MoneySavingExpert (MSE) founder Martin Lewis has shared his thoughts on an forthcoming price rise affecting certain Octopus Energy customers. The energy provider has informed customers of a price increase for both the Octopus Go and Intelligent Octopus Go (IOG) variable tariffs, which will come into effect from 1 May, 2026.

The overnight rate for Intelligent Octopus Go is set to climb to 6.9p/kWh. The rise was announced on 20 April, giving customers approximately 10 days' notice. Nevertheless, even with the May 2026 adjustment to 6.9p/kWh, it remains considerably below the standard national average, reports the Mirror.

A customer contacted Martin Lewis on X regarding the 1 May rate increase. Using the handle @Ken_w_davies, they wrote: "@MartinSLewis Octopus putting up their Octopus Go rates from 1st May even though they brought them down just weeks ago for the drop in the price cap? Doesn't sound right."

Martin Lewis replied: "Doesn't sound great, but just to be technical. Octopus Go is not a price capped tariff so it didn't move due to drop in Price Cap. It dropped due to the removal of some govt policy costs from energy bills (which is the same reason the cap moved but still they're separate).

"As its not priced capped and it is a variable tariff it is allowed to move the price as long as adequate notice is given. I'm afraid the only option is to ditch and switch elsewhere. You're supposed to get thirty days notice of yen changes some of you saying you got less.. We're going to check it out."

Octopus Energy chief executive Greg Jackson insisted the company is not flouting any regulations and maintains the tariffs remain "very cheap". He said: "Whilst rises are painful and we work very hard to avoid them (you can look back and see very few over the years on these tariffs) – these tariffs are still very cheap – typical users on this tariff will have a blended rate of around 18.3p/kWh – around 20% below the Price Cap, and the more they charge their car the bigger the saving."

"You don't need to buy a charger from us. The points about timing are well taken. In terms of "reviewed every three months" – although the price was changed less than three months ago – that was simply passing through the Government cut, in full. We haven't changed the price ourselves for four months (Octopus Go) and longer (for Intelligent Octopus Go) – and in terms of notice period, Ofgem removed the 30 days (we assume because it sometimes caused people to leave good value tariffs).

"We aim for about two weeks – slightly less this time, as we didn't want to email over the weekend when there'd be less support available. And perspective is important – an EV on these tariffs is about five to eight times cheaper per mile than a petrol car, despite the fact the UK has such high electricity prices."

Martin Lewis issued a reply, which reads: "Thanks for the reply Greg. Interesting to read. I must admit I didnt know Ofgem had ditched the 30 day notice rule, I think that's a shame. Clearly there are still some unhappy customers though. We're going to cover this in MSE news and will include your response in full."

On X, Octopus Energy's official account responded to a customer who enquired about the price rise. It explained: "That 3.49p off-peak rate on Intelligent Octopus Go (IOG) happened because we took the government's recent levy cuts (about £130 off a typical bill) and baked them directly into those smart windows.

"For those on a variable tariff like Flexible Octopus, your price is protected by the Ofgem Price Cap, which is currently falling but at a different pace because it averages out wholesale costs over several months to avoid sudden spikes. Each tariff reflects a different way of buying energy, either locking it in early or following the market's "weighted average" under the cap." Octopus Energy has been approached for comment.

Octopus Go is an entirely renewable energy tariff offering five hours of inexpensive, fixed-rate electricity daily from 12.30am to 5.30am. It's tailored specifically for electric vehicle (EV) motorists, regardless of car model or charger type. With rates ranging from 6.99p to 8p per kWh, customers can achieve significant savings, reducing overnight charging expenses to roughly 3p per mile, ideal for home and vehicular charging.

Octopus Energy is one of the largest energy suppliers for homes in the UK, serving more than 7.3 million households and about 12.9 million meters as of early 2025. It has around 24% market share, surpassing British Gas, and is well-known for its excellent customer service, having won awards and maintaining a 4.8-star rating on Trustpilot.