ISO 15118 — formally titled Road Vehicles — Vehicle to Grid Communication Interface — is the international standard published by the International Organization for Standardization (ISO) that defines the digital communication protocol between an electric vehicle (EV) and an Electric Vehicle Supply Equipment (EVSE). It is the technical backbone of smart EV charging: without ISO 15118, the charger and vehicle can only exchange basic power delivery signals; with it, they can negotiate charging schedules, authenticate automatically, manage billing, respond to grid pricing, and enable bidirectional energy flow.
ISO 15118 is not a single document but a multi-part standard series, each part defining a specific layer of the communication stack — from use-case definitions and physical-layer signaling through application-layer messages and security requirements. Understanding which part does what, and how the full stack interacts with complementary protocols like OCPP and OCPI, is essential for CPOs, OEM engineers, and infrastructure planners specifying hardware for 2026 and beyond.
Joint Tech holds ISO 15118 certification via Hubject, with DC fast chargers supporting ISO 15118 Plug & Charge communication. See also: What Does ISO 15118 Mean? and ISO 15118 and ISO 14443 Explained.
Related glossary entries: Plug & Charge (PnC) | OCPP | V2G | DC Fast Charging (DCFC) | AFIR
Table of Contents
- What Is ISO 15118?
- Why ISO 15118 Exists: The Limits of Basic Signaling
- The ISO 15118 Standard Series: Every Part Explained
- The Protocol Stack: How the Layers Work Together
- Physical Layer: HomePlug GreenPHY PLC and 10BASE-T1S Ethernet
- Use Cases: What ISO 15118 Enables
- ISO 15118 vs. DIN SPEC 70121: What Is Still Deployed
- ISO 15118 vs. OCPP: Different Layers, Complementary Roles
- ISO 15118-2 vs. ISO 15118-20: Key Differences
- Hardware Requirements: What CPOs and OEMs Must Implement
- Regulatory Requirements: AFIR and NEVI Mandates
- Adoption Status and Remaining Challenges
- A–Z Quick-Reference Glossary
- FAQ
1. What Is ISO 15118?
ISO 15118 defines the communication interface between the Electric Vehicle Communication Controller (EVCC) in the vehicle and the Supply Equipment Communication Controller (SECC) in the charging station — the two software/hardware modules that manage all data exchange during a charging session.
This interface operates over the charging cable itself, using either Power Line Communication (PLC) or Ethernet — depending on the protocol version — and covers everything that happens from the moment the cable is plugged in to the moment it is removed:
- Protocol negotiation (which ISO 15118 version to use)
- Security handshake (TLS certificate exchange)
- Authentication and authorization (Plug & Charge or external ID)
- Charging parameter negotiation (voltage, current, power limits, state of charge)
- Smart charging schedule negotiation (grid-responsive, price-responsive)
- Metering and session data exchange
- Bidirectional power flow control (V2G, V2H, V2B — in ISO 15118-20)
- Session termination and billing record generation
The standard scope explicitly covers the link between EVCC and SECC only. Communication from the SECC onward — to the backend Charge Point Management System (CPMS), to the grid operator, or to billing systems — is handled by OCPP and OCPI, not ISO 15118.
ISO 15118 is part of the Combined Charging System (CCS) standard family and applies to both AC and DC charging — though practical implementation is more complex for AC due to the AC-charging communication architecture.
2. Why ISO 15118 Exists: The Limits of Basic Signaling
Before ISO 15118, EV charging communication used only basic analog signaling defined in IEC 61851-1 — a simple PWM (pulse-width modulation) signal on the control pilot (CP) wire of the charging cable. This signal communicates one piece of information: the maximum current the EVSE can supply. The vehicle uses this to set its charge rate accordingly.
