The Complete OCPP Guide

Key takeaways

• The Open Charge Point Protocol (OCPP) is a widely adopted manufacturer-neutral standard for communication between electric vehicle (EV) charging stations and central management systems. Originating in 2009, it has evolved through multiple versions, with OCPP 2.1 (released January 2025) introducing backward compatibility and Vehicle-to-Everything (V2X) support.
• OCPP’s core purpose is to prevent vendor lock-in and enable interoperability, allowing charging stations from different manufacturers to communicate with various central management systems. The protocol operates on a client-server architecture, facilitating real-time data exchange for authorization, transaction processing, and status monitoring.
• OCPP facilitates authorization, transaction processing, smart charging, firmware management, and remote diagnostics. Despite challenges such as version migration and implementation quality, OCPP’s standardization delivers measurable benefits. Among them are increased uptime, lower integration costs, and faster transaction processing, making OCPP indispensable for the maturation and scaling of EV charging infrastructure.
• The protocol’s ecosystem includes Charge Points, Charging Station Management Systems (CSMS), Charge Point Operators (CPOs), and eMobility Service Providers (eMSPs). Security is a critical aspect, with defined profiles and a certification program ensuring implementations meet rigorous standards.

1. What is Open Charge Point Protocol (OCPP)?

The Open Charge Point Protocol, OCPP, is an open-source protocol that facilitates smooth communication and management of EV charging infrastructure.

It enables interoperability between various EV charging equipment and central management systems, regardless of the manufacturer or type of charging station. With OCPP, charge point operators can remotely monitor their charging stations, authorize access, configure hardware, update firmware, and integrate different payment and billing systems.

2. A short history of OCPP and how it has evolved over time

OCPP was first developed by the Dutch company E-laad in 2009 in collaboration with several other organizations in the EV industry, notably Logica and Alfen.

The initial version of OCPP, OCPP 1.0, was released in 2010 and focused on providing basic communication between EV charging stations and EV charging management systems.

In 2013, the E-laad Foundation in the Netherlands, Greenlots in North America, and ESB in Ireland joined forces to establish the Open Charge Alliance (OCA), a worldwide consortium of EV infrastructure experts from both public and private sectors. The OCA’s primary goal was to encourage the widespread adoption of a standardized communication protocol, OCPP.

Over the years, OCPP has continued to evolve with new releases, including OCPP 1.2 (2012), followed shortly by OCPP 1.5 (2012), which saw broader adoption, and later OCPP 1.6 (2015), the most widely used version. More recent updates include OCPP 2.0 (2018) and OCPP 2.0.1 (2020). With each new release, OCPP has introduced enhanced features and capabilities, such as support for different types of charging stations, smart charging functionality, and improved security.

Open Charge Point Protocol is now widely adopted and recognized as the industry standard for communication between EV charging stations and management systems.

3. The benefits of OCPP

These are the six main benefits of using OCPP as a communication protocol for EV charging. OCCP-powered software brings the following advantages:

1. Interoperability and compatibility: OCPP enables EV charging equipment from different manufacturers to communicate with EV charging management systems and with each other, regardless of the specific hardware or software used. This gives operators the flexibility to mix and match charging stations and scale their networks without compatibility constraints.

2. Improved management and monitoring: OCPP enables remote monitoring, control, and management of EV charging stations. Operators can start and stop charging sessions, track energy consumption and billing, and troubleshoot issues in real time.

3. Enhanced customer experience: OCPP enables operators to manage customer accounts and billing and offer a range of payment options, making it easier for customers to use charging stations. By leveraging OCPP technology, AMPECO aims to provide better and more intuitive driver apps that simplify the process of finding, accessing, and paying for EV charging services. 

4. Cost savings: OCPP helps network operators reduce operational costs by minimizing manual maintenance and improving charging session efficiency. It also enables access to detailed usage data, such as charging duration and time-of-use patterns, which can be used to refine pricing strategies and tailor tariffs to different user groups. In addition, OCPP supports dynamic pricing, allowing operators to adjust rates in real time based on demand, energy costs, and grid conditions, maximizing both utilization and revenue.

