ISO 15118: The Complete Guide to EV Charging Communication Standards (2026 Edition)

18 November, 2025

I. Introduction: Why ISO 15118 Matters in 2026

The global electric vehicle (EV) fleet is projected to reach approximately 40 million units by the end of 2025 (IEA, Announced Pledges Scenario), driving unprecedented demand for intelligent, interoperable, reliable, secure, and standardized charging infrastructure. At the heart of this evolution is ISO 15118, the international standard governing digital communication between electric vehicles and charging stations.

ISO 15118 is no longer optional. With regulatory frameworks such as the EU’s AFIR, the U.S. NEVI program, and pilot projects in China requiring compliance by 2025–2027, the standard has become a critical factor for EV manufacturers, charge point operators (CPOs), and energy companies aiming for global market access.

This guide provides a comprehensive, EEAT-compliant overview of ISO 15118, its technical capabilities, regulatory implications, and practical applications in the EV ecosystem.This guide provides a comprehensive, EEAT-compliant overview of ISO 15118, its technical capabilities, regulatory implications, and practical applications in the EV ecosystem. Sources include the International Energy Agency (IEA, 2025)for global EV adoption trends, the EU Alternative Fuels Infrastructure Regulation (AFIR, 2023),for regulatory requirements, the NEVI Program (U.S., 2024),for U.S. interoperability standards and CharIN interoperability tests (2024) for ISO 15118 certification and testing insights.

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II. What Is ISO 15118?

ISO 15118 (Road Vehicles – Vehicle to Grid Communication Interface) defines how electric vehicles communicate with charging stations. It covers digital authentication, energy transfer coordination, smart charging, and bidirectional power flow.

The standard is divided into multiple parts:

ISO 15118-2/3: Communication protocol specification for wired AC/DC charging
ISO 15118-20: Advanced features including V2G (Vehicle-to-Grid), automated connection devices, and wireless power transfer
Relationship with OCPP & IEC 61851: While OCPP manages backend charging station communication, ISO 15118 governs direct EV-to-charger interactions, ensuring interoperability and future-proofing

ISO 15118 enables a unified communication framework that transforms EVs into mobile energy assets, rather than just transportation devices.

III. Core Technical Capabilities of ISO 15118

1. Automated Authentication

Vehicles can authenticate directly with charging stations using embedded digital certificates, reducing manual user actions. This mechanism integrates seamlessly with:

Vehicle fleet management systems
Public charging authorization
Backend billing platforms

2. Plug & Charge via Certificate-Based Billing

Plug & Charge is the implementation of ISO 15118’s automated billing capability:

Establishes a TLS-secured communication channel between EV and charger
Performs authentication, authorization, and invoicing automatically
Works across multiple operators without manual credential input

This ensures that both OEMs and CPOs comply with security standards while simplifying the charging experience for end users.

3. Bidirectional Energy Flow (V2G)

ISO 15118-20 supports vehicle-to-grid (V2G), vehicle-to-home (V2H), and vehicle-to-building (V2B):

Enables EVs to discharge energy back to the grid during peak demand
Integrates with energy management systems for dynamic load balancing
Supports renewable energy integration and microgrid stabilization

Bidirectional communication is a core enabler for decentralized energy storage and smart grid applications.

4. Public Key Infrastructure (PKI) for Security

ISO 15118 mandates a certificate-based PKI framework:

Certificates issued by OEMs or certificate authorities
Supports certificate lifecycle management (issuance, revocation, renewal)
Ensures secure communication and protects against unauthorized access or billing fraud

PKI compliance is essential for enabling Plug & Charge and V2G operations.

IV. Impact on Charge Point Operators (CPOs)

ISO 15118 offers significant benefits for CPOs:

Operational efficiency: Automated authentication and billing reduce manual intervention
Interoperability: Compatible with multiple OEMs and charging networks
Compliance readiness: Meets AFIR and NEVI regulatory requirements for public charging
Enhanced user experience: Smooth, frictionless charging encourages EV adoption

For operators, ISO 15118 transforms stations into intelligent assets capable of supporting advanced services such as dynamic pricing and demand response.

V. Implications for EV Manufacturers and the Supply Chain

1. OEMs

Vehicles must integrate hardware security modules (HSMs) and certificate storage
15118-20 compliance enables Plug & Charge and V2G capabilities
Early adoption positions OEMs competitively in regulated markets

2. Charging Station Manufacturers

Mainboards must support Power Line Communication (PLC) and high-level communication protocols
Firmware updates and certificate management must be compatible with backend CSMS
Interoperability testing (e.g., CharIN Testival) ensures global deployment readiness

3. Energy Companies and Utilities

ISO 15118 enables EVs as distributed energy storage for grid balancing
Supports demand response programs, peak shaving, and frequency regulation
Facilitates integration of renewable generation and microgrids

VI. Regulatory Landscape and Global Standards

EU AFIR: EU AFIR: Mandatory ISO 15118 support for V2G-capable chargers is required from January 2026; full Plug & Charge compliance for newly deployed public charging points is mandated by 2027.
U.S. NEVI Program: Encourages ISO 15118-compatible chargers for interoperability
China: Dual-direction charging pilot programs in grid demonstration zones
Japan: CARICS initiatives aligned with ISO 15118-20 standards

Compliance with these regulations is crucial for global market access and future-proof charging infrastructure.

