The Open Clearing House Protocol (OCHP) supports data exchange between charge point operators and mobility service providers through a clearing house. The OCHP uses a stable message format to move information about roaming, sessions, tariffs, contracts, and charge point status. The OCHP also enables roaming across networks through a hub that forwards requests and responses between connected parties.
The Open Clearing House Protocol maintains core functions such as roaming authentication, pricing exchange, contract validation, session reporting, and settlement support. The OCHP strengthens the EV ecosystem through structured communication that links distributed systems and removes bilateral integrations. The OCHP differs from the OCPI, the OCPP, and the eMIP because the Open Clearing House Protocol focuses on hub-based clearing, while the other protocols focus on peer communication, charger control, or direct roaming. The Open Clearing House Protocol delivers benefits through consistent data handling, but it faces limitations due to slower adoption and reduced flexibility compared to the OCPI. The OCHP requires basic implementation steps such as hub connection, endpoint setup, certificate handling, and data model alignment. Monta positions itself toward protocols with wider adoption, so Monta prioritises the OCPI for roaming and the OCPP for charger control rather than the OCHP.
What is the open clearing house protocol (OCHP)?
The Open Clearing House Protocol (OCHP) is an open protocol for e-mobility clearing between charging station operators and mobility service providers. The Open Clearing House Protocol solves interoperability and cross-network roaming by giving both parties a shared method to exchange contracts, tariffs, and session data. The OCHP supports organizations such as charge point operators, e-mobility service providers, and roaming hubs because these actors need a stable way to move charging information across networks.
The Open Clearing House Protocol maintains core functions such as contract authentication, session data exchange, tariff distribution, and charge detail record transfer. The OCHP uses message categories for roaming requests, authorization, metering data, and settlement-related information. The Open Clearing House Protocol differs from the OCPI and the eMIP because the OCHP uses a hub-based clearing approach, while the OCPI uses peer communication and the eMIP uses a different message architecture for roaming. The Open Clearing House Protocol gains strength from being open-source, vendor-neutral, and standardized across roaming hubs because these properties reduce lock-in and support broader participation.
How does the OCHP work?
The Open Clearing House Protocol (OCHP) works through standardized data exchange between mobility service providers, charging station operators, and a clearing house. The OCHP moves information through structured messages that handle authentication, roaming validation, tariff distribution, session data transmission, and charge detail record delivery.
The Open Clearing House Protocol routes communication through the hub instead of direct peer exchange, so the clearing house receives each request, validates the contract, and forwards the message to the correct mobility service provider. The Open Clearing House Protocol verifies tokens by sending authorization data through the hub, publishes tariffs through tariff messages, and reconciles sessions by delivering metering and session summaries.
The OCHP triggers a flow when an EV user starts a roaming session. The Open Clearing House Protocol sends the token to the clearing house, receives the validation result, and begins the session once the contract is confirmed. The OCHP then sends session updates, metering values, and end-of-session records to the clearing house, which forwards them to the mobility service provider. The Open Clearing House Protocol maintains interoperability by using one data model for all actors and protects data integrity by enforcing consistent message formats and routing rules across operators.
What are the key functions and features of the OCHP?
The key functions and features of the OCHP are listed below.
- Roaming and interoperability: The OCHP enables roaming through shared message rules that link operators and mobility service providers and maintain cross-network compatibility.
- Tariff and pricing data: The Open Clearing House Protocol distributes tariff information so that roaming partners receive clear pricing structures for billing and transaction handling.
- Contract and user identification: The clearing house verifies tokens and validates contracts by using standardized identification fields across networks.
- Session information handling: The OCHP transfers session status, metering values, and timestamps so that roaming sessions remain synchronized between systems.
- Reporting, billing and settlement: The Open Clearing House Protocol forwards charge detail records and supports settlement flows by giving operators consistent billing data.
- Charge point information exchange: The OCHP shares availability, status, and technical attributes of charging stations so that service providers maintain accurate operational data.
Roaming and interoperability
The OCHP solves roaming challenges by giving mobility service providers and charging station operators one structured method to validate contracts and authorize users across networks. The Open Clearing House Protocol enables cross-network recognition by sending authorization requests through the clearing house, matching tokens to valid contracts, and returning clear acceptance or rejection messages. The OCHP demonstrates interoperability through message flows where roaming requests, session starts, metering updates, and end-of-session data move through the clearing house and reach the correct mobility service provider without bilateral integrations.
