regulations 2005.
| Editorial note: Kaeltripton.com is an independent editorial publisher and is not authorised by the Financial Conduct Authority, Ofgem, MCS, TrustMark or Gas Safe. This article is for informational purposes only and does not constitute regulated advice. UK energy regulations, prices, tariff caps and grant schemes change without notice. Always verify current requirements directly on GOV.UK, ofgem.gov.uk, mcscertified.com, gassaferegister.co.uk or trustmark.org.uk, and obtain a fixed written quote from a registered tradesperson before committing to work. |
Frequently asked questions
Is Octopus Energy the largest UK domestic energy supplier in 2026?
Yes. By customer account numbers, Octopus Energy is the largest domestic gas and electricity supplier in Great Britain as of early 2026, with around 7.8 million customer accounts. The current published figure is at ofgem.gov.uk in the quarterly retail market segment data.
How does Agile Octopus pricing actually work?
Agile Octopus is a half-hourly tariff. The unit rate for each 30-minute settlement period is published the previous afternoon and is derived from the day-ahead wholesale electricity market price plus a fixed supplier margin and the regulated network and policy components. The rate can fall to negative figures during periods of high renewable generation and rise above the Ofgem cap unit rate during weekday evening peak. A working smart meter capable of half-hourly settlement is required.
Does Octopus Energy supply 100 percent renewable electricity?
Octopus Energy markets 100 percent renewable electricity through the purchase of Renewable Energy Guarantees of Origin (REGO) certificates equivalent to customer consumption, supplemented by direct generation from the Octopus Energy Generation portfolio under Power Purchase Agreements. The precise percentage breakdown by fuel source is published annually in the Fuel Mix Disclosure required under the Electricity (Fuel Mix Disclosure) Regulations 2005.
What is the Ofgem complaints record for Octopus Energy?
Ofgem publishes a quarterly bulletin of complaints per 100,000 customers for each licensed supplier. Octopus Energy has historically sat at or near the lowest figure among the larger suppliers. The most recent quarterly figure is published at ofgem.gov.uk and should be checked there for the current period.
How does Intelligent Octopus Go compare to Octopus Go?
Both are off-peak EV charging tariffs with a lower overnight unit rate. The difference is the integration layer. Intelligent Octopus Go connects to compatible chargers and EVs to schedule charging within Octopus's grid windows. The customer specifies the charge target and the departure time, and the off-peak unit rate applies for the scheduled hours regardless of when the charge actually completes. Octopus Go is a simpler product without scheduling integration and has a slightly higher off-peak unit rate.
Was Bulb Energy absorbed by Octopus Energy?
Yes. Bulb Energy customers were transferred to Octopus Energy in late 2022 under the Ofgem Supplier of Last Resort process. The Shell Energy Retail UK supply book was separately acquired in December 2023, integrating around 1.4 million additional customer accounts. Both events contributed to the customer base that places Octopus Energy as the largest UK domestic supplier by accounts in 2026.
Sources
- Ofgem default tariff cap
- Ofgem complaints data per 100,000 customers
- Citizens Advice supplier comparison table
- Energy Ombudsman case volume statistics
- Companies House: Octopus Energy Limited filings
- Electricity (Fuel Mix Disclosure) Regulations 2005
Related guides
- Best Energy Suppliers UK 2026
- UK Energy Price Cap 2026
- E.ON Next Review UK
- Scottish Power Review UK
- Good Energy Review UK
Last reviewed: 17 May 2026 | Chandraketu Tripathi, finance editor
