A charging tariff defines what a driver pays to use a connector. The simplest model is a single price per kilowatt-hour (PER_KWH), but real tariffs can combine several components: an energy price per kWh, a time price per minute, a flat session fee, and service charges, each possibly with its own VAT treatment.
Tariffs are volatile and network-specific. The same operator may price AC and DC differently, change prices frequently, and express whether VAT is included differently from its neighbours. This makes pricing one of the least standardized and most error-prone areas of charging data.
For any product that shows prices to drivers or reconciles charging costs for a fleet, tariff accuracy and provenance matter enormously: you need to know not just the number, but its currency, whether VAT is included, and when it was last observed.
In the Data for EV model
Data for EV models the Tariff as the fourth level of the canonical hierarchy, attached per connector, with currency, pricing_model, total_per_kwh, VAT treatment and itemized components — each value source-traced and timestamped so you know when it was observed.