Where this guide disagrees with Which? on Octopus Energy

Affiliate disclosure: this post contains an Octopus Energy referral link. If you use it, both of us get £50 bill credit: the same £50 any Octopus referral earns, just attributed to me. It doesn't change the price you pay or the tariff you can pick.

Which? (opens in new tab) is the UK's most rigorous independent energy reviewer. Their annual customer-satisfaction survey is the gold-standard signal for the UK supplier market, and Octopus Energy has been a Which? Recommended Provider for nine consecutive years (opens in new tab). My own Octopus Energy review, now six and a half years in, mostly lines up with their conclusion: Octopus is one of the strongest UK domestic suppliers on the criteria that matter most to most households.

But not all of my position lines up with theirs. Three places, specifically. The point of this post is to lay them out, because telling readers where you disagree with the gold-standard reviewer is exactly the kind of editorial honesty that should be visible on a referral site.

Where Which? and I agree

The agreements are bigger than the disagreements, so it's worth getting them on the table first.

Customer service. Which?'s satisfaction surveys consistently place Octopus at or near the top of UK domestic suppliers on the dimensions they measure: billing accuracy, complaint handling, ease of contact, switching experience. That matches my six and a half years as a customer: two house moves with zero friction, same-day email replies, in-app chat that resolves most things in minutes, and one 25-minute phone wait across nearly seven years (more on that in the main review).

Independence and scale. Which? notes that Octopus passed the 2021–22 supplier-failure cull cleanly when dozens of smaller suppliers went under, and has since become the largest UK electricity supplier (opens in new tab) serving 7.7 million UK households (Octopus figures, December 2025). I agree that scale matters here. A supplier you depend on for an essential utility needs the balance sheet to survive wholesale shocks.

Trustpilot. Octopus sits at 4.8/5 from over 700,000 reviews (opens in new tab) (April 2026), which is genuinely high for a regulated utility. Which?'s survey-based satisfaction scores and Trustpilot's volunteered ratings agree, which is the signal you actually want.

The Recommended Provider streak is meaningful. Nine consecutive years through a wholesale-price crisis, an industry shake-out, and an Ofgem standing-charge reset is a real signal of stability, not a coincidence of survey wording.

Disagreement 1: the 2026 survey put E.ON Next slightly ahead, and I still pick Octopus

Which?'s 2026 energy customer satisfaction survey (opens in new tab) rated E.ON Next as the highest-scoring large UK energy supplier with a 66% customer score. Octopus retained its Recommended Provider status but didn't come out top on the headline number this time. By the strict Which? methodology, E.ON Next is now the most customer-satisfied large supplier.

I had Octopus electricity and E.ON Next gas running side by side for nearly four years (my Bulb gas account was moved to E.ON Next when Bulb went into special administration in 2021, and I kept the split until my second house move in 2025). Both are credible. E.ON Next is responsive and competitive on dual-fuel Fixed pricing. The Which? survey result is fair.

Where I'd nudge readers away from following the headline score is on what Which?'s methodology doesn't capture:

• Tariff range. Octopus runs Flexible, Fixed, Tracker, Agile, Go, Intelligent Octopus Go, Cosy and Flux. E.ON Next runs a shorter range built around Fixed and Flexible variants. For a household with no EV, no solar and no heat pump, that doesn't matter. For households who have any of those, the right Octopus tariff (Cosy for heat pumps, Flux for solar + battery, Intelligent Octopus Go for EVs) can be the supplier-choice that saves real money, not the headline service score. See the Octopus tariff guide for the full lineup.
• The Kraken platform. Octopus runs its UK operations on its own in-house technology platform (Kraken) and licenses it to other suppliers. That's why the app works the way it does, why bills are accurate without manual intervention, and why edge cases like a wrong meter reading get fixed in minutes rather than weeks. Which?'s survey scores reflect the output of that platform indirectly (via billing-accuracy scores), but it doesn't credit the tech directly.
• In-house EV and heat-pump products. Octopus has been one of the most aggressive UK suppliers in shipping integrated EV and heat-pump products (Intelligent Octopus Go, Octopus Energy Services). Households actively transitioning kit benefit from one supplier handling tariff, charging and installation rather than coordinating three separate providers.

