tariff
/ˈtarɪf/ noun- A list of the prices charged for a service.
- A price that changes with the time it is paid.
30 August 2026 · Amsterdam · 1 minute
The word came into English from Italian, and into Italian from Arabic taʿrīf, a notification. A tariff was a notice nailed up for traders: this is what it will cost.
1
Prices that move
A fixed tariff is a promise from the seller. A dynamic tariff is a forecast shared with the buyer. The second is fairer, and much harder to read.
Table 1
Table 1 shows a typical weekday in October.
Table 1 shows a typical weekday in October.
| Hour | Price per kWh | Compared with average |
|---|---|---|
| 00:00–06:00 | €0.14 | −42% |
| 06:00–10:00 | €0.27 | +12% |
| 10:00–16:00 | €0.19 | −21% |
| 16:00–21:00 | €0.36 | +50% |
| 21:00–24:00 | €0.22 | −8% |
The cost of a charge is then a sum over the hours it takes:
(1)
where is the price in hour and the energy drawn in it. The driver sees only . The software sees every term, and can move the large ones.
2
Reading it for someone
Nobody wants to read a price list before plugging in. The useful thing is a sentence: ready by seven, about four euros. Everything in the table above is still there, folded into the choice of when.