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ev.energy API · Tariffs

Tariff builder

Describe a fixed-price tariff and get the request body for POST /v2/tariffs or PATCH /v2/tariffs/{tariff_id}, checked against the same rules as the API. Read Creating custom tariffs for how the API uses it.

  1. 1Prices
  2. 2Daily schedules: which price applies at each time of day
  3. 3Which days use which schedule

Start from…

Pick the closest match and adjust it. This replaces the prices, schedules and public holiday setting below but keeps your tariff details, and you can undo it.

1Prices

Every price the tariff charges, per kWh in pence, e.g. 7.5. Negative prices are allowed. Tick Off-peak for the cheap ones: charging summaries and the app label them that way. Names are only for this page.

pence/kWh
Used in Weekday, Weekend, Public holiday
pence/kWh
Used in Weekday
pence/kWh
Used in Weekend

2Daily schedules

A schedule sets which price applies at each time of day, in the tariff’s local time. Most tariffs need one, or two if weekends are different. Drag a divider on the bar to move it, or edit the times below.

Used: Mon–Fri.
Off-peak
Peak
to
to
or drag the dividers on the bar.
Used: Sat, Sun.
Off-peak
Weekend day
to
to
or drag the dividers on the bar.
For example, for weekends or summer months.

3Which days use which schedule

Choose a schedule, then click or drag across the calendar. Click a month or weekday heading to fill the whole row or column. Every day must have a schedule.

WeekdayMon–Fri
WeekendSat, Sun

4Public holidays optional

Off-peak
All day
or drag the dividers on the bar.
Which region’s holidays to use. The API checks the country and subdivision exist; this page only checks the format.

5Tariff details

Send user to assign the tariff to them; its currency, timezone and region then default to theirs. Without a user, send all three.

POST/v2/tariffs
✓ Ready to sendThe API also checks what this page can’t: that the currency and holiday region exist, and that you can use the user, region and supplier URLs.
{
  "name": "EV Saver",
  "supplier_tariff_id": "EVS-2026-10",
  "currency": "GBP",
  "timezone_name": "Europe/London",
  "user": "https://api.ev.energy/v2/users/user01HN2NJ9NMRZBXT1H6FT9N7735",
  "rate_periods": [
    {
      "months": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12],
      "iso_weekdays": [1, 2, 3, 4, 5],
      "rates": [
        {"start_time": "00:00", "end_time": "07:00", "price_minor_units_per_kwh": "7.5", "is_off_peak": true},
        {"start_time": "07:00", "end_time": "00:00", "price_minor_units_per_kwh": "24.5", "is_off_peak": false}
      ]
    },
    {
      "months": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12],
      "iso_weekdays": [6, 7],
      "rates": [
        {"start_time": "00:00", "end_time": "09:00", "price_minor_units_per_kwh": "7.5", "is_off_peak": true},
        {"start_time": "09:00", "end_time": "00:00", "price_minor_units_per_kwh": "18", "is_off_peak": false}
      ]
    }
  ],
  "public_holiday_rates": {
    "country": "GB",
    "subdivision": "ENG",
    "rates": [
      {"start_time": "00:00", "end_time": "00:00", "price_minor_units_per_kwh": "7.5", "is_off_peak": true}
    ]
  }
}