OCPI

Open Charge Point Interface: an open protocol for roaming between operators and e-mobility service providers.

Explained in

EV charging fundamentals · Stop 03What happens after you tap your card?Follow one tap from the card reader to the operator's backend and, for another company's card, across the roaming route and back. OCPP and OCPI in action.

OCPI connects companies: operators and card providers exchange card lists, tariffs, locations and session records.

From “Two protocols with two jobs”, stop 03

Also in

  1. EV charging fundamentals · Stop 08What standards make all of this work?Four standards, four connections
  2. EV charging fundamentals · Stop 09One charging session, fully understoodThe 22 minutes, narrated properly
  3. OCPP in depth · Stop 09One day of messages, fully understoodWhere to go from here
  4. OCPI and roaming · Stop 01Why does a card work at someone else's charger?Two roles, one session
  5. Plug & Charge · Stop 06Why does Plug & Charge not work everywhere yet?What helps
  6. Payments and billing · Stop 05How do roaming partners settle with each other?CDRs as the common basis
  7. Fleet charging · Stop 06How are charging costs tracked across a fleet?One view per vehicle
  8. Truck charging · Stop 06How are truck charging sessions planned and booked?A reservation in OCPI

Named in 8 further stops as well.

  1. RoamingCharging in another company's network with your own card or app.
  2. OCPPOpen Charge Point Protocol: the open protocol between a charger and its operator's backend.
  3. OICPOpen InterCharge Protocol: the roaming protocol of the Hubject platform.
  4. Roaming hubA platform that connects many operators and service providers, each through one connection.
  1. EVRoaming Foundation: Open Charge Point Interface (OCPI). https://evroaming.org/ocpi-background/. Checked 07 Oct 2026.