Smart Charging Tariffs: When the Supplier Controls the Charger

A smart charging tariff is an electricity deal where the supplier does more than charge you less at night: it takes some control of when your car actually charges. On the best-known example, Intelligent Octopus Go, the supplier schedules your charging in exchange for off-peak rates of around 7 to 9p per kWh, applied to up to six hours of smart charging every 24 hours¹. The cheap window sits overnight, with off-peak rates as low as £0.07/kWh from 23:30 to 05:30³.

The trade is simple and worth stating plainly. You hand the supplier the ability to decide when your car draws power, and in return your motoring electricity costs a fraction of the household rate. The supplier needs a smart meter to measure your use half-hourly, and usually a link to your charge point or your car itself to do the scheduling. Both halves of that arrangement, the cheap rate and the loss of direct control, are covered on this page.

When your energy firm manages the charging

A time-of-use tariff on its own does not control anything: it simply charges different rates at different times, and it is up to you to shift your consumption into the cheap windows. A supplier-controlled smart charging tariff goes a step further. The supplier, or its software, sends instructions to your charge point or to your car, telling it when to start, when to pause and how fast to charge, so that the energy arrives when it is cheapest for the supplier to buy.

The legal footing for this is worth understanding. Except by switching, you do not control the tariff your energy supplier sets, but you can change how much energy you use and when⁷. The supplier, in turn, needs your data to operate the arrangement: smart meter data is used to bill you for the energy you use, to offer new products and services such as new tariffs where you have given permission, and to help make the energy system more efficient by recording demand more accurately⁸.

There are also rules on the charger itself. Under the regulations for smart charge points, a charge point must be configured to operate a default randomised delay of up to 600 seconds, 10 minutes, at each charging instance, and the default hours must be pre-set to not charge during times of peak electricity demand, between 8am and 11am and 4pm and 10pm on weekdays⁹. These defaults exist to stop thousands of chargers switching on at the same moment and stressing the local network, and they can be overridden by the user.

The reason suppliers want this control at all is network-wide. Some suppliers already offer smart meter-only tariffs and smart time-of-use tariffs, because half-hourly data lets them price electricity closer to what it actually costs to buy and move¹⁰. Some of these tariffs are only available if you have certain equipment installed, such as an EV charger or solar panels¹¹. Your car battery, seen from the supplier's side, is a flexible load it can place in the cheapest hours of the night, and that is precisely what it does.

Intelligent Octopus Go: 7 to 9p per kWh in a six-hour window

Intelligent Octopus Go is the tariff most people mean when they talk about supplier-controlled charging. It offers off-peak rates of around 7 to 9p per kWh for EV charging, against peak rates on comparable EV tariffs of around 28.69p/kWh¹. The headline structure is up to six hours of super-cheap smart charging every 24 hours, for EV charging only².

The scheduling is more flexible than the fixed window suggests. Your six hours of super-cheap smart charging can be scheduled during the 11:30pm to 5:30am off-peak window, outside that window, or across a mix of the two². That is the practical difference between this tariff and a classic night-rate deal such as Economy 7: the supplier is not giving you a fixed cheap block and hoping you use it, it is placing your six discounted hours wherever they best fit its own buying, using the target charge level and ready-by time you set.

In practice you keep two controls: the target charge level, how full you want the battery, and the time you need the car ready by. The supplier's system works out when to charge within that envelope. If it needs to charge outside the standard window to hit your target, it can, and the discounted rate still applies to those scheduled hours². What you give up is the ability to decide the exact half-hours yourself, which is the whole point of the arrangement and the source of both the savings and the frustrations.

Exceeding the six-hour cap: the consequences

The six hours are a daily allowance, not a rolling bank. Once your six discounted hours are used, any further smart charging is billed at the peak rate, even if it happens overnight². So a car that needs more than six hours of charging in one night does not lose its cheap rate on the first six hours, but everything beyond that is charged at the full rate, in the middle of the night or not.

This is where the arithmetic of charger power matters. Six hours at a typical home charge rate is a substantial charge, and for most cars most nights it is ample. But a very flat battery, a cold night with the car preconditioning, or a larger EV with a big battery can push past the allowance, and the bill reflects it. The same principle appears on other supplier-controlled tariffs in different forms: on OVO Charge Anytime, any charging beyond the monthly allowance is billed as normal home electricity use, at the unit rate on the customer's home energy tariff¹².

There is always an escape hatch, and it always costs. A manual override starts charging immediately at the fastest possible rate until the EV is full, does not use smart scheduling, and is always billed at the peak or standard rate². The same fallback applies if the charger is offline when you plug in: charging starts anyway, at the peak rate, because a charger that cannot receive instructions cannot claim the discounted ones². The cheap rate and the supplier's control are two sides of one coin, and the billing rules make sure of it.