The Open Clearing House Protocol reduces fragmentation because operators follow the same data model and avoid custom roaming agreements that often fail during authorization or settlement. The OCHP strengthens roaming reliability for operators because each roaming action uses consistent fields, message formats, and routing rules. The Open Clearing House Protocol benefits EV drivers by giving them predictable authorization outcomes when they charge on another network.
Tariff and pricing data
The OCHP manages tariff and pricing data by giving mobility service providers and charging station operators one model for distributing prices used in roaming transactions. The Open Clearing House Protocol standardizes price communication by sending tariff messages through the clearing house, where structured fields define energy rates, time-based elements, and additional cost components. The OCHP reduces tariff mismatches by enforcing one pricing format, which prevents operators from sending incomplete or inconsistent values that would otherwise lead to billing disputes.
The Open Clearing House Protocol improves pricing accuracy because all roaming partners receive the same tariff information before a session begins, which strengthens trust in billing outcomes. The OCHP supports operators and mobility service providers by keeping tariff data synchronized across networks, which lowers manual corrections and reduces settlement errors.
Contract and user identification
The OCHP manages contract and user identification by using tokens and contract identifiers that mobility service providers register in the clearing house. The Open Clearing House Protocol verifies contracts by routing authorization requests through the clearing house, where the token is checked against active contract records maintained by the mobility service provider. The OCHP ensures secure authentication by enforcing structured identification fields and by requiring clear acceptance or rejection responses before a session begins.
The Open Clearing House Protocol reduces roaming errors because correct token validation prevents unauthorized sessions and avoids mismatches between users and contracts. The OCHP supports fraud prevention by rejecting tokens that do not match active roaming agreements. The Open Clearing House Protocol improves continuity for EV drivers because validated contracts enable immediate authorization on external networks.
Session information handling
The OCHP manages session information by collecting data such as session status, consumption values, and timestamps from charging station operators during roaming. The Open Clearing House Protocol structures these updates into defined message formats that the clearing house forwards to the mobility service provider in real time. The OCHP keeps session data consistent by enforcing fixed fields and standardized time formats so that both parties receive identical information.
The Open Clearing House Protocol improves reporting accuracy because operators no longer rely on custom data exports that often create mismatches. The OCHP strengthens roaming reliability by giving mobility service providers clear visibility into session progress and final consumption values. The Open Clearing House Protocol increases operational efficiency because synchronized data reduces manual reconciliation across networks.
Reporting, billing and settlement
The OCHP manages financial records by handling charge detail records that contain consumption values, timestamps, pricing elements, and session identifiers. The Open Clearing House Protocol supports accurate settlement between mobility service providers and charging station operators by sending these records through the clearing house in standardized formats. The OCHP reduces billing discrepancies because consistent data fields remove variations that often cause reconciliation failures.
The Open Clearing House Protocol improves transparency since operators receive the same financial information for each roaming session, which reduces the need for manual corrections. The OCHP strengthens trust in the roaming ecosystem because predictable settlement flows support scalable cooperation between networks.
Charge point information exchange
The OCHP transmits charge point information such as availability, operational status, connector details, and basic technical attributes of each EVSE. The Open Clearing House Protocol keeps this data accurate by using standardized message formats that operators send to the clearing house whenever station conditions change. The OCHP synchronizes availability and status by forwarding these updates to mobility service providers so that external platforms maintain the same view of each charging point.
The Open Clearing House Protocol improves reliability for roaming users because accurate station data reduces failed charging attempts caused by outdated information. The OCHP supports operational planning for networks since consistent EVSE data helps operators track usage patterns, schedule maintenance, and manage roaming expectations across connected regions.
What is the role of the OCHP in the EV-ecosystem?
The role of the OCHP is to serve as a structured link between mobility service providers, charging station operators, and clearing houses in the EV-charging ecosystem. The Open Clearing House Protocol supports interoperability by giving all parties one communication model for roaming, authorization, pricing exchange, session reporting, and settlement. The OCHP reduces data fragmentation because each roaming action uses consistent message fields that prevent mismatches between networks and strengthen cross-network reliability.