So my read of the 2026 survey: E.ON Next genuinely won the customer-service race that year, and that's fair. But Octopus still wins the overall supplier choice for any household that benefits from the tariff range or smart-home integration.

Disagreement 2: Which?'s methodology under-credits smart tariffs

Which?'s energy satisfaction survey is built around the universal experience all UK domestic customers share: billing, complaint handling, switching, ease of contact, and price perception. Those are the dimensions that apply to every household, so they're the dimensions Which? scores.

What that methodology doesn't fully capture is the financial upside of being on the right smart tariff. The customers benefiting most from Octopus's tariff range (EV owners on Intelligent Octopus Go saving £400 to £800 a year on overnight charging, solar + battery households on Flux running near-break-even on bills, heat-pump households on Cosy) are a minority of the customer base. The Which? scoring spreads their satisfaction across the broader sample, so the tariff-range upside shows up as a modest contributor to the overall score rather than as the differentiating factor it actually is.

That's a defensible methodology choice for a publisher serving a general audience. But it means if you're in one of those minority groups, the Which? score genuinely under-credits the case for Octopus over a supplier with a simpler tariff range. A 66% customer score at E.ON Next on a simple Fixed tariff is good for someone whose usage is flat. It's irrelevant to a household where the right tariff choice is worth several hundred pounds a year on top of any service-quality difference.

The honest framing: Which?'s score is the right starting point for households with flat usage and no smart-home kit. For households with EVs, solar, batteries, or heat pumps, the score is too coarse to drive the decision.

Disagreement 3: Octoplus, Saving Sessions and free-electricity events don't show up in Which?'s scoring

Octopus operates a rewards engine that returns real money to engaged customers:

• Octoplus is the loyalty programme: monthly spin-the-wheel rewards, partner offers, and bonus credits for completing energy-related tasks (signing up to a smart tariff, joining Saving Sessions, completing meter reads on time).
• Saving Sessions pays Octopus customers for shifting their usage during high-demand windows announced a day in advance. Typical earn rate is £1 to £3 per session for a household making a modest shift. Across a winter season, engaged participants earn £30 to £100+ in bill credit.
• Free-electricity events are periodic windows (usually on weekend afternoons of high renewable generation) where Octopus customers pay nothing for the electricity they use during the window. Genuinely free, not a discount.

None of those translate cleanly into the Which? satisfaction survey, because none of them are universal customer experiences. Engaged customers benefit; passive customers don't. The Which? score averages across both.

If you're the kind of customer who'll engage (open the app once a week, opt into Saving Sessions, run the dishwasher during a free-electricity event), Octopus returns more money to you than any other major UK supplier. That's a real differentiator. It just doesn't show up in Which?'s headline number.

Which? isn't wrong to leave it out. Their methodology is built for a representative customer, not for the engaged power-user. But if you're reading this site, you're probably more engaged than average, and the rewards engine is worth weighting in your decision more heavily than Which?'s methodology can.

Where Which? is firmly right and I'd repeat their position word-for-word

I want to be clear that the disagreements above are at the margins. The places I'd echo Which? exactly:

• No supplier should be assumed bulletproof indefinitely. The 2021–22 supplier failures killed Bulb, Avro, Green, Utility Point and dozens more. Octopus passing scale and balance-sheet thresholds is a positive signal, but customers should still factor in counterparty risk.
• Customer service quality is the most-weighted single criterion for most households, and Octopus's score on Which?'s methodology is genuinely strong.
• Price cap regulation means there's no single "cheapest" supplier in the post-2022 UK market. Standard variable tariffs are all bound by the same Ofgem cap. What varies is Fixed-deal pricing, smart-tariff structure, and rewards. Which?'s framing on this is exactly right.

So who's right?

We both are, on the criteria each of us prioritises.

