OCPP, the Open Charge Point Protocol, is the open communication standard that lets your home EV charger talk to any back-end management system, regardless of who made either one. Maintained by the Open Charge Alliance (OCA), it is the practical mechanism behind UK smart charging compliance, tariff switching, and dynamic load management. This guide explains how OCPP works, which version to look for in 2026, how it connects to UK regulations, and which home chargers support it properly.
OCPP matters to UK drivers because it prevents vendor lock-in. Without it, switching energy supplier or moving to a smarter tariff could mean replacing your entire charger. With it, your hardware stays compatible as the market evolves, your tariff changes, and new standards emerge.
What Is OCPP?
OCPP stands for Open Charge Point Protocol. It is an open, vendor-neutral standard that defines how a charge point (your charger) communicates with a Central Management System (CSMS), the cloud back-end run by your supplier, your charger brand, or a network operator.
Think of it as a shared language. Before OCPP, every charger manufacturer spoke its own dialect. A supplier wanting to schedule overnight charging had to build a separate integration for each charger brand. OCPP standardised the conversation so that any OCPP-compliant charger can connect to any OCPP-compliant CSMS.
The Open Charge Alliance publishes and maintains OCPP free of charge. It is not owned by any manufacturer or energy company, which is precisely what makes it useful as an interoperability standard.
OCPP enables:
- Remote start and stop of charging sessions
- Real-time metering data sent to the back-end
- Scheduled charging via charge profiles (SetChargingProfile)
- Firmware updates pushed from the management system
- Dynamic load management across multiple chargers
- Smart tariff integration for time-of-use scheduling
- Roaming between networks
Why OCPP Matters for UK Home EV Drivers
For most UK drivers, OCPP is invisible. You plug in, your charger starts at the off-peak time your tariff specifies, and you unplug in the morning with a full battery. OCPP is what makes that automation possible behind the scenes.
Here is why it matters when you are buying a charger:
1. Tariff freedom. If your charger only integrates with one supplier via a proprietary connection, switching to a better overnight tariff might mean replacing the hardware. OCPP-compliant chargers can connect to any compatible CSMS, which means you can move between Intelligent Octopus Go, E.ON Next Drive, OVO Charge Anytime, or any future tariff without touching your charger.
2. Smart tariff scheduling. Tariffs like Intelligent Octopus Go adjust your charging window dynamically based on grid conditions. OCPP is the protocol that carries those scheduling instructions from the supplier’s system to your charger. Without OCPP (or an equivalent direct API), your charger cannot receive those updates automatically.
3. Roaming and network access. OCPP underpins smart charge networks including Octopus Electroverse, letting you access public charging with a consistent experience across different hardware.
4. Regulatory compliance. From 30 June 2022, every home and workplace charger sold in Great Britain must meet the smart functionality requirements of the Electric Vehicles (Smart Charge Points) Regulations 2021. OCPP is the primary way manufacturers deliver the interoperability and grid-protective behaviour those regulations require.
5. Future readiness. OCPP 2.0.1 and the newer 2.1 standard carry V2G messaging, tariff display, and deeper integration with energy management systems. Buying a charger with an OCPP endpoint today leaves you positioned for whatever comes next.
You can read the government’s guidance on smart charge point regulations at GOV.UK. For the specific tariffs that currently use OCPP scheduling, see our guide to OCPP and smart tariff integration.
OCPP and UK Smart Charge Point Regulations
The Electric Vehicles (Smart Charge Points) Regulations 2021, which came into force for home and workplace chargers from 30 June 2022, set mandatory smart functionality requirements for all new charge points sold in Great Britain. Understanding these regulations helps explain why OCPP has become the de facto standard in the UK market.
What the regulations require:
- Demand-side response. Chargers must be capable of adjusting their charging rate in response to a signal from a grid operator, energy supplier, or CSMS.
- Default off-peak restriction. Chargers must ship with a default schedule that avoids charging during the peak periods of 8–11am and 4–10pm on weekdays.
