Roaming payments are the billing and settlement processes that allow an EV driver to pay for charging on a foreign or third-party network using their home provider account—without registering or paying directly with the local charge point operator (CPO). The driver is billed by their e-mobility service provider (eMSP) (via app, contract, or RFID charging card), and the eMSP then settles payment with the CPO according to the roaming agreement.
Roaming payments enable interoperability, but they add extra steps, fees, and reconciliation requirements compared to direct payments.
Why Roaming Payments Matter
Roaming payments affect:
– Driver convenience (one account across many networks)
– Pricing transparency (roaming markups and fee structures)
– CPO revenue and margin (wholesale settlement terms and roaming fees)
– Operational workload (CDR reconciliation, disputes, delayed settlements)
– Risk of revenue leakage if sessions are not settled correctly
For cross-border travel and fleets, roaming payments are often essential.
How Roaming Payments Typically Work
A standard roaming payment flow looks like this:
– Driver authenticates at the CPO charger using an eMSP token (app/QR/RFID)
– The CPO authorizes charging using roaming connectivity (often via OCPI)
– The charging session runs, and the CPO records energy (kWh), time, and location
– The CPO generates a charge detail record (CDR) after session completion
– The CPO sends the CDR to the eMSP (directly or through a hub)
– The eMSP bills the driver (or fleet) based on its retail tariff and rules
– The eMSP pays the CPO based on the agreed wholesale price and settlement cycle
– Any roaming fees, markups, VAT/tax handling, and refunds follow the contract rules
Who Pays Whom in Roaming Payments
Roaming payments usually split into two layers:
– End-user payment
– Driver pays the eMSP (often postpaid invoice, stored payment method, or wallet)
– Inter-company settlement
– eMSP pays the CPO using wholesale rates and settlement rules defined in the roaming agreement
– A roaming hub may charge additional fees or facilitate settlement and reconciliation
This is why a “paid” session from the driver perspective can still be “unsettled” from the CPO’s perspective until the CDR is accepted and paid.
Common Roaming Payment Models
– CPO tariff pass-through + eMSP markup
– eMSP adds a service fee to the CPO price
– Wholesale rate settlement
– CPO charges the eMSP a fixed wholesale tariff; eMSP sets retail price independently
– Hybrid fees
– Per-session fees, per-kWh fees, minimum charges, and/or time-based fees layered into settlement
Operational Risks and Failure Points
Roaming payments can fail or leak revenue due to:
– CDR rejection (missing fields, incorrect EVSE IDs, inconsistent timestamps)
– Session not converted into a billable CDR due to offline sync issues
– Tariff mismatch between what was displayed and what was billed
– Token authorization mapping errors causing session ownership confusion
– Delayed settlement cycles causing cashflow delays
– Currency and VAT issues in cross-border settlements
– Disputes and refunds requiring manual handling and corrections
Best Practices for Reliable Roaming Payments
– Monitor CDR acceptance rate and partner-specific rejection reasons
– Reconcile sessions vs CDRs and settlements to detect missing or unpaid transactions
– Maintain consistent EVSE ID and connector mapping across systems
– Use clear definitions for gross vs net revenue in revenue reporting
– Implement retry logic and idempotent CDR submissions in roaming APIs
– Track roaming margin separately from direct customer margin
Related Glossary Terms
Roaming
Roaming fees
Roaming agreements
Roaming APIs
OCPI
Charge detail records (CDRs)
RFID charging cards
Revenue reporting
Revenue leakage detection
Interoperability billing