Octopus Energy Sainsbury’s Energy (September 2026)
Overview
Octopus Energy leads on variable pricing and customer reviews, though Sainsbury's Energy matches it closely on fixed prices.
Based on the available evidence, Octopus Energy may suit households prioritising cheaper standard variable prices and higher customer review scores. Sainsbury's Energy matches Octopus on fixed tariff pricing, though it lacks app and Citizens Advice data in this comparison.
About Octopus Energy and Sainsbury's Energy
Who are Octopus Energy?
Started in 2015, Octopus Energy is the UK's largest domestic energy supplier. It has grown through its own growth and by buying other suppliers such as Bulb and Shell Energy Retail. Backed by the Octopus Group and global investors, it runs its billing and customer service on its own technology platform. A key difference is that its Flexible tariff has no exit fees, while some fixed tariffs may charge a fee for leaving early.
Products & services
Awards & recognition
Who are Sainsbury's Energy?
Sainsbury's Energy is a partnership between one of the UK's most recognised supermarket brands and E.ON Next. It is not a licensed supplier itself; E.ON Next holds the licence and supplies the energy. This means customers get their power from one of the UK's largest suppliers while dealing with the Sainsbury's Energy brand. The main feature that sets it apart is its link to the Nectar loyalty programme, allowing customers to earn bonus points on their shopping.
Products & services
Awards & recognition
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Tariffs and pricing
The cheapest tariff in this comparison is Flexible Octopus, a variable deal costing £1,598 a year. By comparison, Sainsbury's Standard Variable costs £1,611 a year. This makes Octopus Energy £13 cheaper annually—roughly £1 a month. Neither variable tariff carries an exit fee.
For households looking to lock in rates, the cheapest fixed tariff from Octopus Energy is £1,642 a year on a 12-month contract, which includes a £100 exit fee. Sainsbury's Energy offers a similarly priced fixed deal at £1,640 a year, but this requires a 24-month contract and carries a £200 exit fee. While the annual costs are effectively identical, Sainsbury's Energy requires a longer commitment and higher early exit penalties.
Octopus Energy and Sainsbury’s Energy: tariff options
Octopus Energy
These are the household tariffs currently available in our comparison data. Prices and availability can vary by region, meter type and payment method.
Sainsbury’s Energy
These are the household tariffs currently available in our comparison data. Prices and availability can vary by region, meter type and payment method.
Customer reviews
On Trustpilot, Octopus Energy scores 4.8 out of 5 across 857,633 reviews, with 90% of users awarding five stars. Sainsbury's Energy holds a score of 4.3 out of 5 from 3,139 reviews, comprising 80% five-star and 10% one-star ratings.
Reviewers frequently note that Octopus Energy staff are polite and efficient with account queries, though some report communication delays, including unanswered emails and waits to resolve technical issues. Similarly, Sainsbury's Energy customers highlight helpful staff and rapid responses to online messages. Conversely, some users mention unexpected billing errors and delayed follow-ups from the support team.
The latest Which? annual survey awards Octopus Energy an overall score of 74, compared to 71 for Sainsbury's Energy. Both suppliers receive 4 out of 5 for overall customer service. However, Sainsbury's Energy achieves a higher smart meters sub-score, earning 8 out of 10 against Octopus Energy's 5 out of 10.
App quality and features
Octopus Energy provides account management apps on both major platforms. The iOS app scores 4.8 out of 5 from 254,000 ratings, while the Android version scores 4.4 out of 5 from 47,238 ratings on the Google Play Store. The Android app also records over a million installs.
A recent sample of iOS reviews for Octopus Energy indicates mixed feedback regarding technical issues and post-switch problems, though users note that bugs are typically resolved. The app receives frequent updates, suggesting active maintenance.
There is currently no app data or rating information available for Sainsbury's Energy in this comparison.
Customer service and support
Average wait: 1.3 min
Hours: Mon–Thu 9am–5pm, Fri 9am–4pm, closed Saturday, closed Sunday
Replies: 86% within 2 days
Hours: 24/7
According to Citizens Advice, Octopus Energy scores 3.67 out of 5, ranking 4th overall. The supplier records an average call centre wait time of 1 minute 17 seconds and responds to 86.1% of customer emails within two days. It also maintains formal vulnerability commitments registered with Citizens Advice.
At a brand level, Octopus Energy accepts Direct Debit, Cash/Cheque, and Prepayment. Phone lines operate Monday to Thursday from 9am to 5pm, and Friday from 9am to 4pm, remaining closed on weekends.
Citizens Advice data for Sainsbury's Energy is absent from this comparison, so direct comparisons of call wait times or email response speeds are not possible.
Complaints and performance
Complaint figures are shown with each supplier’s reporting period. No winner is declared when periods differ or one figure is missing.
Green energy comparison
Octopus Energy
Octopus Energy offers 100% zero-carbon electricity. According to Citizens Advice data from January to March 2026, its electricity fuel mix is a mostly renewable mix, with some nuclear. The company operates a £7 billion renewables portfolio and invests directly in solar power and heat pumps. It also runs the Octopus Fan Club, which gives cheaper electricity to customers living near certain wind turbines when the wind blows.
Sainsbury's Energy
Sainsbury's Energy offers 100% zero-carbon electricity on its Fix and Reward tariffs, which is matched using Renewable Energy Guarantee of Origin (REGO) certificates. It also helps customers lower their carbon footprint by offering discounts on solar panel installations, heat pumps, and electric vehicle chargers, as well as sharing energy-saving tips.
