A plain-English look at Octopus Intelligent Go for UK EV drivers — overnight charging from 7p/kWh, how the smart charging window works, and the £50 switch credit.
Why the tariff matters more than the car
The single biggest factor in what an electric car costs to run is the rate you pay overnight. A dedicated EV tariff with a cheap off-peak window turns home charging into the cheapest motoring most people will ever do; charging on a standard flat rate throws most of that advantage away.
The saving comes from shifting load, not from using less. Set the car or the wallbox to charge inside the cheap window and the rest looks after itself.
What to check before switching
The off-peak rate and the exact hours, the day rate outside them, any standing charge difference, and whether the tariff requires a smart meter or a specific charger. Compare the whole bill, not just the headline overnight figure — a very low night rate with a high day rate can cost more overall for a household at home all day.
If you have solar, check the export rate too. Import and export together decide whether adding a battery is worth it.
Getting the most from it
Schedule everything you can into the cheap window: the car, the dishwasher, the washing machine, a hot water immersion if you have one. A house that shifts most of its load overnight sees the saving on everything, not only the car.
Check the schedule actually ran. Charging that silently failed because the car was locked out of the app or the wallbox lost its connection is the most common reason a bill comes in higher than expected.
Frequently asked questions
Do I need a smart meter for an EV tariff?
Almost always, yes — the supplier needs half-hourly data to bill the off-peak rate.
What should I compare between tariffs?
The off-peak rate and hours, the day rate, the standing charge, and any export rate if you have solar.
Can I shift other appliances to the cheap window?
Yes, and you should. Dishwasher, washing machine and hot water on a timer multiply the saving.
Why was my bill higher than expected?
Usually a charge that ran outside the cheap window — a failed schedule, a lost connection or a car that did not accept the timer.