Matching your charger to your tariff

Not every charger can take instructions from every supplier, and this is the single biggest practical hurdle when joining a supplier-controlled tariff. Compatibility is a matter of specific integrations, not a general standard, so the tariff's own list of supported hardware is the authority.

The clearest example of a full integration is the Andersen A2. As of September 2025, Andersen A2 chargers are integrated with Intelligent Octopus Go, with the exclusion of 22kW units¹³. Andersen also states its range of charge points is compatible with popular EV smart charging tariffs such as OVO Charge Anytime¹³. At the other end of the spectrum, the Ohme ePod is described by its maker as compatible with all energy tariffs⁶, and an independent comparison lists the Andersen Quartz as smart tariff compatible¹⁴.

The waEV-smart tariff takes the opposite approach and illustrates the boundary clearly: supplier-controlled smart tariffs like Intelligent Octopus Go and OVO Anytime are not compatible with it, because they already control your charging¹⁵. Two systems issuing conflicting schedules to one charger is the failure mode every tariff tries to avoid, which is why a tariff that controls charging itself will ask you to switch off any price-cap or self-scheduling feature on the charger first.

A summary of where the main hardware stands:

Some tariffs are only available with certain equipment installed, such as an EV charger or solar panels¹¹, so the order of decisions matters: pick the tariff and the hardware together, not one after the other. Our page on EV tariffs sets out the wider market, and the comparison of Intelligent Octopus Go vs Octopus Go shows what changes when the supplier takes control.

Ohme ePod, Home Pro and Andersen A2: specs and cost

Three charge points cover most of what UK buyers weigh up when a supplier-controlled tariff is in view. The Ohme ePod is an untethered unit, with no cable attached, that works with Type 1 or Type 2 connectors, making it what the maker calls a universal charging companion whatever connector your EV uses¹. The Ohme Home Pro is tethered, with a cable permanently attached so it is always on hand¹. The Andersen A2 is fitted with a hidden tethered charging cable, housed inside the unit's body¹³.

On price, the published position is thin, and that is worth saying plainly. At the time of an independent comparison, the Home Pro cost only £50 more than the ePod¹⁴. Beyond that, prices for all three are installer-quoted, because the final figure depends on the cable run, the consumer unit and the work involved, so treat any headline price as a starting point and get written quotes. The Andersen A2's made-to-order construction and wide choice of finishes put it in a different category of product, and no published price is available for it.

The Andersen A2 can also be configured for three-phase power, depending on your home's electricity supply¹³, which matters only for the small minority of homes with a three-phase connection. For everyone else the practical differences are the cable arrangement and the look: an untethered unit like the ePod suits households happy to keep a cable in the boot, a tethered unit like the Home Pro or A2 suits those who want to plug in without fetching anything.

The real savings in numbers

The official numbers are substantial. Government analysis of distribution networks found that an average-consumption household with an EV could already save around £330 annually by smart-charging on a time-of-use tariff when compared to a static one⁴. A parliamentary committee report put the same point more broadly, noting that some innovative energy suppliers were able to offer tariffs, to consumers with smart meters, that could save up to two-thirds of the costs of charging electric vehicles if charging at certain times of day¹⁶.

The per-session arithmetic shows where the money goes. Charging a 7kW wallbox during the off-peak window can add around 28kWh for just £1.96, while at peak rates of around 28.69p/kWh the same charge could cost £22.29 or more³. Ohme, speaking as the maker, claims that for most EV drivers this adds up to £500 or more in savings each year simply by charging smarter with Ohme¹, a figure that assumes a high annual mileage and consistent use of the cheap windows.

Two caveats keep the picture honest. First, the savings depend on the price gap between the tariff's peak and off-peak rates, and on your discipline in keeping household use out of the expensive hours, which is its own skill: see shifting electricity use to cheap rates. Second, public charging is a different market entirely. Smart charging tariffs make it cheaper to use electricity at night or at times of low electricity demand¹⁷, and services such as Zapmap Premium offer a 5% saving on the cost of public charging¹⁸, but a public rapid charger will never match an overnight home rate, which is why the case for a home charge point rests on the tariff behind it.

Using solar and load balancing with a smart tariff

A supplier-controlled tariff and a solar array can work together, but the interaction needs understanding. Smart chargers can monitor real-time solar electricity production and adjust charging speed accordingly, drawing more or less power as generation rises and falls, and switching between solar and grid supply depending on availability¹⁹. The Ohme ePod's Solar Boost feature works this way, using the solar energy excess to charge the car⁶, and the Home Pro lists home power balancing among its smart features⁶.