Basic signaling cannot support:
- Driver authentication or billing — no identity data can be transmitted
- Smart charging schedules — the vehicle cannot tell the EVSE when it needs to be charged, or at what rate
- Grid-responsive demand response — no pricing or frequency signals can be relayed to the vehicle
- Bidirectional energy flow — the analog signal has no concept of export direction
- Security — no encryption, no certificate verification, no protection against tampering
ISO 15118 replaces this analog channel with a full IP-based digital communication stack running over the same physical cable — transforming the EVSE from a “dumb power socket with a cable” into a digitally intelligent interface capable of secure, bidirectional, grid-aware energy management. As smart charging functions become central to both CPO business models and grid stability, ISO 15118 is the enabling layer that makes them possible at scale.
3. The ISO 15118 Standard Series
ISO 15118 is published in numbered parts, each defining a specific layer or aspect of the communication system. Not all parts are relevant to every deployment — understanding which parts apply to your use case (DC fast charging vs. AC, first-generation vs. second-generation, wired vs. wireless) determines your hardware and software requirements.
| Part | Title | Published | What It Defines | Relevance |
|---|---|---|---|---|
| ISO 15118-1 | General information and use-case definition | 2013 (Ed.2: 2019) | Terms, definitions, general requirements, and use cases that form the basis for all other parts. Defines the EVCC/SECC concept and scopes the overall system boundary. | Foundation document — not directly implemented but defines the framework |
| ISO 15118-2 | Network and application layer requirements (1st generation) | 2014 (Ed.2: 2022) | The primary application-layer standard for first-generation ISO 15118. Defines all messages between EVCC and SECC: Plug & Charge, smart charging, EIM, power delivery negotiation. Uses PLC (HomePlug GreenPHY) as physical layer. Optional TLS (one-way). | Current deployment baseline. Mandated for new public AC chargers in EU from January 2026 (AFIR). |
| ISO 15118-3 | Physical and data link layer requirements (1st generation) | 2015 | Defines the physical layer for ISO 15118-2: HomePlug GreenPHY (HPGP) PLC over the control pilot wire. Specifies signal attenuation characterization (SLAC) for link setup. Confirmed current in 2024. | Required for all ISO 15118-2 deployments. Hardware: PLC modem chip in both EVSE and vehicle. |
| ISO 15118-4 | Network and application layer conformance tests (1st gen) | 2018 | Conformance test specifications for ISO 15118-2 implementations — used by testing labs and OEMs to validate protocol compliance. | Certification and testing |
| ISO 15118-5 | Physical and data link layer conformance tests (1st gen) | 2018 | Conformance tests for ISO 15118-3 physical layer implementations. | Certification and testing |
| ISO 15118-8 | Physical and data link layer requirements — wireless | 2020 | Defines wireless communication requirements for inductive (wireless) charging — the physical/data link layer alternative to the wired PLC in ISO 15118-3. For wireless power transfer (WPT) applications. | Wireless charging infrastructure (emerging) |
| ISO 15118-20 | 2nd generation network and application layer requirements | 2022 (MCS Annex K: 2024) | Second-generation standard superseding ISO 15118-2 for new deployments. Adds: mandatory mutual TLS 1.3, V2G / V2H / V2B bidirectional power flow, wireless power transfer (WPT), automated connection devices (ACD), multiple simultaneous contracts, cryptographic agility. Uses either HPGP PLC or 10BASE-T1S Ethernet as physical layer. Required for MCS communication (Annex K). | Next-generation baseline. Required for V2G-capable public stations in EU from January 2027 (AFIR). Required for MCS communication. |
| ISO 15118-21 | 2nd generation — common conformance tests | 2023 | Conformance test framework for ISO 15118-20 implementations. | Certification and testing for ISO 15118-20 |
| ISO 15118-23 | 2nd generation — DC-specific conformance tests | In development | DC-specific conformance tests for ISO 15118-20. | DC fast charger certification |
Parts 6, 7, 9, and 10 were either withdrawn or are reserved for future use. For most CPOs and OEMs, the immediately relevant parts are ISO 15118-2 + ISO 15118-3 (current generation) and ISO 15118-20 (next generation, now entering regulatory mandate territory).