VII. How to Verify ISO 15118 Support

To ensure a charger is truly ISO 15118-compliant:

Verify TLS-secured communication and certificate management
Confirm vehicle and station interoperability with ISO 15118-20
Check for backend system integration supporting billing and energy management
Ensure V2G readiness if bidirectional energy flow is required
Conduct field tests with multiple OEM vehicles, not just rely on spec sheets

A compliance checklist improves reliability and reduces operational risk.

VIII. Industry Trends and Future Outlook

ISO 15118-20 will become the baseline for bidirectional charging in commercial and residential markets
EVs will increasingly act as mobile energy assets
Charging stations will evolve from hardware-centric to communication-centric assets
Utilities will integrate EV fleets for grid stabilization and energy market participation
Emerging AI-based energy management platforms may leverage 15118 data for predictive load balancing

These trends indicate that ISO 15118 is central to the future of intelligent energy networks.

IX. Frequently Asked Questions

Q1: Is ISO 15118 mandatory for all EVs?

A: Not all EVs are currently required to support ISO 15118. However, under the EU’s AFIR regulation, all newly deployed V2G-capable public charging points must support ISO 15118 starting from 2026. To use these advanced chargers with features like Plug & Charge or V2G, EVs must be compliant with ISO 15118.

Q2: Can all vehicles use Plug & Charge?

A: Only those with embedded certificates and compliant onboard HSMs.

Q3: Does V2G require extra hardware?

A: Yes. Both the EV and the charging station must support bidirectional energy flow. EVs need compatible battery management systems and HSMs, while chargers require bidirectional power electronics and ISO 15118-20 communication support.

Q4: Who manages the certificates?

A: It’s a shared ecosystem. Typically, OEMs (car manufacturers) issue contract certificates to their vehicles. These certificates are often rooted in a Trusted Root Certificate Authority managed by consortiums like CharIN. Charge Point Operators (CPOs) or their chosen Mobility Service Providers manage the backend validation of these certificates during charging sessions.

Q5: How does ISO 15118 relate to OCPP?

A: ISO 15118 governs secure EV-to-charger communication, including authentication and Plug & Charge. OCPP handles charger-to-backend communication for session management, billing, and monitoring. Together, they provide an end-to-end interoperable EV charging solution.

X. Conclusion

ISO 15118-Compliant and Future-ReadyISO 15118 has evolved from a technical protocol into a strategic enabler for the global EV ecosystem, and EVB charging stations are fully aligned with this vision.

For OEMs: EVB chargers support seamless Plug & Charge and V2G functionality, allowing vehicles to authenticate automatically and participate in bidirectional energy flows.
For Charge Point Operators (CPOs): EVB solutions reduce operational costs, improve interoperability, and enable participation in smart grid programs.
For Energy Companies and Utilities: EVB chargers integrate EVs into grid management and renewable energy optimization, facilitating peak shaving and energy storage.
For EV Drivers: Provides a frictionless, secure, and user-friendly charging experience, with no apps or RFID cards required.

With global policies such as AFIR, NEVI, and evolving GB/T standards enforcing ISO 15118 compliance, adopting EVB chargers early is not just advantageous—it is a strategic move for 2026 competitiveness in the EV market.

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Seamless Plug & Charge Experience
EVB charging stations fully support ISO 15118 Plug & Charge, enabling drivers to authenticate and start charging automatically using vehicle certificates. No apps, RFID cards, or manual input are needed. This enhances user convenience and aligns with global EV adoption trends.

Bidirectional Charging and V2G Ready
EVB harger supporting Vehicle-to-Grid (V2G), energy flows according to ISO 15118-20 standards. Utilities and building operators can leverage EVB chargers for peak shaving, grid balancing, and renewable energy integration, making EVB a strategic partner for smart energy anagement.

Advanced Security with PKI
EVB implements the Public Key Infrastructure (PKI) framework required by ISO 15118, ensuring secure authentication, encrypted communication, and certificate lifecycle management. This protects both users and operators from cyber threats, while meeting global regulatory compliance.

Future-Proof and Interoperable
• OEM Compatibility: EVB chargers have passed interoperability testing with major EV brands, ensuring Plug & Charge and V2G functions work seamlessly.
• Scalable: Firmware can be updated remotely to support evolving ISO 15118 standards and local regulatory requirements.
• Sustainability: By enabling intelligent energy flows, EVB chargers contribute to decarbonization goals for fleets, businesses, and cities.