5. Future-proofing your network: OCPP is an open-source protocol that continues to evolve and improve. It’s robust security features, such as encryption and authentication, protect against unauthorized access or data tampering. This way, EV charging infrastructure remains up-to-date and compatible with new technologies and standards.

6. Smart charging capabilities: OCPP enables smart charging by allowing operators to dynamically control how and when EVs are charged based on grid demand, energy availability, and pricing signals. This helps balance grid load, optimize energy usage, and reduce charging costs for both operators and drivers.

4. How OCPP works

OCPP provides a standardized protocol for communication between EV charging stations (also called Charge Points) and a central management system (also called the Central System). The protocol enables the EV charging stations and central backend systems to exchange messages and data with each other. There are also other protocols that are either being used or developed that work alongside OCPP that handle communication between charging stations and EVs.

The Open Charge Point Protocol defines two roles:

The Open Charge Point Protocol defines two roles:

Charge Point (or the client): The physical EV charging station where an electric vehicle can charge. A Charge Point will have one or more connectors. It provides information about the availability and status of charging sessions and energy consumption.

Central System (or the server): The charge point management system (CPMS) communicates with the Charge Point using OCPP to monitor and manage charging sessions and collect data on energy consumption and billing.

OCPP implementation types

There are two main types of OCPP implementations:

SOAP/XML: Simple Object ACESS Protocol (SOAP) is a message-based protocol that uses XML to represent data. XML is a bulky format, compared to modern formats like JSON, making it less suitable for EV charging stations with unreliable internet connectivity. The size of the XML messages can cause delays and timeouts, which can be a problem for real-time communication.

In OCPP implementations using SOAP, both the Charge Point and the central system typically need to support incoming connections, which can complicate network configuration. This makes deployment and scaling more challenging, particularly when devices are located behind NAT or firewalls, often requiring additional setup such as port forwarding or public IP addresses.

JSON: JavaScript Object Notation (JSON) is a lightweight and flexible data interchange format that is easier to read and write than XML. It also has much better diagnostics capabilities. Receiving and sending data with JSON is simple as it uses HTTP requests. It relies on a websocket for two-way communication, which requires only one entity to act as a server, which in OCPP’s case is the backend.

5. The main OCPP terms

OCPP profiles are an essential component of the Open Charge Point Protocol (OCPP) standard. They define how charging stations and management systems communicate with each other.

OCPP profiles specify the messages exchanged, their formats, and the functionality and behavior supported by each system.

Additionally, OCPP profiles use specific data types to define the format and structure of data transmitted between the charge point and the central management system. Configuration keys control various settings during a charging session, while use cases describe desired behavior during different stages of a session.

Finally, predefined test cases help developers ensure the protocol is implemented correctly.

Each OCPP term is described in detail below.

Profiles

OCPP profiles define how charging stations and management systems should communicate with each other, including the messages exchanged, the format of these messages, and the specific functionality and behavior supported by each system.

In OCPP 1.6, the most popular version of the protocol in 2026, features and associated messages are grouped in profiles. Depending on the required functionality, implementers can choose to implement one or more of the profiles.

Customers can use these profiles to determine if an OCPP 1.6 product has the required functionality for their business case.

The list of profiles includes:

• Core Profile
• Firmware Management Profile
• Local Auth List Management Profile
• Remote Trigger Profile
• Reservation
• SmartCharging

OCPP 2.0.1 introduces the ChargingProfile, which defines how charging power is managed over time. It includes a ChargingSchedule that specifies the amount of power or current delivered at different time intervals. Together, they determine how quickly a vehicle charges and how energy is distributed throughout the charging session.

ChargingProfiles can be defined by external systems such as a CPMS or an energy management system.

Message

A message refers to a data unit transmitted between a charge point (CP) and a central management system (CMS) during a charging session. Each message has a specific format and purpose and multiple messages may be exchanged during a charging session.

Data type

OCPP profiles use specific data types to define the format and structure of data that is transmitted between the CP and CMS. These formats include common data types such as string, integer, and boolean, as well as more specialized data types such as date-time and enumeration.

Configuration keys

Configuration keys define various settings and parameters that control the behavior of the CP during a charging session. These settings can include:

• Charging rates
• Maximum power limits
• Authorization requirements

Each profile includes a set of predefined configuration keys, which can be modified by the CP or CMS as needed. However, some of these keys can only be configured by the CP and cannot be changed with the ChangeConfiguration message.