The Open Clearing House Protocol simplifies roaming by using one method for contract validation, tariff distribution, session data flow, and charge detail record transfer. The OCHP enables scalable infrastructure since operators no longer depend on bilateral roaming agreements that limit expansion and increase integration effort. The Open Clearing House Protocol strengthens the e-mobility environment by giving EV drivers predictable access to charging across networks, regardless of which service provider manages the session.
The OCHP supports market alignment because every operator uses the same definitions for identification, tariffs, and session values, which improves accuracy when roaming volume increases. The Open Clearing House Protocol reinforces network consistency by giving clearing houses a central role in routing messages, validating data, and preventing errors that occur when operators implement custom roaming setups. The OCHP increases ecosystem stability because unified communication rules reduce failed authorizations, inconsistent pricing, and incomplete session data, which strengthens trust between roaming partners and improves service continuity for EV drivers.
What are the different OCHP versions?
The different OCHP versions are listed below.
- OCHP 1.2: An early stable release providing the foundational message structure for roaming, contract handling, and basic session exchange.
- OCHP 1.3: Introduced refinements to message definitions, improved roaming interoperability, and clarified tariff and charge detail record handling.
- OCHP 1.4: Expanded support for enhanced EVSE information exchange, more consistent tariff models, and improved settlement data workflows.
- OCHP 1.5: Latest widely referenced version including extended data fields, higher interoperability alignment with emerging roaming standards, and improved error handling and validation logic.
OCHP 1.2
The OCHP 1.2 release acted as the baseline protocol version because it introduced the initial roaming framework, early contract validation, and the first charge detail record schema. The Open Clearing House Protocol 1.2 established the foundational architecture by defining a single message structure that operators could use for roaming authorization, session initiation, and basic financial reporting through the clearing house. The OCHP 1.2 version delivered enough stability for early roaming deployments since it removed custom integrations, but it lacked the data refinements and schema clarity that later versions introduced.
The Open Clearing House Protocol 1.2 constrained feature set limited interoperability because message fields were fewer, error handling was less precise, and EVSE information was not fully standardized. The OCHP 1.2 release remains important in the protocol’s historical progression because it set the structural model that all later versions expanded and aligned with broader roaming requirements.
OCHP 1.3
The OCHP 1.3 release delivered schema refinement that improved the clarity of the 1.2 specification by tightening message definitions for tariffs, contract logic, and identification fields. The Open Clearing House Protocol 1.3 addressed earlier ambiguities by clarifying how tariff elements were structured, how contract states were validated, and how session-related messages should be interpreted across roaming partners. The OCHP 1.3 version strengthened interoperability because clearer semantics reduced variation in how clearing-house partners processed authorization, pricing, and reporting data.
The Open Clearing House Protocol 1.3 increased operational stability since mobility service providers and charging station operators no longer faced mismatched interpretations of key values. The OCHP 1.3 release acted as a protocol stabilization milestone rather than a major functional expansion because it focused on semantic clarification and reduced ambiguity instead of adding new capabilities.
OCHP 1.4
The OCHP 1.4 release introduced an expanded feature set that added new data fields and broader message coverage, extending the protocol beyond the earlier versions. The Open Clearing House Protocol 1.4 enriched EVSE metadata by including more detailed station attributes, expanded tariff components through an extended tariff model, and improved settlement workflows with clearer financial and metering elements. The OCHP 1.4 updates strengthened interoperability because operators could exchange more precise technical details and handle roaming scenarios that required deeper insight into pricing and station availability.
The Open Clearing House Protocol 1.4 broadened protocol coverage as emerging operator requirements demanded richer metadata and more accurate settlement data for complex business cases. The OCHP 1.4 release improved operational workflows by giving mobility service providers and charging station operators greater visibility into station characteristics and by increasing charge detail record accuracy through more structured input fields. The Open Clearing House Protocol 1.4 stands out as a meaningful expansion point in the protocol’s evolution because it moved beyond refinement and introduced broader roaming capabilities that supported more mature roaming operations.
