Getting two charging networks to work together is rarely as simple as flipping a switch. Location updates, tariff changes, authorizations, live session data, and billing records must all match on both sides. When they do not, the result is failed transactions, frustrated customers, and more support tickets.
OCPI provides operators with a common language for exchanging this data, eliminating the need to build a new integration for every partner. From 2.1.1 to 2.2, 2.2.1, and now 2.3.0, each version has addressed issues uncovered in daily operations. With 3.0 on the way, the protocol is set to introduce capabilities that could significantly change roaming management.
In this article, we break down the changes in each version and explain how they affect network reliability, efficiency, and scalability.
What is the OCPI protocol?
OCPI (Open Charge Point Interface) is a standard for how different electric vehicle charging networks share data with each other. It defines a common structure for exchanging information such as charging station locations, tariffs, status updates, session information, and billing records.
This standardisation means that charge point operators, eMobility service providers, and roaming hubs can connect without building a new custom integration for every partnership. OCPI works for both peer-to-peer connections between two networks and through roaming hubs that link multiple partners.
By using OCPI, operators can make their networks interoperable more easily, provide drivers with access to more charging points, and ensure that all parties have accurate, real-time data for authorisations, payments, and operational management.
The role of OCPI in the EV charging ecosystem
OCPI enables different charging networks to connect and share data consistently. This is essential for giving EV drivers access to more charging points without adding technical complexity for operators.
For charge point operators, OCPI reduces the work involved in setting up roaming with new partners by eliminating the need for custom integrations. For e-mobility service providers, it ensures that customers can locate charging stations, see live status updates, start and stop charging sessions, and pay, even when using a different network.
OCPI also supports automated roaming. Through roaming hubs, multiple networks can link together so that a single account works across many providers. This improves network reach for operators and gives drivers a consistent, reliable experience.
How does the OCPI protocol work?
OCPI is an API-based protocol, which means it uses defined endpoints and data formats in a way different systems can exchange information automatically.
Two main connection types are supported:
- Peer-to-peer: a direct link between two parties, such as a CPO and an EMSP.
- Hub-based: both parties connect to a roaming hub, which routes messages between multiple networks.
Through these connections, OCPI enables the exchange of:
- Token exchange for authorising drivers
- Tariff information for pricing transparency
- Session information and session data for active and past charging sessions
- Charge Detail Records (CDRs) for billing purposes and transaction records
- Static charge point information and status information for location and availability updates
How does OCPI work in practice?
Imagine an EMSP customer (a.k.a. an EV driver) starts a charging session on a CPO’s station in another network. At the same time, OCPI passes the token to authorise the driver, sends live status and energy usage back to the EMSP, applies the correct tariff, and returns the final CDR for billing, all in real time, without manual intervention.
OCPI modules, such as Locations, Sessions, CDRs, and Commands, define how each type of data is structured and transmitted. This standardisation allows charging networks to manage authorisations, track energy usage, send smart charging commands, and integrate with payment systems consistently across different providers.
OCPI vs. OCPP: Key differences
OCPP stands for Open Charge Point Protocol. It defines how a charging station communicates with its backend system. This is a charger-to-backend open protocol used for tasks like starting and stopping sessions, updating firmware, and sending meter values.
OCPI, on the other hand, is a network-to-network protocol. It governs how different EV charging networks exchange operational data such as locations, tariffs, authorisations, and session records.
In practice, OCPP handles the connection between a single charging station and its operator’s system, while OCPI handles roaming and interoperability between multiple networks.
The two protocols complement each other. For example, a CPO may use OCPP to control and monitor their charging stations, and OCPI to make those stations available to other networks through roaming agreements. This combination allows operators to manage their infrastructure while participating in a broader charging network.
Tl; Dr: OCPP = charger-to-backend protocol; OCPI = network to network protocol
OCPI version history and updates
OCPI 2.1.1
Released as an improvement over earlier versions, OCPI 2.1.1 focused on refining existing modules and improving interoperability between networks. Updates included clearer data structures, better handling of session information, and enhancements to tariff and location modules. These refinements made integrations more predictable, reducing errors during roaming and improving the consistency of exchanged data.
This version became the foundation for many live deployments and helped establish OCPI as a reliable standard in production environments.
OCPI 2.2
OCPI 2.2 introduced significant functional updates. It added support for multiple roles within a single platform, allowing an organisation to act as both a CPO and an EMSP under one implementation. The update also included enhanced roaming capabilities through better hub communication, improved energy management features, and expanded smart charging options, such as preference-based charging profiles.
Improvements to modules like Sessions, CDRs, Tariffs, and Locations increased flexibility and reduced integration gaps between different providers. These changes aimed to make complex roaming setups more reliable and easier to maintain.
OCPI 2.2.1
OCPI 2.2.1 was released to address minor issues and ambiguities discovered in 2.2. While not a major overhaul, it resolved small bugs, clarified documentation, and aligned implementations across networks.
