How do smart charging and off-peak tariffs work for businesses?

Smart charging can move electricity use into your contracted cheaper periods, provided vehicles remain plugged in long enough. The private chargepoint rules took effect on 30 June 2022 in Great Britain [S1]. They do not establish your business tariff's hours or prices. Compare the whole electricity bill and test departure readiness before changing schedules. Checked October 2026.

Last checked 16 October 2026

What is smart charging at a business site?

Smart charging changes when, or how quickly, a vehicle charges in response to control signals. The government action plan describes time-of-use tariffs as rewarding consumption when electricity is cheaper or renewable generation is plentiful [S2]. Your actual opportunity depends on your contracted rates and vehicle availability.

Kilowatts, or kW, measure charging power. Kilowatt-hours, or kWh, measure the energy delivered. A timer can move energy to another period, while a power limit controls the rate at which your site draws electricity. Those are separate settings. Set both around your operating requirement.

Start with a departure schedule and energy requirement for each vehicle. A depot van parked overnight may have room to wait. A customer’s short visit may not. Do not promise staff a departure charge until the proposed timetable has been checked against simultaneous demand and the vehicle’s own charging controls.

When are your business electricity tariff’s off-peak hours?

Read the contract’s rate schedule and ask your supplier to confirm the metering arrangements in writing. The smart chargepoint rules require default off-peak settings, but those settings are not a quotation for your electricity [S1]. The action plan likewise describes a tariff-linked opportunity, not a universal cheap rate [S2].

Build a comparison sheet before switching. Request the day rate, cheaper-period rate, standing charges, capacity charges where applicable, contract length and any service subscription. Confirm whether the cheaper period applies to all metered consumption or only identified charging. Do not import a domestic EV tariff advertisement into a commercial budget.

Check clock changes and the contract’s definition of time when setting schedules. Save the agreed rate sheet with your commissioning record. Ask who will update the charging schedule when your electricity contract changes, and name a person at your site who can approve that update.

How much could off-peak charging change your electricity cost?

Use your actual contract for a decision. The following is an illustration, not a quote. Every price and usage input is an assumption; none represents an available tariff. All figures exclude VAT and other bill items.

The flat-price calculation is 100 × 250 × £0.25 = £6,250. The time-of-use calculation is 25,000 × (80% × £0.15 + 20% × £0.30) = £4,500. The illustrative difference is £1,750 a year before other costs. It is an energy-cost comparison, not charging profit or an equipment payback claim.

Now assume the rest of your site uses 40,000 kWh during the daytime period. The assumed 5p higher day rate adds 40,000 × £0.05 = £2,000. That would outweigh the charging difference, before subscriptions or standing charges. This is why the whole-site bill matters more than the advertised overnight unit price.

Can your vehicles finish charging within the cheap window?

Use an illustrative fleet requiring 100 kWh during an available 5-hour window. Its average requirement is 100 ÷ 5 = 20 kW before losses. If only 12 kW is allocated to charging, that window supplies at most 12 × 5 = 60 kWh before losses. The remaining requirement needs another charging period or a revised plan.

These are assumed inputs, not a suggested electrical design. Ask your installer to model late arrivals, urgent departures and the site’s other demand. Require a report that shows energy delivered by departure, rather than only the charging station’s headline rating.

Use dwell time and charger speed to set the operational target. Use dynamic load management to explore sharing capacity. Neither an app nor an electricity contract replaces an assessment of the incoming connection.

Which rules and commissioning checks should you use?

The private smart chargepoint rules cover relevant domestic and workplace devices sold for use in Great Britain. Northern Ireland and rapid or public chargepoints are outside that particular scope [S1]. For public operation, check the public chargepoint rules [S3].

Request a demonstration before acceptance:

• Plug in outside the scheduled window and confirm the expected waiting behaviour.
• Start an urgent charging override and confirm the site power limit remains effective.
• Compare the vehicle timer, charger timer and any central controller to identify conflicts.
• Disconnect communications under the installer’s supervision and record the outcome.
• Review a charging log alongside the meter data and the contracted rate schedule.

Record who owns each setting. Where an installer supplies a separate software service, ask for subscription, support, data access and cancellation terms. Our smart chargepoint regulations guide explains the device requirements separately from the commercial service you buy.

What should you do next?

Bring your tariff sheet, consumption data and vehicle departure requirements, then get matched with an installer that covers your area. Ask for a proposed schedule and a whole-site cost comparison using your own inputs.

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