OCPP is the mechanism that lets your energy supplier schedule your home EV charger automatically. When you enrol in a smart overnight tariff, the supplier’s management system sends a SetChargingProfile message to your charger via its OCPP connection. Your charger stores the schedule and follows it — starting, pausing, and resuming charging according to the off-peak window — without you opening an app or touching a switch.
This is how Intelligent Octopus Go, E.ON Next Drive, OVO Charge Anytime, and every other UK EV smart tariff delivers automatic scheduling. Understanding the mechanism tells you which charger to buy, why some work better than others, and what to expect as the market moves to OCPP 2.0.1.
For background on the protocol itself, see our full OCPP EV charging guide. For a comparison of the best UK smart tariffs, compare the best UK EV smart tariffs.
How Smart Tariffs Work in the UK
UK EV smart tariffs fall into two broad categories: fixed off-peak windows and dynamic windows.
Fixed off-peak tariffs (OVO Charge Anytime, E.ON Next Drive) offer a guaranteed lower rate during a set overnight window, typically midnight to 6am or similar. The charger receives a schedule aligned to this window and charges within it.
Dynamic off-peak tariffs (Intelligent Octopus Go) adjust the charging window in real time based on grid conditions, carbon intensity, and wholesale prices. On a quiet night with high wind generation, the window might extend further. On a stressed grid, it narrows. The charger must receive updated schedules continuously.
Here is how the three main UK smart tariffs compare in terms of control mechanism:
| Tariff | Off-peak structure | Dynamic? | Control method |
|---|---|---|---|
| Intelligent Octopus Go | Moving window (typically 11pm–7am region but adaptive) | Yes | Native Kraken API (select chargers) or OCPP via CSMS |
| E.ON Next Drive | Fixed off-peak window | No | OCPP via CSMS |
| OVO Charge Anytime | Fixed off-peak window + flat fee | No | OCPP or app schedule |
Tariff structures change regularly — verify current details with the supplier before switching. Figures vary.
The OCPP Message Flow for Smart Charging
When your supplier schedules your charger, three OCPP message types do most of the work:
1. SetChargingProfile This is the core scheduling message. The supplier’s Central Management System (CSMS) sends a SetChargingProfile command that defines when and at what rate the charger should operate. A profile might say: “Between 23:30 and 06:30 tomorrow, charge at up to 7,400 W. Outside that window, charge at 0 W.”
The charger stores this profile locally. Even if your broadband drops at midnight, the charger already has its instructions.
2. MeterValues While charging, the charger sends back MeterValues at regular intervals — typically energy consumed, current power draw, and session duration. This data feeds into the supplier’s billing system and lets the app show you live session status.
3. TransactionEvent (OCPP 2.0.1) or StartTransaction / StopTransaction (1.6J) These messages open and close the billing record for each charging session. They carry session identifiers that let the supplier credit any applicable smart tariff discounts to your account.
The sequence in practice:
- You plug in at 9pm. The charger starts a session record.
- Your supplier’s CSMS detects the plug-in event and checks your tariff schedule.
- The CSMS issues SetChargingProfile: charge at 0 W until 23:30, then at full rate until 06:00.
- At 23:30, the charger ramps up automatically. MeterValues stream back every few minutes.
- At 06:00, the charger ramps down. You unplug in the morning with a full battery.
OCPP 2.0.1 adds the ability to display the current tariff rate on-charger in real time, so you can see whether you are in the cheap window from the unit itself, not just the app.
Intelligent Octopus Go: Direct API vs OCPP Path
Intelligent Octopus Go is the UK’s most sophisticated residential EV tariff, and it takes a more nuanced approach to charger integration than a generic OCPP scheduler.
Kraken-native integration — Ohme Home Pro, MyEnergi Zappi, Hypervolt, and Indra Smart Pro connect directly to Octopus Energy’s Kraken platform via a manufacturer-specific API. This gives the tightest possible integration: Octopus can see session data in real time, adjust the charging window dynamically based on live grid conditions, and handle exceptions (such as a full battery or a manual override) without relying on a generic OCPP scheduling cycle.
OCPP-via-management platform — Other OCPP-compatible chargers (Zaptec Go 2, Rolec EVO, NexBlue Point 2) can integrate with Intelligent Octopus Go via a third-party management platform that bridges between Octopus’s system and the charger’s OCPP endpoint. The functionality is broadly equivalent, but the integration is less tightly coupled.
Note: whether Octopus Energy has shipped a native OCPP CSMS as of 2026 or continues to route via Kraken-native integrations and third-party bridges is an active area of development — verify current documentation with Octopus before assuming your specific charger’s integration path.
The practical upshot for buyers: if Intelligent Octopus Go is your primary tariff, check whether your chosen charger is on Octopus’s explicitly listed compatible hardware page. If it is, the integration is tested and supported. If it is not, you may need to use a management platform as an intermediary.
E.ON Next Drive and OVO Charge Anytime via OCPP
E.ON Next Drive offers a fixed off-peak window and uses OCPP scheduling to align charging with it. Compatible chargers connect to E.ON’s management system and receive SetChargingProfile commands that restrict charging to the off-peak period. The tariff does not require the adaptive, real-time control of IOG, so a standard OCPP 1.6J integration is sufficient.
Verify the current compatible charger list at eonnext.com — the list updates regularly.
OVO Charge Anytime works on a similar model, combining a flat per-charge fee with off-peak overnight scheduling. OVO provides scheduling control via OCPP or via its app for chargers that support app-based time control. As with E.ON, OCPP 1.6J is the baseline requirement.
