Why Octopus Go and Intelligent Go can rise as the 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.

The confirmed October cap proves the same point from the other direction. Ofgem says the cap for default tariffs will rise from 1 October to 31 December 2026, but that still does not make Go or Intelligent Go ordinary price-cap tariffs. Octopus is currently offering both EV tariffs as fixed rates, so the quote and tariff term on your account matter more than the direction of the next cap.

At first glance the April sequence looked contradictory. In practice, it was 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 said the typical annual cost fell by £117 to £1,641 for a dual-fuel household paying by Direct Debit. The cap rose again for July to September and Ofgem has confirmed another increase for October to December. Those figures are useful context, but they are not 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.

Intelligent Go keeps a 23:30 to 05:30 whole-home off-peak window and up to six hours of managed EV charging each day. For smart-charging slots outside that fixed window, confirm with Octopus which household rate applies to your tariff before shifting appliances or home-battery charging. Keep your tariff version and start date, check the current Octopus smart-tariff terms and compare the corresponding billed half-hours.

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 gets the night rate from 23:30 to 05:30. Outside that fixed window, do not assume an EV smart-charging slot discounts other household use: confirm your applicable tariff with Octopus before moving household loads.

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, then check the live Octopus Go or Intelligent Octopus Go page before making a switch decision.

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 and later cap rises as background context, not as automatic instructions. Then rerun your own numbers with the latest tariff details and decide from there.