What Is OCPP? A Practical Guide for Charging Operators

Use this article if you:

• are buying charging stations and keep seeing OCPP in the datasheet
• already have stations running and want to know what it would take to move them
• have stations from more than one manufacturer and are tired of a separate portal for each

OCPP is the open communication protocol between charging stations and charging management systems. The Open Charge Alliance publishes it and the specification can be downloaded from their site. Three versions are available: 1.6 from 2015, 2.0.1 from 2020, and 2.1 from 2025. A station that speaks OCPP can be connected to any management system that speaks it.

The stations you buy this year are not tied for their whole life to the software the manufacturer bundled with them. That is where the money is. If you want to try it on your own hardware, a 30-day free trial of ELVO takes one station and one address change.

An installer we work with took over three sites from the company that built them, and inherited three portals, three logins and no single answer to how much energy went out last month. Nothing was wrong with the stations. They were speaking a standard protocol to three different places at once. Bringing them under one platform did not involve a screwdriver.

How OCPP works

OCPP stands for Open Charge Point Protocol. It defines the messages a charging station and a management system send each other. The station announces itself when it boots, asks whether a card may charge, reports a session starting and stopping, sends meter readings, and reports status changes. The platform starts and stops sessions, resets the station, unlocks a connector, changes a setting, sets a charging profile that limits current, and pushes firmware.

Version	Released	What it brought	Where you meet it
OCPP 1.6	2015	Smart charging so a group of stations can share one supply, a card list held on the station itself, and more detailed status reporting	Still widely used, and what you meet on stations already installed
OCPP 2.0.1	2020	Managing the station’s own settings from the platform, reworked session handling, stronger security, more smart charging, support for ISO 15118 (plug and charge), and messages on the station’s screen	Newer hardware, tenders that ask for it
OCPP 2.1	2025	Power flowing both ways so a car can feed the building, control of on-site solar and batteries, more payment options, and battery swapping	Datasheets of models coming to market

One detail from that table changes what you buy. OCPP 1.6 and OCPP 2.0.1 are not compatible. A station and a platform have to match on the exact version, not just on the name OCPP.

Open means anyone can download the specification and implement it. Nobody needs a licence from the manufacturer of your stations to talk to them, and that includes the platform you pick next year.

What the protocol gives you once the stations are in service

1. You can change platform without changing stations. A station reports to whatever platform address you give it. Change that address and it reconnects somewhere else, keeps its serial number, its connectors and its meter, and comes back with its status. Every model is different: some let you change that address from a platform, some only at the station.
2. You can put different brands on one platform. The messages are the same whoever built the station. So four manufacturers on five sites arrive as one list of stations, sending the same records, and one export at the end of the month covers all of them.
3. You can encrypt the connection between station and platform. The secure version is a WebSocket connection over TLS, written as wss, and it is tested separately in the certification program. Ask the station vendor whether the firmware on your model does it, before you order rather than after.

What an OCPP certificate covers, and what it does not

Certification exists for two of the three versions. An independent laboratory, not the vendor, runs the product against the specification and issues a certificate that names exactly what passed. There is no certification program for OCPP 2.1, so “2.1 certified” on a datasheet describes something that does not exist yet, and “2.1 ready” is a statement of intent. Read a certificate for four things.

1. Which side it is for. A certificate is issued for a charging station, for a management system, or for the software stack inside a station. They are separate tests.
2. What it names. The vendor declares which parts of the protocol the product implements, and the laboratory tests those parts. Core is mandatory for everyone. On OCPP 1.6 everything around it is named separately and can be left out: firmware management, the local authorisation list held on the station, smart charging, remote trigger, reservations, and the security extension. The blocks are not the same on OCPP 2.0.1. There the named ones are Core, advanced security, smart charging and ISO 15118. Device management, reservations, the local list and on-screen tariff and messages sit as optional features inside Core. Inside each part the certificate records which optional features were tested and which were not. For a management system, a certificate on OCPP 1.6 covers the whole specification. On OCPP 2.0.1 it can name selected parts, with only Core mandatory. Since March 2025 it also has to carry security testing. So two products both called certified on the same version can have been tested for very different things.
3. Whether it is real. Every certificate sits in a public register on the Open Charge Alliance site, with the company, the product, the number and the date of registration. We read that register on 24 August 2026: 1,434 entries, nine in ten station certificates on 1.6, about one platform certificate in six on 2.0.1, and none at all on 2.1. Looking one up takes a minute. The register is also lopsided by geography. The EU-27 holds 34 of the 1,140 station certificates and 20 of the 294 platform ones. Most of the rest come from a handful of Asian manufacturing markets.
4. What it does not cover. The certificate says so itself: it is not a guarantee of the quality of the product. It is a conformance test of one product against the specification, nothing more. The two sides are tested separately, so a certified station and a certified platform can still need work to run together. The specification leaves plenty to the firmware, which is why two certified stations of different brands can behave differently. And it covers only the version and the parts printed on it.