4. The Protocol Stack: How the Layers Work Together
ISO 15118 follows a layered architecture modeled on the OSI network model. Each layer has a defined role, and the protocol stack is designed so that the upper layers (application, security) are independent of the physical-layer technology — which is why ISO 15118-20 can operate over either PLC or Ethernet without changing the application messages.
| Layer | Function | ISO 15118-2 Technology | ISO 15118-20 Technology |
|---|---|---|---|
| Physical / Data Link | Raw signal transmission over the charging cable | HomePlug GreenPHY (HPGP) PLC over Control Pilot wire — ISO 15118-3 | HPGP PLC or 10BASE-T1S Single Pair Ethernet (mandatory for MCS) |
| Network / Transport | IP addressing and packet routing between EVCC and SECC | IPv6 / TCP | IPv6 / TCP |
| Security | Encrypted channel + mutual identity verification | TLS 1.2 (optional for EIM; mandatory for PnC, one-way) | TLS 1.3 (mandatory, mutual — both sides authenticate) |
| Application | EV-EVSE message exchange: auth, power negotiation, smart charging, billing | ISO 15118-2 message set (XML/EXI encoded) | ISO 15118-20 message set (extended use cases, V2G, multi-contract) |
The session begins at the physical layer when the cable is connected. IEC 61851 basic signaling activates first, then the PLC or Ethernet link is established. Once the digital link is up, the EVCC and SECC negotiate which ISO 15118 version to use — and from that point all communication runs through the layered stack above.
5. Physical Layer: HomePlug GreenPHY PLC and 10BASE-T1S Ethernet
HomePlug GreenPHY (HPGP) — ISO 15118-2 and ISO 15118-20 (wired DC/AC)
HomePlug GreenPHY (HPGP) is the power line communication standard used as the physical and data link layer for ISO 15118-2 (and optionally ISO 15118-20). It transmits data at up to 10 Mbit/s by modulating a signal onto the existing control pilot (CP) wire of the CCS charging cable — the same wire used for basic IEC 61851 PWM signaling.
Key characteristics of HPGP in EV charging:
- Uses OFDM (Orthogonal Frequency-Division Multiplexing) in the 2–28 MHz band across ~917 subcarriers
- SLAC (Signal Level Attenuation Characterization) protocol for matching the correct EVSE to the vehicle when multiple chargers are nearby — preventing cross-talk in multi-charger installations
- Enables IP networking over the charging cable without additional dedicated communication wires
- Hardware requirement: a HPGP modem chip in both the EVSE (SECC) and the vehicle (EVCC) — this is why ISO 15118-2 compatibility cannot be added to older hardware by firmware update alone
10BASE-T1S Single Pair Ethernet — ISO 15118-20 (MCS)
For Megawatt Charging System (MCS) applications, ISO 15118-20 uses 10BASE-T1S — an IEEE automotive Ethernet standard running at 10 Mbit/s over a single twisted pair — rather than HPGP PLC. The switch is driven by EMI immunity: at the current levels involved in MCS (up to 3,000 A DC), the electromagnetic noise environment is too severe for PLC to reliably meet the <60 ms latency requirement validated by CharIN. Ethernet’s differential signaling is inherently more immune to common-mode EMI from the traction circuit.
For standard CCS2 DC and AC charging using ISO 15118-20, HPGP PLC remains the physical layer — 10BASE-T1S is specifically mandated for MCS applications under IEC TS 63379 and Annex K of ISO 15118-20.
6. Use Cases: What ISO 15118 Enables
ISO 15118 defines a set of use cases that the standard is designed to support. Each use case represents a specific functionality that requires digital vehicle-to-EVSE communication beyond what basic IEC 61851 signaling can provide.
Authentication: EIM and Plug & Charge
ISO 15118 defines two authentication modes:
- External Identification Means (EIM): The driver authenticates using an external method — RFID card, QR code, contactless payment, or app — before the session starts. ISO 15118 still manages the power delivery and smart charging session, but identity is established externally rather than via the cable.
- Plug & Charge (PnC): Authentication is handled automatically via digital certificate exchange over the cable. No driver interaction required. See Plug & Charge (PnC) Glossary for the full technical breakdown.
