OCPP explained: how your charger talks to apps, tariffs and back offices

A home charger is only as useful as the software it talks to: the manufacturer’s app, your energy supplier’s smart tariff, your employer’s back office or a home energy manager. The common language between charger and software is usually OCPP – and whether your charger speaks it openly decides how much freedom you have later.

What is OCPP?

The Open Charge Point Protocol is an open communication standard between a charging station and a central management system, often called the back office. It is maintained by the Open Charge Alliance, which has more than 400 members worldwide – charger manufacturers, software providers and network operators – and aims for interoperable charging infrastructure across vendors ¹.

With an open OCPP connection, you can move the charger to another back office – for example when you change job, switch to a tariff that controls chargers, or fit a home energy manager – without replacing the hardware.

Is it required by law?

No. The Smart Charge Points Regulations 2021 require home chargers to be smart and secure, but do not prescribe a protocol; OCPP is one way to meet the requirements ². Many chargers sold in the UK rely on the manufacturer’s own cloud instead, with or without an OCPP option.

The versions

OCPP 2.0.1 was also adopted as international standard IEC 63584 in 2024 ³.

What our data shows

We know the OCPP version for 51 of the 67 chargers in our database. Of those, 11 (22%) support OCPP 2.0.1; the rest support 1.6 or 1.6J. Eight models are recorded as OCA-certified; the Open Charge Alliance runs a certification programme with test labs and a database of certified products ¹. A charger can support OCPP without certification – certification means a lab has tested the implementation.

For most homes, OCPP 1.6J is enough. Look for 2.0.1 if you plan to keep the charger for many years, your employer requires it, or you are interested in Plug & Charge and, later, vehicle-to-home.

Who does what

• Manufacturer – makes the charger and usually provides an app and cloud.
• Charge point operator / back office – manages chargers remotely: updates, faults, sessions and pricing.
• Tariff or service provider – may control the charger (directly or through the manufacturer’s cloud) to charge when electricity is cheapest.
• eMSP / charge card provider – issues cards and apps for public charging and bills you.

At home, most people only use the manufacturer’s app. A back office comes in when someone else pays: an employer, a landlord or a block of flats sharing chargers.

Common uses at home

1. Company car: the employer’s or fleet provider’s back office reads your sessions via OCPP for reimbursement; see our guide on company car home charging.
2. Smart tariff or energy manager: controls when and how fast the car charges, from price signals or solar surplus.
3. Flats and shared parking: one back office shares power between bays and assigns sessions to residents via RFID. 55 of the 67 chargers in our data have an RFID reader.

On the road: cards, apps or contactless

The Public Charge Point Regulations 2023 set rules for public chargers in the UK, including contactless payment on new public chargers of 8 kW and above, prices shown in pence per kWh, and a free 24/7 helpline ⁴. A charge card or app is therefore no longer the only way to pay, but can still be handy for a single monthly bill or business expenses.

Plug & Charge (ISO 15118)

With ISO 15118 the car identifies itself over the charging cable and the session starts without a card or app. It needs support in the car, the charger and the back office. Five chargers in our database list ISO 15118: see EV chargers with ISO 15118. For bidirectional charging, the standards point to ISO 15118-20 combined with OCPP 2.1 ³.

Questions to ask before buying

• Which OCPP version, and is it open to any back office or only to the manufacturer’s partners?
• Does charging (and load balancing) still work without the cloud if the internet drops?
• How does it connect – Wi-Fi, Ethernet or 4G? 40 models in our data have 4G: EV chargers with 4G.
• Are there subscription fees for the app, back-office connection or OCPP access?
• How long will the manufacturer supply security and firmware updates?

Compare every charger and its OCPP support on the EV charger overview.