A Core-only certificate covers booting, authorisation, configuration, transactions and remote control, and stops there. Twenty-five of the 178 certificates on OCPP 2.0.1 are exactly that. A full one adds advanced security, smart charging and ISO 15118, and six certificates go that far. If you need to cap the current across a site, only the second kind was tested for it.

The testing is done by an accredited laboratory, not by the vendor. The published test case document for OCPP 1.6 lists 112 cases, 45 for a management system and 67 for a charging station. On OCPP 2.0.1 the run is longer, because the protocol has more functional blocks. The optional features are tested too, if the vendor says the product supports them. The certificate then records which optional variables are implemented and what the read-only ones contain.

Plenty of vendors skip all that and print “OCPP compliant” on the datasheet anyway. The alliance keeps a public list of companies caught misusing its certification mark, with 19 names on it today.

So on the day of the integration you start from a tested baseline, and the parts named on the certificate tell you whether what you need was tested or only claimed. On the day of the sale, a buyer checks the register in a minute instead of taking your word. And a tender that asks for a certified platform rules out everyone without one.

ELVO holds an Open Charge Alliance certificate, Full and Security, registered as OCA.0016.1071.CSMS in June 2025. The certificate itself is a public document you can open now. The parts it names are Core, firmware management, the local authorisation list, smart charging, remote trigger and reservations, plus the security extension.

Where European rules touch OCPP

Two European rules describe what OCPP does without naming it, or any other protocol. That is why it keeps appearing in tender documents.

A tender that asks for a standardised protocol also has a standard to name: OCPP 2.0.1 ed3 was approved as an international standard, IEC 63584, in 2024.

The alternative fuels regulation, Regulation (EU) 2023/1804, applies directly in every member state and covers publicly accessible recharging points. Since 14 October 2024 those points have to be digitally connected: sending and receiving information in real time, monitored and controlled remotely, with sessions started and stopped and energy measured. Points built after 13 April 2024, or renovated after 14 October 2024, also have to be capable of smart recharging. That means the current going to the battery is adjusted in real time, from information received electronically.

A lot of people get “publicly accessible” wrong. It covers any site open to the general public, whether the property is public or private, so a supermarket car park counts and a staff-only office car park does not.

The buildings directive, Directive (EU) 2024/1275, has member states require non-proprietary and non-discriminatory protocols on the points it covers, which is the other way an open protocol ends up in a specification. What it asks of a building covers that one in full.

What OCPP does once your stations are on ELVO

If your stations are already installed and reporting to the manufacturer’s own platform, you do two things. First you add the stations in ELVO. Define the model once in the station catalogue, with manufacturer, model and connector types. Then add each station against it, with its name, its client, its location and its identifier. If you have a lot of them at once, you import them from a spreadsheet instead of adding them one by one. Then you change the address in the station’s settings so it reports to ELVO, and the station connects, announces itself and shows as online against the record you created.

If you have several brands across several sites, the same messages arrive from all of them. A card presented at any station is authorised with the same request. Meter values arrive in the same shape. Status changes are reported the same way. So one list and one export cover the whole fleet. From the platform you start and stop a session, reset a station, unlock a connector and read or write a configuration value on any brand. What still differs is which configuration keys a model exposes and what it calls them, which is a firmware question rather than a protocol one.

If you want the connection encrypted, ELVO takes the secure form, a WebSocket connection over TLS written as wss, and the security extension on our certificate covers it. The station side depends on its own firmware, so ask your vendor.

If a station drops off the connection, you see it as offline in the station list. From the same screen you can reset a station, unlock a connector, start or stop a session, or push a firmware update. A fault does not have to turn into a trip across town.