Use case

The use case refers to a specific scenario or behavior that the Open Charge Point Protocol is designed to support. Each case describes the desired behavior of the CP and CS during various stages of a charging session. Examples of use cases include start transaction, stop transaction and remote start transaction.

Test case

Test cases are used by developers to ensure that the OCPP protocol is implemented correctly.

Each OCPP profile includes a set of predefined test cases that developers can use to verify the implementation’s behavior. These test cases cover various scenarios and edge cases to ensure robust and reliable implementation of the Open Charge Point Protocol.

6. The Functional Blocks of OCPP

OCPP 2.0.1 is divided into several Functional Blocks, each containing a set of use cases and requirements for that block. The main Functional Blocks of OCPP include:

7. A quick overview of the versions of OCPP

OCPP 1.5

Although OCPP 1.5 was standardized in 2012 and widely adopted, different implementations of the protocol led to interoperability issues, with some implementations being partially incompatible. As a result, the Open Charge Alliance only certifies OCPP compliance starting with OCPP 1.6, even though it adheres to the core content of OCPP 1.5.

OCPP 1.6

OCPP 1.6 introduces additional functionality, including smart charging, which enables both local and central load balancing, as well as support for JSON messaging and on-demand information retrieval through trigger messages.

OCPP 1.6 supports secure communication using transport-level encryption (e.g., TLS). However, it does not provide a comprehensive, built-in security framework such as certificate lifecycle management and advanced security features introduced in later versions.

To achieve higher levels of security, additional measures such as private networks, VPNs, or IPsec connections may be implemented.

OCPP 2.0

When OCPP 2.0 was first introduced in April 2018, some issues were discovered that couldn’t be resolved by simply fixing textual nuances in the documentation. Instead, significant changes were required, rendering it non-backward compatible with its predecessors.

Compared to earlier versions, OCPP 2.0 represents a significant redesign of the protocol, with almost all messages being different and a host of new functionalities added. Despite this lack of backward compatibility, this version boasts significant functionality, security, and interoperability improvements.

For instance, OCPP 2.0 supports bidirectional power transfer allowing vehicle-to-grid (V2G) applications where the EV battery can supply energy back to the grid. Additionally, enhanced security features and better interoperability with other protocols have been introduced.

OCPP 2.0.1

OCPP 2.0.1 was released in 2019. Its primary objective is to resolve bugs and inconsistencies in OCPP 2.0 while providing more clarity on specific aspects of the protocol. Compared to OCPP 1.6, OCPP 2.0 and 2.0.1 introduce several major changes:

Device Management

This feature was highly anticipated by Charge Point Operators who manage complex, multi-vendor (DC) charging networks. It provides detailed information regarding charging stations to the software management platform, enhances charger visibility, and makes it easier to operate and maintain the chargers in your network.

Improved Transaction handling

Transaction data reporting was split over several messages in previous protocol versions. But reducing the amount of data has become increasingly important to CPOs who manage numerous stations and transactions. In OCPP 2.0.1, the structure and method for reporting transactions are unified, reducing the amount of data as a whole.

Enhanced security

The data packets are now encrypted at the protocol level and do not require a VPN or any third party for a secure connection. This makes it difficult for unauthorized parties to intercept and access the transmitted information. OCPP 2.0.1 also added secure firmware updates, security logging and event notification, security profiles for authentication (key management for client-side certificates), and secure communication (TLS).

Extended Smart Charging functionalities

A significant improvement in OCPP 2.0.1 is the possibility for the EV to communicate the requested energy amount in kWh. EV charging management systems can now accurately view the energy (kWh) each EV needs and set the smart charging output accordingly, allowing for more grid-friendly, secure, and convenient EV charging.

Support for ISO 15118

OCPP 2.0.1 has native integration with ISO 15118, allowing for new features and more secure communication between EVSE and EV. The newly added features are:

• Plug & Charge
• Smart Charging, including input from the EV

Improvement in display and messaging:

OCPP 2.0.1 allows charge point operators to configure messages from their EV charging management platform that can be displayed to drivers on the charging stations.

