OCPI (Open Charge Point Interface)

What is OCPI?

OCPI serves as the framework that lets EV charging operators connect, share information, and support roaming across platforms. OCPI pursues smarter, faster, and more cost-effective interoperability. It formalises message flows used by networks in ad hoc roaming collaborations and coordinates the standardization of business requirements for cross-network CHAT. Operators that adopt OCPI support a wider price and location database, forming a more transparent service for consumers.

OCPI is built around a common data framework that allows EV charging networks to exchange location, tariff, availability, and session data in a consistent way.

OCPI connects Charge Point Operators (CPOs) and Electric Mobility Service Providers (EMSPs) and allows them to share data via standard Application Programming Interface (API) endpoints. When enabling roaming, both sides add a partner to their systems and agree with a local operator. OP charges are applied at the local EMSP price to enable partner settlement, and online support is provided to partners. OCPI supports standardised data quality requirements across objects. Version management is also undertaken at the data level through a notification mechanism, streamlining adaptations and ensuring change compatibility across components linked to multiple operators.

How does it work?

As OCPI moves from specification into daily operation, its value lies in how efficiently networks exchange data and manage roaming workflows. The OCPI protocol implementation guide for CPOs and EMSPs is built around clearly defined data models, where each network remains the authoritative source for its own locations, connectors, tariffs, and sessions. At a functional level, the EV charging roaming protocol supports the following:

• Enables standardised data exchange for EV charging roaming between networks.
• Uses RESTful APIs with standard HTTP methods.
• Supports two interaction types:
  
  • Global data exchange for shared reference data.
  • Real-time interactions for live charging operations.

• Defines global data models for:
  
  • Locations
  • Connectors
  • Products
  • Sessions
  • Status updates

• Each network remains the authoritative source for its own data.
• Data changes trigger notifications to connected networks.
• Real-time interactions handle:
  
  • Session authorisation.
  • Session start and stop.
  • Roaming workflow execution.

This structure serves as a practical OCPI protocol implementation guide for CPOs and EMSPs by clearly defining data ownership, synchronisation, and real-time interaction flows.

How is OCPI used for EV Charging?

In real-world deployment, OCPI serves as the connective layer that enables diverse charging networks and service platforms to operate together smoothly and in coordination.

• Enables a single standardised connection between charging networks, rather than custom integrations for each partner.
• Allows operators using OCPI to interoperate once and support multiple use cases simultaneously.
• Primarily supports EV roaming, enabling drivers to charge seamlessly across partner networks.
• Helps roaming service providers partner with multiple charging networks via a single standard interface.
• Enables cross-network data access, including connector availability, pricing, and tariffs.
• Supports real-time and near-real-time information sharing without direct user involvement.
• Allows retail network customers to browse charging options transparently, even when third-party platforms operate in the background.
• Enables service providers to perform price comparisons and tariff analysis across participating networks.
• Reduces integration complexity while increasing network reach and service coverage.
• Improves driver experience by delivering consistent access, visibility, and pricing clarity across networks.

These capabilities form the technical basis for cross-border EV roaming in Europe and North America, where multiple operators and jurisdictions must interoperate seamlessly.

How OCPI Improves Interoperability?

OCPI improves interoperability by creating a common technical language that allows different EV charging networks to communicate and operate together without custom integrations.

• Standardises data models for locations, connectors, tariffs, and sessions across networks.
• Replaces bilateral, custom-built integrations with a single shared interface.
• Enables seamless roaming between charging networks using standard protocols.
• Allows networks to exchange real-time and reference data in a consistent format.
• Supports plug-and-play onboarding with new roaming partners.
• Reduces integration time and long-term maintenance effort for operators.
• Ensures consistent interpretation of charging status, pricing, and availability.
• Allows service providers to scale across regions without redesigning systems.

By improving visibility, pricing transparency, and charger availability, OCPI has a direct impact on reducing range anxiety for electric vehicle drivers.

Powering OCPI-Ready Interoperability with Exicom

As EV charging networks become more interconnected, smooth roaming and reliable data exchange are no longer optional. Exicom enables OCPI-compliant charging infrastructure and flexible backend integrations, enabling charge point operators and service providers to expand with ease. This approach lowers integration effort while ensuring a uniform charging experience across multiple networks. With interoperability built into both hardware and digital platforms, Exicom supports the development of EV charging ecosystems that remain open, scalable, and ready for the future, while keeping the driver experience at the core.

FAQs

Q: What is the difference between OCPI and OCPP?
A: OCPI vs OCPP is shown in the table below:

Q: Does OCPI allow for real-time pricing updates?

A: Yes, the OCPI 2.2.1 version includes enhancements that support near-real-time exchange of tariff and pricing data.

Q: Is OCPI a mandatory standard for EV chargers?

A: OCPI is not mandatory, but many networks adopt it to support roaming and interoperability across platforms.

Q: How does OCPI simplify billing?

A: By standardising session, contract, and tariff data, the Open Charge Point Interface standard reduces billing complexity between roaming partners.

Q: Can I use OCPI to reserve a charging station?

A: OCPI can indirectly support reservation-related workflows, depending on how the network implements session and roaming logic.