- Randomised delay. When responding to a start signal, the charger must introduce a randomised delay of up to 10 minutes to prevent thousands of vehicles starting simultaneously.
- Measurement and data. Chargers must be capable of metering energy at a specified accuracy and making that data available.
- Cyber security. From 30 December 2022, all new chargers must comply with ETSI EN 303 645, the consumer IoT cyber security standard.
OCPP is not explicitly named in the regulations, but it is the practical implementation route for most of these requirements. The demand-side response capability maps directly to OCPP’s SetChargingProfile message. The metering requirement maps to MeterValues. Cyber security compliance for OCPP 2.0.1 is supported through TLS transport, which is mandatory in that version.
When you see a charger described as “regulation-compliant” in the UK, OCPP is almost always how it gets there. Proprietary implementations exist but are increasingly rare as the market consolidates around open standards.
The full text of the regulations is available from legislation.gov.uk.
OCPP Versions Compared: 1.6J vs 2.0.1 vs 2.1
Not all OCPP is equal. The version your charger runs determines which features are available and whether it can connect to next-generation management systems. Here is how the three current versions compare:
| Version | Transport | Security | Device model | Smart charging | ISO 15118 / PnC | V2G messaging | UK prevalence |
|---|---|---|---|---|---|---|---|
| OCPP 1.6J | JSON over WebSocket | Optional TLS | Flat | SetChargingProfile | No | No | Dominant |
| OCPP 2.0.1 | JSON over WebSocket | Mandatory TLS | Hierarchical | Enhanced profiles | Yes | Yes | Growing |
| OCPP 2.1 (2025) | JSON over WebSocket | Mandatory TLS | Hierarchical | Tariff management | Yes | Yes | Emerging |
OCPP 1.6J remains the most widely deployed version in the UK home charger market. Released in 2015 and using a flat data model, it is simple, well-understood, and supported by virtually every CSMS and home charger on the market. For day-to-day smart tariff scheduling, 1.6J is sufficient. Its limitation is in security: TLS is optional rather than required, and there is no native support for ISO 15118 Plug and Charge.
OCPP 2.0.1 was approved as an IEC standard (IEC 63584) in 2024 and represents a significant architectural upgrade. It introduces a hierarchical device model (network, station, connector), mandatory TLS for all communications, richer smart charging profile support, tariff display on the charger itself, and ISO 15118 support enabling Plug and Charge. It also carries the messaging framework for V2G. The two versions are not backward-compatible: a 2.0.1 CSMS cannot talk to a 1.6J charger directly without a translation layer.
OCPP 2.1 (published 2025) adds dedicated tariff management capabilities, which allow the charger to display live pricing and running session costs to the driver. This is the version aligned with the EU’s growing smart charging requirements and anticipated UK alignment.
For UK home charger buyers in 2026, OCPP 1.6J remains a practical and compliant choice. If you plan to adopt V2G or want the most future-proof hardware available, look for chargers with OCPP 2.0.1 support or explicit 2.0.1-ready firmware roadmaps.
OCPP and Smart Tariffs
OCPP is the mechanism that lets your energy supplier schedule your home charger automatically. When you enrol in a time-of-use tariff, the supplier’s system (running a CSMS) sends a SetChargingProfile message to your charger via its OCPP connection. The charger stores that schedule and follows it, starting and stopping charging according to the off-peak window, regardless of whether your app is open or your phone has signal.
In practice, different suppliers take different approaches:
- Octopus Intelligent Go works with certain charger brands (Ohme, Zappi, Hypervolt, Indra) via a direct API integration with Octopus’s Kraken platform, rather than a generic OCPP CSMS. Other OCPP chargers can connect to Octopus via third-party management platforms. The result is the same: automatic scheduling that adjusts dynamically as grid conditions shift.
- E.ON Next Drive and OVO Charge Anytime use OCPP-compatible scheduling for their smart charging features across a wider range of hardware.