These include display messages:

• in the preferred language of the EV driver,
• that show the applicable tariff before a driver starts charging,
• that show the running cost during a charging transaction and the final total cost.

8. The main use cases for OCPP

OCPP enables a wide range of use cases that support the operation, management, and optimization of EV charging infrastructure. Here are the main use cases for the protocol:

Remote connectivity and management of charging stations

OCPP allows EV charging network operators to remotely monitor and manage their charging stations, enabling them to stay on top of their operations from any location. Through OCPP, the CSMS can receive detailed data from Charging Stations, including meter values (e.g., voltage per phase) and status notifications. This data supports operational monitoring, maintenance, and optimization of charging networks.

In addition, external stakeholders, such as DSOs or utility companies, can use this data for monitoring and grid management. The availability of detailed measurements provides insights similar to smart metering, improving operational efficiency and visibility.

Using OCPP to enable smart charging and load management

OCPP enables Smart EV charging by aligning EV charging energy demands with available grid capacity. This ensures that power is distributed evenly across individual charge points, sites, and the grid itself, reducing the burden on the grid during peak demand periods.

Smart charging can be applied at multiple levels, including the EVSE (outlet), station, or group/location, enabling flexible load management strategies based on grid conditions and local constraints. The CSMS receives charging data and dynamically adjusts charging behavior by sending charging profiles to Charging Stations. These profiles define parameters such as power or current limits based on dynamic load management principles.

Using OCPP’s smart charging modules, a unique charging profile can be created for each charger at a given site, enabling optimized and efficient energy usage across the network.

Integration with other protocols

OCPP is designed to integrate with other communication protocols, enabling interoperability and extending the capabilities of EV charging systems.

Two important protocols commonly used alongside OCPP are ISO 15118 and OpenADR.

ISO15118

ISO15118 is a communication protocol that enables Plug&Charge functionality and Vehicle-to-Grid (V2G) capabilities.

• Plug&Charge allows an EV to automatically identify and authorize itself to a compatible charging station on behalf of the driver using digital certificates, eliminating the need for drivers to carry multiple payment cards or use mobile apps to access charging stations.
• Vehicle-to-grid (V2G)  facilitates two-way energy transfer between EVs and the grid, enabling a more efficient and sustainable energy ecosystem. V2G technology enables EV batteries to be used as energy storage devices, providing a valuable resource for the grid during peak demand periods.

OpenADR

OpenADR (Open Automated Demand Response) is a communication protocol that allows utilities and grid operators to send signals to energy-consuming devices to manage electricity demand during times of peak usage or supply shortages.

When integrated with EV charging infrastructure, these signals can be used by the CSMS to adjust charging behavior and minimize the impact on the grid during peak demand periods. This enables EV charging to participate in demand response programs, helping to balance the grid and prevent overloading.

Country-specific charging regulations

UK EVSCP regulations

The UK EVSCP (Electric Vehicle Smart Charging Protocol) Regulations require that all new public EV chargers are equipped with smart charging functionality. The regulations aim to reduce peak electricity demand by enabling charge points to adjust charging in response to grid conditions. Key requirements include default off-peak charging, randomized delays to prevent demand spikes, user override capabilities, and secure communication with data protection measures.

While OCPP is not mandated, it can support compliance by enabling communication between Charging Stations and a CSMS. Through OCPP Smart Charging, charging behavior can be adjusted dynamically based on grid signals, helping reduce grid strain and improve energy efficiency.

German calibration law – Eichrecht

To comply with the German Calibration law (Eichrecht) regulations, EV charging stations must meet specific criteria, including installing a kWh meter to ensure precise billing and accurate data reporting. OCPP can support compliance by enabling reliable communication between Charging Stations and a CSMS, including the transfer of metered data. This data can be processed and presented to the EV driver (e.g., via a mobile application), ensuring transparency and verifiability of billing information.

9. Getting started with OCPP

Implementing OCPP requires careful consideration of both software and hardware components, as well as long-term maintenance and upgrade strategies. Here’s an overview of the OCPP implementation process.

EV charging software

There are two primary approaches to implementing OCPP. You can either build your own implementation of the protocol, which requires an experienced development team to build the solution from scratch, or you can buy an existing solution. 