Smart Charging and Charging Schedule Negotiation
One of ISO 15118’s most commercially significant use cases — and entirely distinct from PnC — is smart charging schedule negotiation. The vehicle can communicate to the EVSE:
- Its current state of charge (SoC) and battery capacity
- The departure time by which it needs to be fully charged
- Its preferred charging profile (as fast as possible, or spread over available time)
The EVSE can respond with:
- A proposed charging schedule based on grid pricing signals, renewable energy availability, and local load constraints
- Power setpoint updates in real time as conditions change
- Grid frequency or voltage response requests (demand response)
This negotiation is the technical foundation for dynamic load balancing at multi-charger sites and for grid-level demand response programs that compensate fleet operators or CPOs for grid flexibility services. See also: smart functions of EV chargers.
Vehicle-to-Grid and Bidirectional Energy Services (ISO 15118-20)
ISO 15118-20 extends the communication framework to cover bidirectional power flow — where the vehicle battery discharges energy back into the grid, building, or home. This requires the communication layer to manage not just charging setpoints but also discharging setpoints, grid export limits, and energy pricing for exported power. The specific bidirectional modes defined are:
- V2G (Vehicle-to-Grid): EV discharges to the public utility grid via the EVSE
- V2H (Vehicle-to-Home): EV powers household loads directly
- V2B (Vehicle-to-Building): EV supplies a commercial building’s loads
For a comprehensive breakdown of bidirectional energy flows, see the V2G Glossary and V2G Smart Charging Technology.
Wireless Charging (ISO 15118-8 / ISO 15118-20)
ISO 15118-8 and the wireless provisions of ISO 15118-20 define the communication interface for inductive (wireless) power transfer — where the vehicle parks over a ground-mounted charging pad and charges without a physical cable. The communication stack is identical in structure to wired charging; only the physical layer changes (wireless RF rather than PLC). Commercial wireless charging using ISO 15118 is currently limited to specialized fleet depot and premium passenger car applications.
Automated Connection Devices (ISO 15118-20)
ISO 15118-20 includes provisions for Automated Connection Devices (ACD) — robotic or automated systems that physically connect the charging cable to the vehicle without driver action. The communication protocol supports the handshake required between the ACD, EVSE, and vehicle. Relevant for autonomous vehicle charging, warehouse logistics, and round-the-clock fleet depot operations.
7. ISO 15118 vs. DIN SPEC 70121: What Is Still Deployed
DIN SPEC 70121 — published by the German standards institute in 2012 — was the first standardized DC charging communication protocol. It was developed as a transitional solution before ISO 15118-2 was finalized, using the same HPGP PLC physical layer but with a simplified application layer that supports only DC charging and has no security, no Plug & Charge, and no smart charging negotiation.
| Feature | DIN SPEC 70121 | ISO 15118-2 | ISO 15118-20 |
|---|---|---|---|
| Published | 2012 | 2014 | 2022 |
| Charging type | DC only | AC + DC | AC + DC + wireless |
| Physical layer | HPGP PLC | HPGP PLC (ISO 15118-3) | HPGP PLC or 10BASE-T1S |
| TLS security | None | Optional (mandatory for PnC) | Mandatory mutual TLS 1.3 |
| Plug & Charge | No | Yes | Yes (enhanced) |
| Smart charging | No | Yes | Yes (extended) |
| V2G / bidirectional | No | No | Yes |
| V2G SoC reporting | Yes (basic) | Yes | Yes |
| AFIR compliance (EU) | No | Yes (from Jan 2026) | Yes (from Jan 2027) |
| Deployment share (2025) | Dominant in installed base | Growing | Early stage |
Despite ISO 15118-2’s 2014 publication, DIN SPEC 70121 remains dominant in the installed DC fast charger base as of 2025–2026 — primarily due to first-mover advantage and the slow pace of OEM ISO 15118-2 rollout on the vehicle side. In practice, when a vehicle and charger both support both standards, they negotiate the highest common protocol — but many sessions still fall back to DIN SPEC 70121 if PnC certificates are not properly provisioned end-to-end.