The network industry's own strategy documents make the connection explicit: smart charging can enable the leverage of time-of-use tariffs²⁰. In a solar home the logic runs in two directions. The charger can be set to prefer your own generation, which is the cheapest electricity there is, and the household battery, if there is one, can be set to charge up when electricity is cheap and to discharge when electricity is expensive²¹.

Solar-specific energy tariffs usually combine an export tariff with a smart time-of-use tariff, with different electricity prices based on peak and off-peak times²². Some smart tariffs go further and pay you to use up excess energy when there is more electricity being generated than can be stored²³. Energy Saving Trust's picture of the energy-efficient house of the future has the home using a smart time-of-use tariff and an export tariff together²⁴, and for homes with solar panels and a battery the recommended options are a dedicated solar/battery tariff, or a good Smart Export Guarantee tariff matched with a dynamic import tariff or an Economy 7 tariff²¹.

The practical tension is that a supplier-controlled charging schedule does not know about your clouds. A tariff that has decided to charge your car at 2am will do so whether or not your panels produced a surplus at noon, unless the charger's own solar features or your battery settings intervene. Households running both usually let the charger's solar monitoring shape the daytime charging and leave the supplier's schedule for the overnight top-up. Our page on EV tariffs with solar and a battery works through the combinations.

Getting started: meter, connection and month one

The entry requirement comes first. A smart meter, or a willingness to have one installed, is a condition of getting an EV tariff⁵, and the same rule applies to smart time-of-use tariffs generally²⁵. Smart meters are optional, but households without one do not get the easier billing and innovative tariff options that come with them²⁶. Anyone who pays for their energy, whether they own or rent their home, can book a smart meter installation where it is expected to work in the property²⁷. The standing charge paid depends on the tariff and energy supplier, but not on whether a smart meter is installed²⁸, so the meter itself is not a cost risk.

For households wanting to go further and earn flexibility payments, a smart meter is needed in most cases, plus being on a smart tariff, and suppliers can arrange free installation²⁹. The data the meter shares is used to bill you, to offer new products and services such as new tariffs where you have given permission, and to help make the energy system more efficient by recording demand more accurately⁸.

Then comes the link. Joining a supplier-controlled tariff means connecting either the charge point or the car to the supplier's platform, which is why compatibility, covered above, decides which route you take. Expect a short wait between signing up and the link going live, because these onboarding processes are not instant even on the installer side: under the domestic charge point grant scheme, an installer's application to appear on the eligible installer list can take up to 15 days³⁰. Some suppliers sweeten the early weeks, with incentives such as a £20 welcome credit after your first 30 days of smart charging on waEV-smart¹⁵.

A checklist for the first month:

1. Confirm the smart meter is installed and communicating before the tariff starts.
2. Check the tariff's supported list for your exact charger model and car.
3. Disable any price-cap or self-scheduling feature on the charger, since supplier-controlled tariffs are not compatible with them¹⁵.
4. Set your target charge level and ready-by time, and check the app the next morning to see where the supplier actually placed the hours.
5. Watch the first bill or in-app statement to confirm the discounted hours are being billed at the off-rate.

Supplier control and your freedom at home

The independence ledger for a supplier-controlled tariff has entries on both sides, and it is better to see them clearly before signing up than after.

On the benefit side, the tariff converts your car into a cheap-to-run asset and reduces what you pay to the wider electricity market for motoring. The savings are real and official, around £330 a year for an average-consumption household smart-charging on a time-of-use tariff⁴, and the cheap hours can be placed flexibly around your ready-by time². A home with solar and a battery can go further still, charging the car from its own generation and using the tariff only for the overnight remainder¹⁹.

On the dependence side, the list is longer than it first appears. You depend on the supplier's software to schedule your charging, on the charger's connection to receive those instructions, and on the app to tell you what is happening: the Home Pro, for instance, keeps its link through a 3G / 4G multi-net SIM card⁶, so a network outage means the smart schedule stops and charging falls back to the peak rate². You depend on the supplier's commercial decisions too: except by switching, you do not control the tariff your energy supplier sets⁷, and the same asymmetry runs through export payments, where electricity suppliers determine the tariff they are willing to pay to small-scale generators³¹. A tariff's rates, its six-hour allowance and even its availability can change with the supplier's economics, not yours.

The honest summary is that a supplier-controlled tariff buys cheap electricity with a measure of control. The car still charges, the override always works, and you can leave, but while you are in the arrangement the supplier decides the half-hours. For many households that is a good trade, and for households that want to keep the decisions themselves, a plain time-of-use tariff with self-scheduled charging, or a solar-and-battery setup that minimises grid use altogether, keeps more of the control at home³². That choice, between cheap rate and self-determination, is what tariffs and household energy independence come down to.