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | Octopus Energy |
| Overall customer service | Octopus Energy |
Octopus Energy leads on variable pricing and customer reviews, though Sainsbury's Energy matches it closely on fixed prices.
Based on the metrics reviewed, Octopus Energy leads on standard variable pricing, Trustpilot ratings, and app availability. Sainsbury's Energy offers comparable fixed tariff pricing and achieves a higher smart meters score with Which?, but lacks app and Citizens Advice data in this comparison.
Octopus Energy may suit households seeking the cheapest variable rate and app-based account management. For those preferring a fixed deal, both suppliers offer similar annual costs, though Sainsbury's Energy requires a 24-month contract and carries a higher exit fee compared to Octopus Energy's 12-month term.
- Cheaper standard variable tariff
- 4.8 out of 5 Trustpilot rating from over 850,000 reviews
- Available apps on both iOS and Android
- £100 exit fee on its cheapest fixed deal
- Scores lower than Sainsbury's Energy for smart meters with Which?
- Fixed tariff is effectively identical in price to Octopus Energy
- Scores 8 out of 10 for smart meters in the latest Which? survey
- £200 exit fee on its cheapest fixed deal
- Missing app and Citizens Advice data in this comparison
- 10% of Trustpilot reviews are one-star
Frequently asked questions
Which supplier is better overall?
Based on the available evidence, Octopus Energy is the better choice. It offers a cheaper standard variable tariff, higher Trustpilot and Which? scores, and highly rated apps. Sainsbury's Energy matches Octopus on fixed tariff prices but lacks app and Citizens Advice data in this comparison.
Which supplier offers the cheaper tariff?
Octopus Energy offers the cheaper overall deal. Its Flexible Octopus variable tariff costs £1,598 a year, which is £13 cheaper than Sainsbury's Energy's standard variable option. However, their cheapest fixed deals are effectively identical in price.
Do customers prefer Octopus Energy or Sainsbury's Energy?
Octopus Energy ranks higher on the data we compared. It scores 4.8 out of 5 on Trustpilot from over 850,000 reviews, while Sainsbury's Energy scores 4.3 from just over 3,000 reviews. Octopus Energy also scores slightly higher overall in the latest Which? survey.
Does Sainsbury's Energy have an app?
There is no app data available for Sainsbury's Energy in this comparison. Octopus Energy, on the other hand, has highly rated apps on both iOS and Android.
How long does it take Octopus Energy to answer the phone?
According to Citizens Advice, the average call centre wait time for Octopus Energy is 1 minute 17 seconds. Call wait time data is not currently available for Sainsbury's Energy.
Should I choose Octopus Energy or Sainsbury's Energy?
If you want a cheaper variable tariff and highly rated customer service, Octopus Energy is the stronger option. If you are looking for a fixed deal, both suppliers cost about the same, though Sainsbury's Energy ties you in for 24 months compared to Octopus Energy's 12-month term.
Are there exit fees with these suppliers?
Neither supplier charges an exit fee on their standard variable tariffs. However, their cheapest fixed deals do have penalties for leaving early: Octopus Energy charges a £100 exit fee, while Sainsbury's Energy charges £200.
How do these suppliers perform in Which? surveys?
Octopus Energy scores 74 overall with Which?, while Sainsbury's Energy scores 71. Both suppliers score 4 out of 5 for overall customer service, but Sainsbury's Energy performs better on the smart meters sub-score, earning 8 out of 10 compared to 5 for Octopus Energy.
What changed this month
This month, Sainsbury’s Energy's shortest fixed term rose from 12 months to 24 months, Octopus Energy's iOS app days since last update fell from 6 to 1, and Octopus Energy's play store days since last update fell from 2 to 1. There were 16 other data changes this month — see the full changelog below for details.
Data changes this month (22)
Octopus Energy
- Trustpilot reviews837,814 → 857,633
- iOS app ratings count249,000 → 254,000
- iOS app days since last update6 → 1
- iOS sampled reviews avg stars2 → 1.67
- Play Store rating4.3956046 → 4.3669577
- Play Store ratings count47,091 → 47,238
- Play Store days since last update2 → 1
- Play Store positive ratings %85.5 → 84.5
- Play Store negative ratings %11 → 11.7
- Play Store neutral ratings %3.5 → 3.7
- Play Store net-positive %74.5 → 72.8
- Cheapest variable tariff£1,792.32 → £1,598.38
- Cheapest fixed tariff£1,841.19 → £1,641.76
- Cheapest tariff£1,792.32 → £1,598.38
- Tariff count3 → 2
- Fixed tariffs available2 → 1
Sainsbury’s Energy
- Trustpilot reviews3,127 → 3,139
- Trustpilot negative reviews replied %35 → 31
- Cheapest variable tariff£1,804.81 → £1,610.88
- Cheapest fixed tariff£1,840.79 → £1,639.64
- Cheapest tariff£1,804.81 → £1,610.88
- Shortest fixed term12 months → 24 months
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Written by
Rob Gibbs
Hi, I'm Rob, and I run Energy-Review.co.uk. I initially started this project in 2018 when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data-backed reviews on all the suppliers available. Since then, I have spent a lot of time (too much, some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible, and any data is backed up by a source where necessary. I have also started writing guides on various energy-related topics, which hopefully you will find useful. If you find any issues, please use our contact form to let us know.