Joint Tech’s EVD003 DC fast charger supports both DIN SPEC 70121 and ISO 15118, ensuring backward compatibility with the installed vehicle fleet while being ready for full PnC deployments.
8. ISO 15118 vs. OCPP: Different Layers, Complementary Roles
The most common source of confusion in EV charging protocols is the relationship between ISO 15118 and OCPP. They are often mentioned together but they govern entirely different communication links — and both are needed for a fully featured charging deployment.
| Dimension | ISO 15118 | OCPP |
|---|---|---|
| Communication link | Vehicle (EVCC) ↔ Charging station (SECC) | Charging station ↔ Backend CSMS |
| Physical medium | Charging cable (PLC or Ethernet) | Internet (cellular, Wi-Fi, Ethernet) |
| Primary function | Authentication, power negotiation, smart charging at vehicle level | Remote management, billing, firmware updates, network monitoring |
| Who publishes | ISO (International Organization for Standardization) | Open Charge Alliance (OCA) |
| Key versions | ISO 15118-2 (2014), ISO 15118-20 (2022) | OCPP 1.6, OCPP 2.0.1, OCPP 2.1 |
| Relationship | Complementary. ISO 15118 handles EV↔charger; OCPP carries the session data upward to the CPO backend. OCPP 2.0.1 is required for full ISO 15118 PnC integration — it carries the certificate management messages between charger and CSMS. | |
The practical implication: a charger can support OCPP without supporting ISO 15118 (most installed base chargers), but a charger cannot deliver full Plug & Charge without both ISO 15118 and OCPP 2.0.1. The OCPP 2.0.1 “ISO 15118 functional block” carries the certificate installation and verification messages between the charger and the CSMS — without it, the PKI backend cannot provision or validate PnC certificates. See also: What Is OCPP in EV Chargers?
OCPP 2.1 further extends this integration by adding ISO 15118-20 V2G support — enabling the CSMS to manage discharging schedules, grid service contracts, and bidirectional energy flow records from the backend.
9. ISO 15118-2 vs. ISO 15118-20: Key Differences for Procurement
When specifying new EVSE hardware, understanding the practical differences between the two active generations of ISO 15118 determines which hardware generation to procure and what backend integration is required.
| Feature | ISO 15118-2 | ISO 15118-20 |
|---|---|---|
| Published | 2014 (Ed.2: 2022) | 2022 |
| TLS version | TLS 1.2 (optional for EIM; mandatory for PnC) | TLS 1.3 (mandatory, mutual authentication) |
| Certificate size support | Standard X.509 | Larger certificates up to 1,600 bytes — requires more capable hardware |
| Contract support | Single contract per session | Multiple simultaneous contracts — driver can choose at session start |
| Bidirectional (V2G) | No | Yes — V2G, V2H, V2B |
| Wireless charging | No | Yes (ACD, WPT) |
| MCS communication | No | Yes (Annex K) |
| Cryptographic agility | Fixed algorithm set | Algorithm-agile — can adopt new cryptographic standards as they emerge |
| Physical layer | HPGP PLC only | HPGP PLC or 10BASE-T1S Ethernet |
| AFIR EU mandate | All new public AC chargers from January 2026 | All new V2G-capable public stations from January 2027 |
| Hardware upgrade path | Cannot be retrofitted — requires PLC-capable SECC hardware from design stage | Requires upgraded SECC with TLS 1.3 support and larger certificate storage |
Key procurement insight: ISO 15118-20 is not simply a firmware upgrade from ISO 15118-2. The larger certificate sizes, TLS 1.3 requirement, and V2G message handling require more capable processor and memory resources in the SECC hardware. CPOs buying EVSE hardware today for deployments expected to serve V2G use cases by 2027 should specify ISO 15118-20-ready hardware explicitly — not assume upgrade path availability.