While building a custom implementation provides complete control and flexibility over the solution, it also comes with significant downsides. It is worth noting that even industry giants opt for existing solutions due to the steep learning curve in the EV charging industry, which requires a deep understanding of the complexity of various use cases, numerous protocols, and local market regulations.

Ready-made solutions support a wide range of business models and use cases, making it easier to find a solution that fits specific needs. These solutions typically include features such as tariff management, remote monitoring, and smart charging, enabling faster deployment and reduced operational complexity.

Implementing OCPP directly from the documentation generally provides basic functionality that lacks the requirements for comprehensive EV charging business operations. Instead, opting for an existing solution can save time, resources, and provide access to advanced features that are essential for success.

EV charging hardware

The quality of a Charging Station’s OCPP implementation has a direct impact on interoperability and system performance. Poor implementations can lead to limited functionality and unreliable communication with the CSMS.

Evaluating hardware compatibility and OCPP compliance is therefore essential. This typically involves testing core and advanced OCPP functionalities, such as remote transaction control, firmware updates, and smart charging.

Close collaboration between software providers and hardware manufacturers can help improve interoperability and ensure reliable operation across different Charging Station models.

Testing OCPP implementation

At AMPECO, we’ve developed a comprehensive evaluation procedure that covers both core and advanced scenarios. It involves extensive testing of all OCPP feature profiles and crucial functionalities, including remote start/stop of charging sessions, firmware updates, and smart charging capabilities, providing you with reliable, effective solutions for your EV charging needs.

These tests allow us to collaborate closely with hardware manufacturers by providing them with specific recommendations on how to improve their OCPP implementation. In doing so, we contribute to the industry and support all stakeholders’ growth. Our platform allows network operators to choose hardware that meets their specific needs, as we have compatibility across charging stations from 40+ manufacturers.

Maintenance and Upgrades

Maintaining and upgrading your OCPP version and implementation is essential as protocol versions are not backward compatible, meaning newer versions may not work with older implementations. Upgrading to a new version often requires a hardware or software upgrade, so it’s important to plan accordingly before making any changes to avoid compatibility issues. Regular system maintenance is also essential to ensure that the OCPP version you use remains efficient and effective over time and continues to meet the evolving needs of the charging infrastructure.

10. Latest developments in OCPP

The OCPP standard constantly evolves, with new developments and updates being released regularly.

One recent development is the OCPP Compliance Test Tool (OCTT2), which helps developers test protocol implementations against official specifications and ensure compliance with industry standards.

OCTT2 comprises the initial set of OCPP 2.0.1 test cases; however, future enhancements are expected to include additional test cases and coverage for functional blocks, such as ISO15118, and APIs that enable automated execution of test cases for integration into CI/CD and test automation. Charging station manufacturers and service providers can apply for certification of their products and services to demonstrate compliance with the OCPP standard.

The OCPP standard is constantly evolving to continue to improve functionality and accommodate new features. This progress is driven by working groups of industry experts collaborating to develop new standards and best practices for EV charging infrastructure. Plugfest events are also held regularly, bringing together developers and manufacturers to test their OCPP implementations for interoperability. 

How AMPECO helps you maximize the benefits of OCPP

For charge point operators seeking to scale and manage their EV charging infrastructure, understanding and utilizing OCPP offers multiple advantages.

By adopting OCPP, operators can enjoy improved communication between charging stations and back-end systems, greater interoperability, flexibility, and control over their systems. With the ongoing development of the protocol, OCPP continues to evolve and improve, supporting the needs of EV drivers and the industry.

However, for EV charging network operators serious about growing their business, relying on software or hardware with basic OCPP implementation is not enough. The key is how it is implemented and how all the complex use cases are addressed. This is where platforms like AMPECO come in – with years of development and driven by real-life practical use cases from clients in 70+ markets worldwide. Our platform brings not just the basic implementation of OCPP but also custom flows and interpretation of how business cases can be turned into technical solutions.

We encourage all EV charging network operators to adopt OCPP as part of their EV charging infrastructure and to consider working with an EV charging management platform like AMPECO to unlock even more value from this powerful protocol. With our expertise and experience in developing custom solutions for complex use cases, we can help you take your EV charging business to the next level.