OCPP 2.0.1 adds on-charger tariff display, so drivers can see the current rate and session cost directly on the unit. OCPP 2.1 extends this with dedicated tariff management messaging, enabling real-time per-kWh pricing shown before and during a session.
For a full breakdown of how OCPP carries price signals to your charger, see our article on OCPP and smart tariff integration.
OCPP and Dynamic Load Management
If you have a heat pump, a large oven, and an EV charger all on the same 100 A supply, running all three simultaneously could trip your main fuse. Dynamic Load Management (DLM) solves this by throttling the charger’s output in real time based on what the rest of the house is drawing.
OCPP is what makes this possible at a protocol level. The DLM controller, typically running as a lightweight CSMS or a local scheduler, reads a CT clamp on the main incomer and issues SetChargingProfile messages to adjust the charger’s output. As household demand rises (say, the oven turns on), the charger’s allowance drops. When demand falls, the charger ramps back up.
This same mechanism scales to multi-charger households. If you have two EVs and two chargers, OCPP allows a common controller to share the available capacity across both units dynamically, rather than each charger fighting independently for headroom.
For homes with heat pumps, battery storage, or solar panels, DLM via OCPP is not a luxury. It is practical grid-awareness built into how your energy assets communicate. For a detailed explanation of how DLM works, see our guide to dynamic load management for EV chargers.
Is Your Charger OCPP-Compatible? How to Check
“Smart charging” on a spec sheet does not automatically mean OCPP. Some manufacturers lock smart features behind their own proprietary app and do not expose an OCPP endpoint at all, or they gate OCPP access for commercial or installer accounts only.
Before you buy, work through this checklist:
- Look for an explicit OCPP version on the spec sheet. The phrasing should be “OCPP 1.6J” or “OCPP 2.0.1”, not just “OCPP compatible” or “smart charging”. Vague wording often means proprietary-only.
- Ask whether the OCPP endpoint is open or gated. Some chargers (Zaptec, certain Rolec models) require the installer to request OCPP credentials from the manufacturer or a commercial portal. For personal home use, confirm the process before purchase.
- Confirm it is not a paid add-on. A small number of brands charge for OCPP access as a commercial upgrade. Verify this before assuming it is included in the residential price.
- Check tariff compatibility explicitly. If you plan to use Intelligent Octopus Go, check whether your chosen charger is listed on Octopus’s compatible hardware list, or whether you need to use a third-party management platform to bridge the connection.
OCPP vs OCPI vs OICP vs ISO 15118
These four protocols often appear together in EV charging discussions, and they are frequently confused. They do different jobs at different points in the charging ecosystem:
| Protocol | Governs | Used between |
|---|---|---|
| OCPP | Charge point to management system | Your charger and the supplier’s / network’s back-end |
| OCPI | Roaming between networks | Two charge point operators’ back-end systems |
| OICP | Similar roaming, Hubject-based | CPO back-ends (European focus) |
| ISO 15118 | Vehicle to charge point | Your EV and the charger itself |
OCPP is the vertical connection from charger to cloud. It is what most home charging discussion refers to.
OCPI (Open Charge Point Interface) handles horizontal roaming, enabling drivers to use one account or app across multiple public networks. This is the protocol that makes a roaming aggregator like Octopus Electroverse possible.
OICP (Open Intercharge Protocol) is a competing roaming standard operated by Hubject, more common in mainland Europe.
ISO 15118 operates at a completely different layer: the cable between your car and the charger. It enables Plug and Charge (automatic EV authentication without a card or app) and vehicle-to-grid communication. OCPP 2.0.1 explicitly includes ISO 15118 integration, which is how future home chargers will support both protocols in the same unit.
For the full picture on ISO 15118 and Plug and Charge, see our Plug and Charge / ISO 15118 guide.
Best UK Home Chargers with OCPP Support
These are the home chargers currently available in the UK that offer verified OCPP access rather than proprietary-only smart charging:
- Zaptec Go 2 — OCPP 1.6J, open endpoint available via Zaptec’s portal. Three-phase ready, Nordic design, PEN fault protection built in.