10. Hardware Requirements: What CPOs and OEMs Must Implement
EVSE (Charging Station) Hardware Requirements
- SECC module: The Supply Equipment Communication Controller — integrates PLC modem (HPGP for ISO 15118-2/-20 wired, or 10BASE-T1S interface for MCS), processor for TLS and ISO 15118 application stack, and network interface to CSMS
- PLC modem chip (HomePlug GreenPHY): Required for ISO 15118-2 and ISO 15118-20 wired deployments. Cannot be added retrospectively to hardware without this chip.
- Secure element / HSM: For storing EVSE certificates and performing TLS cryptographic operations. Required for PnC deployments.
- TLS stack: TLS 1.2 for ISO 15118-2; TLS 1.3 for ISO 15118-20
- OCPP 2.0.1 connectivity: Required for CSMS to provision and manage ISO 15118 certificates and receive PnC session authorization. Chargers with only OCPP 1.6 have limited PnC integration capability.
Vehicle (OEM) Hardware Requirements
- EVCC module: Electric Vehicle Communication Controller with HPGP PLC modem
- Hardware Security Module (HSM): Tamper-resistant secure element for contract certificate and private key storage
- V2G Root CA certificate: Pre-installed at factory by OEM — the trust anchor for all PnC sessions
- OTA update capability: Required for contract certificate renewal and EVCC firmware updates
- Sufficient memory and processor: ISO 15118-20 certificate sizes (up to 1,600 bytes) and TLS 1.3 require more capable hardware than ISO 15118-2
11. Regulatory Requirements: AFIR and NEVI Mandates
European Union — AFIR Implementing Acts
Under AFIR‘s implementing framework, ISO 15118 has been made mandatory for new publicly accessible charging infrastructure in two stages:
- 8 January 2026: All newly installed or substantially renovated publicly accessible AC Mode 3 charging points must implement EN ISO 15118-2:2016 — meaning digital PLC communication must replace or supplement the basic PWM signaling. This covers every public AC wallbox and post installed from this date.
- 1 January 2027: All newly installed or renovated publicly accessible and private Mode 3 (AC) charging points — and all new V2G-capable stations — must implement EN ISO 15118-20:2022. This prepares the entire new-installation base for bidirectional energy services.
These deadlines mean that EVSE hardware commissioned for European public use from 2026 must include HPGP PLC-capable SECC hardware from day one. Firmware promises of future ISO 15118 support are not sufficient — the hardware must support it at installation.
United States — NEVI Program
The National Electric Vehicle Infrastructure (NEVI) program requires all NEVI-funded stations to support OCPP 2.0.1 and ISO 15118 communication. While NEVI does not mandate Plug & Charge activation from day one, the hardware and protocol requirements ensure all NEVI-funded infrastructure is PnC-capable as the ecosystem matures. Network reliability requirements (97%+ uptime) and interoperability requirements under NEVI also drive ISO 15118 adoption as the standard baseline for smart charging communication.
12. Adoption Status and Remaining Challenges (2026)
Where ISO 15118 Is Deployed
- DC fast charging networks: Major European and North American DC fast charging networks — including Ionity (Europe) and Electrify America (US) — support Plug & Charge via ISO 15118-2. These are the most advanced deployments operationally.
- AC charging: Hardware support is increasingly common in new AC wallboxes and posts; software ecosystem for full AC PnC is still maturing. AFIR’s January 2026 mandate is driving rapid hardware refresh.
- Vehicles: More than twenty OEM brands have announced ISO 15118 support. Volkswagen Group (Porsche, Audi, VW), BMW, Mercedes-Benz, Hyundai, and others have deployed PnC in production vehicles. Full interoperability across all OEM/eMSP/CPO combinations is still inconsistent.
Remaining Challenges
- DIN SPEC 70121 dominance: The installed base of DC chargers still largely operates on DIN SPEC 70121. Protocol negotiation means PnC works only when both vehicle and charger support ISO 15118-2 and the PKI is properly provisioned end-to-end — any gap in the chain causes fallback to DIN SPEC 70121 or EIM.
- TLS overhead: A TLS handshake adds approximately 1.5–2 seconds to session startup. Imperceptible in most use cases, but relevant for high-throughput DC fast charging sites and some fleet operations.