Key changes included better consistency in how credit CDRs are handled, refinements to status information updates, and clearer rules for certain module interactions. For most operators, upgrading from 2.2 to 2.2.1 was a low-effort task that helped promote smoother interoperability.
OCPI 2.3.0
OCPI 2.3.0 was built on the stability of 2.2.1 and introduced new features aimed at expanding roaming capabilities. It improved station management, enhanced data for tariff information, and added refinements to support evolving business models and market demands.
While adoption is still ramping up, 2.3.0 offers better support for complex partner networks, improved session data handling, and additional energy management capabilities, making it more adaptable for future use cases.
OCPI 3.0 (Upcoming)
The upcoming OCPI 3.0 is expected to deliver a larger step forward. Planned features include support for Plug & Charge and Autocharge, expanded payment options including cryptocurrency support, deeper grid integration, and stronger data privacy compliance aligned with GDPR.
3.0 also aims to improve communication between CPOs, EMSPs, and drivers, streamline session credit management, and handle complex roaming migrations more efficiently. While still in development, it is positioned to support next-generation interoperability needs in the EV charging industry.
Which OCPI version is most popular and why?
OCPI 2.2.1 remains the dominant and most commonly used protocol version in production today.
- It's recognized for enhanced functionality, particularly smarter roaming and better smart charging.
- This version has become the current official standard, as confirmed by the EV Roaming Foundation, and continues to enjoy widespread adoption globally.
Why it’s popular:
- It addresses critical operational issues discovered after the broader rollout of 2.2, making implementations more robust.
- Roaming hubs, implementers, and market players continue leaning on 2.2.1 for stability and interoperability.
OCPI in the EV charging business
OCPI helps operators and service providers expand their charging networks without the complexity of building and maintaining separate integrations for every partner. A single OCPI implementation can connect a network to multiple partners, either directly or through roaming hubs.
This reduces integration costs, speeds up onboarding for new roaming agreements, and makes it easier to adapt to changing market demands.
For network operators, it means they can grow coverage quickly while keeping operational processes consistent.
Service providers benefit by offering their customers access to more charging points, reliable payment systems, and consistent session data across different networks. In competitive markets, OCPI gives EV charging businesses the flexibility to scale, form new partnerships, and align with efficient charging network models.
Benefits of OCPI for EV drivers and EV users
For drivers, OCPI removes the barriers between different charging networks. A single account can be used across multiple providers, making it easier to find charging points, start and stop sessions, and pay without signing up for separate services.
Allowing EV drivers to roam across networks increases convenience, especially on long trips where charging needs to be flexible. Access to real-time status information helps avoid out-of-service stations and reduces wasted time.
OCPI also supports features like smart charging, allowing drivers to choose the cheapest, fastest, or most environmentally friendly charging option available. When integrated with payment systems and payment terminals, it simplifies the entire charging process, from authorisation to billing.
Ultimately, OCPI improves network reliability and coverage for drivers, while giving operators and service providers the tools to deliver a consistent, user-friendly charging experience.
Challenges for implementing OCPI
While OCPI simplifies interoperability, implementing it still requires careful planning and resources. Technical teams need to be familiar with the OCPI documentation and ensure their systems can handle the required data formats and API workflows.
Integration with existing backend systems can be complex, particularly if those systems were not originally built with roaming in mind. Aligning with industry organisations and meeting compliance requirements, such as data privacy and security standards, is another essential step.
You should also consider long-term maintenance. OCPI evolves, and staying up to date with new versions is necessary to maintain compatibility with partners and roaming hubs. This means dedicating resources not only to the initial integration but also to ongoing updates and testing.
Choosing the right partners for implementation can reduce these challenges and make the process more cost-effective.
How to manage OCPI easily
Implementing OCPI from scratch can be resource-intensive, especially for teams balancing multiple priorities. Solidstudio’s OCPI Gateway is designed to simplify this process by providing a ready-to-use, fully compliant implementation of the protocol.
The gateway handles peer-to-peer and hub-based connections, supports all core OCPI modules, and is regularly updated to remain compatible with the latest official releases. This means operators can focus on running their networks rather than spending time on protocol maintenance.
With built-in monitoring, error handling, and version management, the OCPI Gateway reduces integration effort, shortens time to market, and ensures stable communication between partners. For businesses aiming to expand roaming capabilities without building and maintaining a complex integration in-house, it offers a cost-effective and reliable solution.
Bringing OCPI into your network
From OCPI 2.1.1 to 2.3.0 and the upcoming 3.0, each version of the protocol has aimed to solve real operational challenges in roaming. For operators, service providers, and roaming platforms, OCPI is now a core component of delivering reliable, scalable, and driver-friendly charging services.
If you want to expand your network coverage, streamline partner integrations, and reduce ongoing maintenance costs, Solidstudio’s OCPI Gateway can help you implement the protocol quickly and keep it running smoothly.
Book a call today to see how your business can benefit from a ready-to-use OCPI solution that’s built for long-term compatibility and growth.