- Rolec EVO — OCPP 1.6J on request, widely specified by UK installers. British-built in Lincolnshire.
- NexBlue Point 2 — OCPP 1.6J standard, compatible with Intelligent Octopus Go. Strong value at its price point.
- Ohme Home Pro — Native Intelligent Octopus Go integration via Kraken, plus OCPP support. Built-in display and cable management.
- MyEnergi Zappi — OCPP 1.6J, plus native solar diversion via CT clamp (Eco and Eco+ modes).
- Hypervolt Home 3 — OCPP on request, Alexa and Google Home integration, LED indicator ring.
For the complete ranked shortlist with specs, pricing, and tariff compatibility, see our best OCPP-compatible home chargers guide.
Key Takeaways
- OCPP is the open protocol that lets your home EV charger talk to any management system, preventing vendor lock-in.
- From 30 June 2022, UK-sold home chargers must meet smart charging regulations; OCPP is the most common way manufacturers deliver this.
- OCPP 1.6J is still the mainstream version in 2026; 2.0.1 and the new 2.1 add tariff display and V2G messaging.
- OCPP enables tariff switching (Intelligent Octopus Go, E.ON Next Drive) and dynamic load management for multi-EV driveways.
- OCPP is distinct from ISO 15118, which governs the car-to-charger conversation for Plug and Charge.
- Always check the spec sheet for an explicit OCPP version rather than the generic “smart” label.
Frequently Asked Questions
What does OCPP stand for? OCPP stands for Open Charge Point Protocol. It is an open, vendor-neutral standard maintained by the Open Charge Alliance (OCA), a Dutch non-profit. The protocol is free to download and use, which is why it has become the dominant standard for EV charger interoperability worldwide.
Is OCPP mandatory for UK home chargers? OCPP itself is not legally mandated. However, the Electric Vehicles (Smart Charge Points) Regulations 2021 require smart functionality, including demand-side response, randomised delay, and metering capability. OCPP is the de facto way manufacturers deliver these requirements. A charger could theoretically comply via a proprietary system, but OCPP is by far the most common implementation in the UK market.
What is the difference between OCPP 1.6 and OCPP 2.0.1? OCPP 1.6J uses a flat data model, optional TLS security, and does not natively support ISO 15118 or V2G. OCPP 2.0.1 introduces a hierarchical device model, mandatory TLS, richer smart charging profiles, on-charger tariff display, ISO 15118 support for Plug and Charge, and V2G messaging. The two versions are not backward-compatible: a 2.0.1 system cannot communicate directly with a 1.6J charger without translation.
Does OCPP cost the customer anything? The OCPP standard itself is free. Whether you pay to use it depends on the charger manufacturer. Some brands include a fully open OCPP endpoint as standard in the residential product. Others gate OCPP access behind an installer portal, a commercial account, or an optional upgrade. Always confirm this before purchase.
Is OCPP the same as Plug and Charge? No. OCPP handles communication between your charger and the cloud management system. Plug and Charge, defined by ISO 15118, handles the direct conversation between your EV and the charger itself, enabling automatic authentication by certificate exchange over the charging cable. OCPP 2.0.1 integrates with ISO 15118, but they operate at different layers of the charging ecosystem.
Useful Resources
Open Charge Alliance — official OCPP documentation https://openchargealliance.org/
GOV.UK — Smart Charge Point Regulations guidance https://www.gov.uk/guidance/regulations-electric-vehicle-smart-charge-points
The Electric Vehicles (Smart Charge Points) Regulations 2021 — full legislation text https://www.legislation.gov.uk/ukdsi/2021/9780348228434
ChargeLab — OCPP 1.6 vs 2.0.1 comparison https://chargelab.co/blog/ocpp-1.6-vs-ocpp-2.0.1-key-differences-for-ev-charging-csms-and-charger-firmware
ETSI EN 303 645 — Consumer IoT security standard https://www.etsi.org/deliver/etsi_en/303600_303699/303645/