Why Octopus Go or Intelligent Go can rise even when the price cap falls

This caught a lot of people out in April. Ofgem announced that the standard energy price cap for a typical dual-fuel home would fall to £1,641 from 1 April to 30 June 2026. A few weeks later, some Octopus Go and Intelligent Octopus Go customers were told their rates would rise again from 1 May.

At first glance that can look contradictory. In practice, it is two pricing systems running side by side. One covers standard default tariffs. The other covers optional EV tariffs with their own structure, risks and pricing choices.

1. What the price cap actually covers

Ofgem's cap is not a promise that every energy tariff in Britain must move down together. It is a limit on what suppliers can charge customers on a standard variable tariff, which is basically the default tariff many households end up on if they do not choose something more specific.

For 1 April to 30 June 2026, Ofgem says the typical annual cost falls by £117 to £1,641 for a dual-fuel household paying by Direct Debit. That is useful context, but it is not the same as a rule saying every fixed tariff, tracker, smart tariff or EV tariff must copy the same move.

2. Why Go and Intelligent Go sit outside that rule

Octopus Go and Intelligent Octopus Go are specialist EV tariffs. They are designed around cheap off-peak charging windows and, in Intelligent Go's case, smart scheduling that can place extra cheap slots outside the normal overnight window.

That means Octopus is not simply reselling a standard all-day tariff with a cap stuck on top. It is pricing a product with a high daytime rate, a very low off-peak rate and a model that depends on when people charge and how much flexibility the supplier can use.

Octopus's own Intelligent Go update already makes this clear in a different way. The company says variable Intelligent Go prices can change in future, even while the tariff keeps its guaranteed 23:30 to 05:30 whole-home off-peak window and up to six hours of discounted smart charging each day.

3. So why did prices fall on 1 April, then rise for 1 May?

Because the April cut and the May increase came from different pressures. Ofgem's April cap drop was driven largely by lower policy costs, with some wholesale relief mixed in. Octopus then passed through lower pricing on some EV tariffs from 1 April.

Later in April, MoneySavingExpert reported that some Go and Intelligent Go customers were told the off-peak rate would rise again from 1 May, with Octopus pointing to ongoing global volatility and Middle East conflict. The earlier April drop was a pass-through of lower policy costs, not a protected three-month price promise for these EV tariffs.

That can still feel jarring, especially if you had just recalculated your savings. The cleaner way to read the sequence is this: April was not proof that the tariffs had become price-cap products. It was one adjustment, followed by a separate repricing.

4. Why the notice period became part of the argument

The other reason people were annoyed was timing. Customers were told on 20 April about changes taking effect on 1 May, so many felt they had little time to react. Greg Jackson said Ofgem had removed the old 30-day notice requirement and that Octopus aims for about two weeks' notice, although this round landed slightly short of that.

That explanation may answer the rules point, but it does not remove the trust point. If you pick an EV tariff partly for predictability, a quick reversal after the April cut can still be frustrating.

5. Does that mean the tariff is suddenly bad value?

Not necessarily. A tariff can be annoying and still be competitive. The question is whether your own usage pattern still suits it.

• Heavy overnight home charging: you may still come out well ahead, even after the rise.
• Low mileage or lots of public charging: the higher daytime rate matters more, so the maths gets tighter.
• Big whole-home off-peak usage: dishwashers, washing machines and hot-water loads can still make the cheap window valuable.
• Intelligent Go households: the whole-home discount during scheduled smart-charge slots still matters, especially if those slots land outside 23:30 to 05:30.

6. What to check before you switch away

1. Your actual new unit rates and standing charge in the Octopus email or app, because public examples are regional and can mislead.
2. How many kWh you really charge at home in a normal month, not in your best-case month.
3. Whether your home can move other electricity use into the cheap window.
4. Whether you are comparing against another EV tariff, a fixed tariff or a standard tariff, because those are different trade-offs.
5. Whether simplicity now matters more to you than chasing the cheapest possible overnight rate.

If you barely charge at home, a simpler tariff may now be easier to justify. If you charge a lot at home and can use the off-peak window properly, Go or Intelligent Go may still be the right answer. The point is not to leave in a hurry. It is to compare your own bill, charger pattern and daytime use against the new prices.

The practical takeaway

The confusing part is not that the price cap fell. The confusing part is assuming that an EV tariff must follow it in lockstep. Go and Intelligent Go are optional specialist tariffs, so they can move on a different timetable.

Treat the April cut as background context, not as a guarantee. Then rerun your own numbers with the latest tariff details and decide from there.