OCHP 1.5
The OCHP 1.5 release introduced a modernized schema that strengthened alignment with contemporary roaming expectations and improved the protocol’s readiness for large-scale deployments. The Open Clearing House Protocol 1.5 enhanced validation logic, expanded error handling rules, and increased message completeness so operators could exchange data with fewer inconsistencies. The OCHP 1.5 version also improved cross-protocol alignment with ecosystems shaped by the OCPI and the eMIP, reducing interpretation gaps between roaming frameworks.
The Open Clearing House Protocol 1.5 reduced integration friction because clearer validation paths and more predictable error responses helped partners diagnose issues faster and maintain stable data exchange. The OCHP 1.5 release increased protocol robustness by enforcing stricter schema requirements that prevented missing fields, malformed values, and incomplete CDR structures. The Open Clearing House Protocol 1.5 strengthened scalability and partner compatibility because operators could rely on consistent message behavior, which lowered long-term maintenance effort. The OCHP 1.5 version stands as the most mature and widely referenced iteration since it delivers the enhanced validation framework and improved robustness that roaming ecosystems require today.
What is the difference between the OCHP and the OCHPdirect?
The OCHP differs from the OCHPdirect because the OCHP uses a clearing-house–mediated communication model, while the OCHPdirect uses direct messaging between charging station operators and mobility service providers. The OCHP routes roaming, contract validation, and session data through a hub, which handles message distribution and settlement flows between many partners. The OCHPdirect sends messages such as start, stop, and status updates directly between a charging station operator and a mobility service provider, which supports real-time control of charge points.
The OCHP supports roaming interoperability, tariff exchange, charge detail record handling, and multi-party settlement across networks that connect to the same clearing house. The OCHPdirect focuses on live operations, including remote start and stop, live status, and direct authorization flows between a specific operator and a specific service provider. The OCHP hub-based architecture suits large roaming networks that need scalable partner management and unified settlement, while the OCHPdirect suits scenarios where low latency and tight operational control matter more than broad interoperability. The OCHP and the OCHPdirect therefore fit different use cases, so operators should evaluate roaming strategy, network size, and integration resources before selecting one approach or combining both in a wider EV-charging setup.
How does the OCHP compare to the OCPI, the OCPP, and the eMIP?
The OCHP uses a clearing-house–mediated roaming model, while the OCPI follows a peer-to-peer roaming architecture, the OCPP focuses on device-level charge point control, and the eMIP offers another roaming-focused interchange framework. The OCHP clearing house platform routes roaming messages, contract checks, and settlement data through a hub that connects many partners. The OCPI links operators and mobility service providers directly through bilateral or multi-party connections without a central hub. The OCPP manages communication between charge points and backend systems, so the OCPP does not handle roaming or settlement. The eMIP supports hub-based roaming through a different message design and role model that focuses on mobility data exchange and contract management.
The OCHP and the eMIP align in scope because both support hub-based roaming, contract validation, tariff exchange, and charge detail record flows. The OCPI differs because the OCPI focuses on direct interoperability, flexible modules, and high configurability between specific parties. The OCPP stands apart by providing device-level control, firmware updates, meter values, and event handling for chargers without defining roaming flows. The OCHP delivers structured settlement and tariff exchange using fixed data models and charge detail record formats, while the OCPI offers a more flexible module system that lets partners shape roaming and pricing in different ways. The eMIP provides its own roaming and contract validation workflows that resemble clearing-house operations but follow distinct message semantics and role definitions.
The OCHP shows strengths in interoperability and scalability for hub-based networks because one integration connects an operator to many partners through the OCHP clearing house system. The OCPI performs well when operators want fine-grained control over peer relationships and when latency and direct routing matter more than centralized governance. The OCPP delivers strong operational control at the device level but does not resolve roaming or settlement challenges on its own. The eMIP suits environments where a mobility-focused hub and its specific data model already exist or where regional regulations reference the eMIP. The OCHP selection should depend on network architecture, roaming strategy, real-time control needs, and regulatory context, so many operators combine the OCPP for device control, the OCPI or the eMIP for some roaming flows, and the OCHP for hub-based roaming and structured settlement where a clearing house platform uses the OCHP standard.
What are the main benefits of the OCHP?
The main benefits of the OCHP are listed below.
- Improved roaming interoperability: The OCHP gives mobility service providers and charging station operators one structured method for authorization, pricing exchange, and session data flow, which reduces fragmented integrations.