Which? is right on customer-service-driven supplier choice. Their methodology is rigorous, independent, replicable across years, and applied uniformly to every supplier they cover. If you want one signal to drive a switching decision and you have flat household usage, the Which? Recommended Provider list is the right shortlist.

My position is more opinionated. For households likely to benefit from tariff innovation or rewards engagement, I weight those things heavily enough that the Which? score under-credits Octopus's case. For households who won't engage with either, I'd nudge toward Which?'s framing more cleanly.

The practical answer: read the Which? coverage as the baseline, read my Octopus review for the engaged-customer view, and decide which of those describes your household better.

If you're going to switch to Octopus anyway, using a referral link adds £50 bill credit at zero cost to you, payable after your first direct debit clears.

Where this guide disagrees with Which? FAQs

Did Which? rate E.ON Next ahead of Octopus in 2026?

Yes. In the Which? 2026 energy customer satisfaction survey (opens in new tab), E.ON Next scored 66% as the highest-rated large UK energy supplier. Octopus retained its Recommended Provider status but didn't take the top headline number that year. On the strict customer-service criteria Which? measures, E.ON Next won the 2026 round.

Why do you still recommend Octopus over E.ON Next?

For households with no EV, no solar, no battery and no heat pump on a flat usage curve, I'd be comfortable with either supplier and the Which? score is a reasonable tiebreaker. For households who'd benefit from a smart tariff (Tracker, Agile, Intelligent Octopus Go, Cosy, Flux), Octopus has the tariff range that E.ON Next doesn't, and the Kraken platform that makes the smart-tariff economics actually work in practice. The decision should hinge on which household profile you have.

Is Which? wrong about Octopus?

No. Which?'s methodology is rigorous and applied uniformly. My disagreements are at the margins of what their methodology is designed to measure. Which? scores customer-service quality and billing accuracy well. It under-credits tariff innovation and rewards engines because those don't apply uniformly across the customer base. Both observations can be true at the same time.

Does Which? credit Octoplus and Saving Sessions in its scoring?

Not directly. Which?'s satisfaction survey measures dimensions every customer experiences (billing, complaints, switching, ease of contact). Engagement-based features like Octoplus rewards, Saving Sessions earnings and free-electricity events benefit only the customers who actively use them, so they average out in a population-level score. That's a methodology choice, not a flaw. But it means engaged customers will under-estimate Octopus's value if they read Which?'s score as a complete answer.

How does the Which? Recommended Provider status work?

Which? awards Recommended Provider status based on annual customer-satisfaction survey results combined with passing minimum threshold scores on key service dimensions. Octopus has held the status for nine consecutive years, which is a strong stability signal across a period that saw dozens of UK suppliers fail. The streak survived the 2021–22 wholesale crisis, the Ofgem standing-charge reset, and Octopus growing from a challenger to the largest UK electricity supplier.

Should I switch to whichever supplier Which? rates highest?

Read the Which? score as the baseline customer-service signal, then layer in: tariff fit (do you need a smart tariff for an EV, heat pump or solar?), price-cap quarter (are there Fixed deals below the next forecast cap?), and engagement (will you use rewards programmes?). The Which? rating is the most rigorous single source on customer service. It's not the same thing as the right supplier for your specific household.

You might also like

• Octopus Energy review: 6 years as a customer
• Octopus Energy vs E.ON Next referral: which gives you more?
• What does Martin Lewis say about Octopus Energy?
• Which Octopus Energy tariff is right for you?

Sources

• Which? 2026 energy survey: https://www.which.co.uk/reviews/energy-companies/article/energy-companies/which-energy-survey-results-ajqM43e6ycY8 (opens in new tab)
• Octopus Energy customer numbers (December 2025): https://octopus.energy/press/largest-electricity-supplier-market-share/ (opens in new tab)
• Octopus Energy Trustpilot: https://uk.trustpilot.com/review/octopus.energy (opens in new tab)
• Ofgem energy price cap (1 April – 30 June 2026): https://www.ofgem.gov.uk/information-consumers/energy-advice-households/energy-price-cap-explained (opens in new tab)