How is a roaming card authorised?

Either from a cached list the provider shared with the operator, or by a real-time check with the provider. The provider sets which, per token.

Explained in

OCPI and roaming · Stop 04How does a token reach the charger?Cached token lists or real-time authorisation: the four whitelist types of OCPI, and what each one means when the driver taps the card.

A cached token is fast: the operator already knows it and can accept it at once. A real-time check gives the provider control, for example over a blocked card, but it takes longer, which OCPI notes can mean a less pleasant wait at the charger.

From “Speed against control”, stop 04

Terms

  1. OCPIOpen Charge Point Interface: an open protocol for roaming between operators and e-mobility service providers.
  2. TokenIn OCPI, what a driver starts a session with, such as a charging card, a key fob or an app account; it carries the contract ID of the driver's provider.
  1. What does OCPI exchange?Locations and tariffs from the operator, tokens from the provider before a session; sessions and commands during it; the CDR after it.
  2. What is a roaming hub?A platform that connects many operators and providers through one link each. Many organisations use OCPI in a hybrid way, with hubs and direct connections side by side.
  3. Can a CDR be changed after it was sent?Not directly. OCPI treats CDRs like invoices: a wrong CDR is cancelled with a credit CDR and replaced by a corrected one.
  4. What is in a CDR?Who wrote it, the token that started it, the one EVSE used, the tariff as it applied, the session as periods with energy and time, and the totals before taxes. The deep dive reads a complete record line by line.
  1. EVRoaming Foundation: OCPI 2.3.0, Tokens module: whitelist types and real-time authorisation. https://github.com/ocpi/ocpi/blob/2.3.0/release/core/mod_tokens.asciidoc. Checked 09 Oct 2026.