- Higher operational consistency: The Open Clearing House Protocol enforces standardized message formats that keep contract validation, tariff distribution, and charge detail record handling aligned across partners.
- Reduced friction in billing and settlement: The OCHP lowers reconciliation effort because unified data fields and clear settlement records minimize discrepancies between operators.
- Scalability for expanding networks: The Open Clearing House Protocol’s hub-based model allows operators to connect once to a clearing house and reach many partners without building separate roaming agreements.
- Better charging experiences for EV drivers: The OCHP improves authorization reliability and session accuracy, which strengthens cross-network charging availability.
- Vendor-neutral participation: The Open Clearing House Protocol supports open and accessible integration for operators, enabling broad adoption without vendor lock-in.
What are the biggest limitations of the OCHP?
The biggest limitations of the OCHP are listed below.
- Reduced flexibility compared to newer roaming standards: The OCHP uses a fixed schema that limits extensibility when operators need custom fields or evolving data structures.
- Dependence on clearing-house mediation: The Open Clearing House Protocol routes all roaming actions through a hub, which increases latency and reduces direct interoperability compared to peer-based systems like the OCPI.
- Limited support for real-time control: The OCHP does not handle low-latency operations such as direct start or stop commands, which reduces its suitability for dynamic operational workflows.
- Lower ecosystem adoption in recent years: The Open Clearing House Protocol has seen slower growth compared to the OCPI, which has become the common choice for flexible roaming integrations across many markets.
- Operational constraints for large-scale innovation: The OCHP’s structure makes it harder for operators to experiment with new pricing models, advanced metadata, or high-frequency updates.
- Strategic considerations for long-term use: The Open Clearing House Protocol may not align with operators seeking rapid expansion, multi-regional interoperability, or tight real-time integration with backend platforms.
What are the main steps for OCHP implementation?
The main steps for OCHP implementation are the following.
- 1. Assess requirements and select OCHP version: Determine business goals, roaming needs, and compatibility with versions from OCHP 1.2 to OCHP 1.5 based on clearing-house and partner capabilities.
- 2. Map internal data models: Align backend data for contracts, tariffs, EVSE metadata, and session logs with the message structures defined by the Open Clearing House Protocol.
- 3. Develop the OCHP interface: Implement the required endpoints, authentication logic, and standardized message formats defined by the OCHP specification.
- 4. Integrate with the clearing house: Configure routing, credentials, and connectivity to the clearing-house hub that mediates roaming exchanges.
- 5. Test message workflows: Validate tariff exchange, contract verification, session updates, charge detail record creation, and error-handling routines in controlled testing conditions.
- 6. Synchronize EVSE and contract data: Ensure station metadata, contract identifiers, and pricing models match the structures required by the Open Clearing House Protocol before moving to production.
- 7. Perform interoperability and load testing: Confirm stable message routing, scalability under load, and correct interaction with partner mobility service providers and charging station operators.
- 8. Go live and monitor performance: Launch production operations, track message accuracy, verify settlement consistency, and adjust configurations based on operational feedback.
Does Monta support OCHP? (And how does it position itself among roaming protocols?)
The Monta platform does not provide direct support for the OCHP, and it does not integrate natively with clearing-house systems that rely on the OCHP for roaming.
Monta positions itself around the OCPI for roaming because the OCPI supports peer-to-peer connections, modular data exchange, and broad adoption among operators and mobility service providers. Monta relies also on the OCPP for charger control because the OCPP delivers the device-level communication required for remote start, stop, smart charging, and firmware updates.
The Monta system architecture works best when roaming, device communication, and settlement flows follow standards designed for scalable direct integrations, so the platform maintains compatibility with roaming ecosystems through the OCPI and operational control through the OCPP. Monta benefits charge point operators because direct OCPI connections reduce latency, simplify partner setup, and minimise dependencies on clearing-house mediation. The platform avoids fragmentation by using roaming channels that offer clear tariff exchange, contract validation, and session data handling without relying on hub-based routing. The Monta approach strengthens interoperability by focusing on standards that evolve quickly, attract wide adoption, and support flexible use cases for both mobility service providers and charging station operators, while still enabling cooperation with partners that use OCPI-based roaming across diverse charging networks.