- PKI complexity: Certificate lifecycle management (issuance, renewal, revocation) across OEMs, eMSPs, CPOs, and eRoaming hubs remains operationally complex. Non-uniform provisioning processes vary by vehicle model and eMSP combination.
- AC Plug & Charge: ISO 15118-2 applies to both AC and DC charging, but AC PnC software is less mature in the deployed ecosystem. The January 2026 AFIR mandate for AC chargers is expected to accelerate software ecosystem development.
- ISO 15118-20 hardware migration: As the 2027 AFIR deadline approaches, CPOs face a hardware refresh requirement — ISO 15118-20’s TLS 1.3 and larger certificate sizes cannot be met by all existing ISO 15118-2 hardware. The next generation of high-power charging hardware is being designed with ISO 15118-20 from the ground up.
13. Frequently Asked Questions About ISO 15118
What does ISO 15118 actually do — and what doesn’t it cover?
ISO 15118 defines the digital communication protocol between the vehicle (EVCC) and the charging station (SECC) — everything that happens from cable plug-in to session termination, including protocol negotiation, TLS security handshake, authentication (Plug & Charge or EIM), power and charging schedule negotiation, and V2G messages (ISO 15118-20). It does not cover communication from the charging station to backend systems (that is OCPP), communication between backend systems (that is OCPI), vehicle-internal communication (battery BMS to EVCC), or the physical power delivery hardware.
What is the difference between ISO 15118 and OCPP?
ISO 15118 governs the EV-to-charger communication link — the protocol running over the charging cable between vehicle and station. OCPP governs the charger-to-backend communication link — between the charging station and the CPO’s Charge Point Management System (CSMS) over the internet. Both are needed for a fully featured smart charging deployment. OCPP 2.0.1 is specifically required to carry the certificate management messages that make ISO 15118 Plug & Charge work end-to-end.
Is ISO 15118 required by law in Europe?
Yes, under AFIR’s implementing acts. From January 8, 2026, all newly installed or substantially renovated publicly accessible AC Mode 3 charging points in the EU must implement ISO 15118-2. From January 1, 2027, all new V2G-capable stations and new private and public Mode 3 AC chargers must implement ISO 15118-20. This means any AC charger commissioned for European public use from 2026 must include ISO 15118-2-capable hardware at installation — not as a future firmware promise.
Can ISO 15118 be added to an existing charger by firmware update?
No, in most cases. ISO 15118-2 requires a HomePlug GreenPHY (HPGP) PLC modem chip in the EVSE hardware. Charging stations without this chip cannot implement ISO 15118 regardless of firmware. Additionally, ISO 15118-20 requires TLS 1.3 support and larger certificate storage — which some ISO 15118-2-capable hardware may not support. The safest approach is to specify ISO 15118-20-ready hardware at procurement, with hardware-level SECC capability rather than relying on software upgrade paths.
What is the difference between ISO 15118-2 and ISO 15118-20?
ISO 15118-2 (2014) is the first-generation standard: AC and DC charging, optional TLS, single contract, no V2G. ISO 15118-20 (2022) is the second generation: mandatory mutual TLS 1.3, V2G/V2H/V2B bidirectional power flow, multiple simultaneous contracts, wireless charging, automated connection device support, cryptographic agility, and MCS communication (Annex K). ISO 15118-20 is not a firmware upgrade from -2 — it requires more capable SECC hardware with TLS 1.3 support and larger certificate storage capacity.
Specifying ISO 15118-capable EV charging hardware for European or North American deployments? Joint Tech holds ISO 15118 certification via Hubject. Our CE-certified DC fast chargers support Plug & Charge via ISO 15118 and DIN SPEC 70121, with OCPP 2.0.1 backend integration. For Type 2 AC chargers for European markets and CCS1/NACS chargers for North America, contact our team for AFIR and NEVI compliance specifications. For fleet depot projects needing both hardware and energy management, see our fleet and logistics charging solutions.
