Charging roaming is the ability for EV drivers to start and pay for charging sessions across different charging networks using a single contract, app, RFID card, or vehicle-based authentication. It connects CPOs (charge point operators) and eMSPs (e-mobility service providers) through roaming platforms or bilateral agreements, enabling broader access and higher charger visibility.
What Is Charging Roaming?
Charging roaming works similarly to mobile phone roaming: the driver has an account with one provider (often an eMSP) but can charge on many independent networks operated by different CPOs.
Instead of creating a new account for every network, the driver can:
– Use an eMSP app or RFID card to authenticate
– Start a session on a third-party CPO charger
– Pay through their eMSP contract, while settlement happens in the background between companies
Why Charging Roaming Matters
Roaming is a major driver of EV charging adoption because it reduces friction and improves accessibility. For operators and site hosts, it can increase station usage and unlock new customer channels.
Key benefits include:
– Better driver experience with fewer apps and contracts
– Higher charger utilization through expanded user reach
– Improved network visibility in major mobility apps and maps
– Faster scale for CPOs entering new regions without building a full customer base
Roaming is also essential for cross-border charging, where local networks may be unfamiliar to visiting drivers.
Key Players in Charging Roaming
Roaming ecosystems typically include:
– CPO (Charge Point Operator): owns and operates the chargers, sets availability, and delivers the energy
– eMSP (E-mobility Service Provider): owns the customer relationship, billing, and app/RFID access
– Roaming platform/hub: connects multiple CPOs and eMSPs, enabling tariff exchange, authentication, and settlement
– CPMS (Charge Point Management System): the backend system that controls chargers and communicates roaming status
How Charging Roaming Works
A typical roaming session follows these steps:
– Driver authenticates via eMSP app, RFID, or Plug & Charge (where supported)
– Charger sends an authorization request through the CPO backend
– The request is routed to the eMSP via a roaming platform or direct connection
– Authorization is approved or declined based on the customer’s contract status
– Charging starts, and session data (kWh, time, costs) is recorded
– The eMSP bills the driver and pays the CPO through settlement rules (minus fees/commission)
Roaming Standards and Protocols
Roaming relies on standardized data exchange, so different systems can interoperate. Common building blocks include:
– OCPP for charger-to-backend communication (within the CPO’s network)
– Roaming protocols for CPO–eMSP data exchange (tariffs, locations, sessions, tokens)
– ISO 15118 for advanced vehicle-based authentication (Plug & Charge) when supported by both backend and hardware
Even with standards in place, roaming quality depends heavily on proper configuration, tariff setup, and backend implementation.
Commercial Model: Tariffs, Markups, and Settlement
Roaming pricing is rarely identical to direct-channel pricing. Common approaches:
– CPO provides a base tariff; eMSP adds a markup for customer service, risk, and platform costs
– Settlement includes roaming platform fees and sometimes transaction fees per session
– Some agreements include minimum margins or different rates by location type
For CPOs, roaming can increase volume but reduce margins if commissions are high or tariffs are not carefully structured.
Operational Challenges in Charging Roaming
Roaming can introduce complexity that impacts driver experience and revenue realization:
– Tariff mismatches and price display inconsistencies
– Session start failures due to token syncing issues
– Delays in availability updates (charger shows “available” but is actually offline)
– Disputes around billing, refunds, and chargebacks
– Data reconciliation issues between the CPO and the eMSP session records
High uptime, stable connectivity, and well-tested backend integrations are critical for reliable roaming.
When Roaming Is Most Valuable
Roaming is especially useful when:
– A network is expanding and needs fast utilization growth
– A site depends on occasional users (highways, travel corridors, destination sites)
– Cross-border traffic is significant
– Fleet drivers require broad access without multiple local contracts
For mature networks, roaming is often balanced with direct customer acquisition to protect margin.
Related Glossary Terms
Roaming
eMSP (E-mobility Service Provider)
CPO (Charge Point Operator)
OCPP
ISO 15118
Plug & Charge
Charging Session Revenue
Charging Revenue Models
Uptime