What you can charge per connector, and how stations share one supply, have their own articles: charging billing and how many stations a building can take.

ELVO is compatible with 700+ charger models, holds the Open Charge Alliance certificate named above, and you can open an account and connect a station without talking to anyone.

What to ask before you buy, and how to test it

The first five are questions for the station vendor. The last two you do yourself.

1. Ask which OCPP version the model speaks, and in which form. The answer decides which platforms the model can work with.
2. Ask for the certificate number covering that exact model, then look it up in the public register. The register of certified products is free to search. A model can sit on an existing certificate as part of a product family, which is normal. Ask for the number, and for confirmation that your model is on that certificate.
3. Ask whether the firmware does TLS with client authentication, and from which firmware version. Get the answer in writing, because it differs between models from the same manufacturer.
4. Ask whether the platform address can be changed remotely or only at the station. If you can only change it at the station, your next platform move costs a lot more.
5. Ask which OCPP messages the model implements, by name. Remote start and stop, reset, unlock connector, charging profiles and firmware update are the ones you will use. A datasheet that says only “OCPP compliant” has not answered.
6. Point one station at a trial account and check that status, energy and a remote command all come back. One station, one address, half an hour. Every other step is someone telling you it works. This one shows you.
7. Move the rest one site at a time. If a model behaves differently from the one you tested, you find that out on one site instead of on all of them.

Frequently asked questions

What is OCPP in EV charging?

OCPP is the open communication protocol between charging stations and charging management systems. It is published by the Open Charge Alliance and the specification can be downloaded from their site, with or without an account. A station that speaks OCPP can be connected to any management system that speaks it.

Which OCPP versions are there, and which one do stations use?

Three versions are available: OCPP 1.6 from 2015, OCPP 2.0.1 from 2020 and OCPP 2.1 from 2025. OCPP 1.6 is still the version you meet on stations already installed. OCPP 1.6 and OCPP 2.0.1 are not compatible, so the station and the platform have to meet on the same one.

What does an OCPP certificate actually cover?

It covers one tested product on one side of the connection. Certificates are issued against OCPP 1.6 or OCPP 2.0.1, by independent laboratories, separately for a charging station and for a management system. There is no certification program for OCPP 2.1. Core is mandatory; smart charging and advanced security are named separately.

Does OCPP mean I can change platform without changing my stations?

That is the practical point of OCPP. A station reports to whatever platform address you give it, so changing that address moves it to the new platform, with its serial number and its connectors. That address sits in a different place on every model, so ask before you buy. The stations stay where they are.

Does the law require OCPP?

No European rule mentions OCPP by name. The alternative fuels regulation requires publicly accessible points to be digitally connected, and those built after 13 April 2024 or renovated after 14 October 2024 to be capable of smart recharging. The buildings directive has member states require non-proprietary protocols. OCPP is how the industry delivers both.

Is the OCPP connection encrypted?

Only when both sides set it up that way. The secure form is a WebSocket connection over TLS, written as wss, and the certification program lists TLS with client authentication as its own item. Ask your station vendor whether your model’s firmware does it.

Read next and resources

Read next: OCPP backend: what it is and how to choose one picks up where this article stops, when you are choosing the software instead of learning the protocol. OCPP charger compatibility covers what to check on a specific model before you order it.

Sources:

• Open Charge Alliance, OCPP protocol page
• Open Charge Alliance, download the specifications
• Open Charge Alliance, the OCPP certification program
• Open Charge Alliance, register of certified products
• Open Charge Alliance, OCPP Certification Procedure
• Open Charge Alliance, certification mark misuse
• Open Charge Alliance, OCPP achieves international standard status
• Regulation (EU) 2023/1804 on the deployment of alternative fuels infrastructure
• Directive (EU) 2024/1275 on the energy performance of buildings
• ELVO certificate OCA.0016.1071.CSMS

Try it on one station

The fastest way to see what OCPP gives you is to use it once, on one station, and read the first session that comes back. Start a 30-day free trial, no commitment, cancel anytime. If you decide against it, you change that one setting back.

ELVO Team. We operate CPMS for manufacturers, distributors, installers, and operators across Europe and beyond.

Published 25 August 2026.