Verify the current compatible charger list at ovoenergy.com — figures vary and charger compatibility changes with app updates.
OCPP 2.0.1 and 2.1 Tariff Messaging
As the UK market moves towards OCPP 2.0.1, the tariff integration capabilities of home chargers will improve significantly.
OCPP 2.0.1 introduces:
- On-charger tariff display. The current per-kWh rate can be shown on the charger’s screen before a session starts, so you know exactly what you will pay.
- Running cost tracking. The session cost can be displayed in real time on units with a screen.
- Enhanced smart charging profiles. More granular scheduling options, with multiple tariff periods in a single profile.
OCPP 2.1 (published 2025) goes further with dedicated tariff management messages, enabling suppliers to push live pricing data that the charger can act on autonomously. This is the protocol layer that will underpin truly dynamic, real-time charging optimisation as wholesale prices become more granular.
For now in 2026, OCPP 1.6J covers all current UK smart tariff functionality. Buyers who want to be positioned for the next generation of dynamic tariffs should look for chargers with OCPP 2.0.1 hardware capability or confirmed upgrade roadmaps.
Common Integration Gotchas
These are the issues UK installers most commonly encounter when setting up OCPP smart tariff integrations:
1. Charger assigned to two management systems simultaneously. Some chargers shipped by installers come pre-configured with the installer’s management portal endpoint. If you then enrol in Octopus or E.ON’s scheduling system, the charger may be pointed at two CSMS endpoints, causing conflicts. Confirm with your installer that only one active CSMS endpoint is configured.
2. OCPP endpoint locked behind installer account. Several brands (including Zaptec and certain Rolec configurations) require the installer to request and activate the OCPP endpoint. If the installer does not complete this step, your charger’s OCPP connection may be inactive even if the hardware supports it. Ask your installer to confirm OCPP activation before they leave the job.
3. Firmware level blocking smart-charging schedules. Some older firmware versions on current-generation chargers have bugs that prevent SetChargingProfile from working correctly. Always check that your charger is running the current firmware release before troubleshooting tariff integration issues.
Will OCPP Unlock V2G Tariffs in the Future?
OCPP 2.0.1 explicitly supports bidirectional energy flow messaging, which is a prerequisite for vehicle-to-grid (V2G) tariffs. As UK V2G trials mature and commercial V2G products reach the market, OCPP 2.0.1 will be the protocol layer that carries the discharge schedules from a supplier’s management system to the charger and back.
This means that buyers choosing a charger in 2026 with OCPP 2.0.1 hardware are not just future-proofing for better scheduling; they are positioning for potential V2G revenue in the future, provided the vehicle and charger combination supports bidirectional energy flow.
Read our full OCPP EV charging guide
Compare the best UK EV smart tariffs
Key Takeaways
- OCPP is what lets your supplier schedule your home charger without you doing anything manual.
- Intelligent Octopus Go usually runs via a native Kraken API for certain charger brands; others integrate via a third-party OCPP management platform.
- OCPP 2.0.1 adds on-charger tariff display; OCPP 2.1 introduces dedicated tariff management messages.
- Always check that your charger is assigned to only one CSMS at a time to avoid scheduling conflicts.
- OCPP-based V2G integration is coming to UK smart tariffs through 2.0.1 adoption as the market develops.
Frequently Asked Questions
Does OCPP work with Intelligent Octopus Go? Yes, though the path depends on your charger. Ohme Home Pro, MyEnergi Zappi, Hypervolt, and Indra have native Kraken API integrations. Other OCPP 1.6J chargers can integrate via third-party management platforms. Check Octopus’s current compatible charger list to confirm your model’s specific integration route before enrolling.
Can I be on two smart tariffs at once? No. A home charger’s OCPP endpoint connects to one CSMS at a time. If you enrol in two tariffs that each try to control your charger, you will have a scheduling conflict. Choose one smart tariff, confirm the integration is active, and only then switch if you want a different tariff later.
Does OCPP 2.0.1 change my bill? Not directly — your tariff rate determines what you pay per kWh. OCPP 2.0.1 enables your charger to display the current rate and running session cost on the unit itself, which improves transparency. The scheduling capabilities it enables may allow suppliers to offer more optimised tariff windows in future, which could indirectly reduce costs.
Do I need OCPP to use Octopus Intelligent Go? Not necessarily. If your charger has a native Kraken integration (Ohme, Zappi, Hypervolt, Indra), it communicates directly with Octopus without going via a standard OCPP CSMS. For other chargers, OCPP is the integration route. If your charger has neither, it cannot participate in Intelligent Octopus Go’s dynamic scheduling.
Does OCPP help with solar self-consumption? Indirectly. OCPP can carry setpoints from a management system that reads local solar generation, adjusting the charger’s rate to use surplus PV. However, most solar diversion on home chargers (Zappi Eco+, Indra Smart Pro) uses local CT clamp logic that operates independently of the OCPP cloud connection, making it faster and more responsive to generation changes.
Useful Resources
Intelligent Octopus Go https://octopus.energy/smart/intelligent-octopus-go/
OVO Charge Anytime https://www.ovoenergy.com/electric-cars/charge-anytime
E.ON Next Drive tariff https://www.eonnext.com/ev/ev-tariffs
Ampcontrol — OCPP smart charging guide https://www.ampcontrol.io/ocpp-guide/how-to-use-smart-charging-with-ocpp
AMPECO OCPP Handbook 2026 https://www.ampeco.com/guides/complete-ocpp-guide/