Charging roaming — where a user of one vehicle brand charges and pays seamlessly at a station of another operator — is the condition for the Vietnamese charging network to escape the one-brand-one-app-one-wallet fragmentation. Legally, roaming needs no separate licence, but it needs a standard contract framework on clearing payment, service levels and customer data; this article builds that framework.
Legal basis
- The roaming relationship is a service contract relationship between the charging station operator (CPO) and the end-user service provider (eMSP, usually a vehicle brand or an app platform), governed by the Civil Code 2015 and the Commercial Law on service supply, payment and service quality responsibility.
- Charging service prices and metering of power sold to end users must comply with price listing and verification of measuring instruments used in payment under the Law on Prices 16/2023 and the Law on Measurement 04/2011 — applying at the charging point regardless of whether the user arrives through a roaming channel or directly.
- Law on Personal Data Protection 91/2025/QH15 and Decree 356/2025/ND-CP (replacing Decree 13/2023/ND-CP): sharing customer data between roaming parties must have a legal basis, serve the payment and service purposes, and apply corresponding data protection measures.
How is payment made when one brand vehicle charges at another station?
The roaming payment mechanism operates in three layers. The user layer: the driver authenticates at a station of operator B using the app, card or account of brand A (their own eMSP), the charging session is recorded with data on power volume, time and charging point; the driver pays under the price schedule published for that session — either the listed price of station B or the service package price of brand A depending on the contract model — through the wallet or payment method registered with brand A, without creating a new account at B. The inter-enterprise clearing layer: periodically (usually monthly), the parties reconcile all roaming sessions, brand A collects user money and pays operator B the charging revenue portion minus the roaming fee and platform fee as agreed; multi-directional differences among many operators are handled through one clearing payment focal point or an intermediary roaming platform connecting many CPOs and eMSPs. The technical data layer: session data is exchanged through open connection protocols between the systems of the parties (the market commonly uses the OCPP protocol between station and management system, and roaming protocols between platforms) — this is a voluntary market technical standard, the law does not impose one specific protocol, but the roaming contract must lock the applied connection standard and responsibility where session data is wrong, because this data is the payment basis. The price the end user sees must comply with price listing at the charging point and in the app, avoiding a surprise roaming price higher than the direct price without prior notice.
What clauses does a charging roaming contract need?
Eight clause groups form the cooperation contract framework for shared charging infrastructure. First, connection scope: the list of stations and charging posts joining roaming, the technical connection standard and the integration testing process before opening to users. Second, price and fee model: the price applied to roaming users (station price or eMSP package price), roaming fees and platform fees, the price change mechanism and prior notice. Third, reconciliation and clearing payment: the reconciliation cycle, session data as the basis, payment deadlines, disputed session handling and late payment interest. Fourth, service levels (SLA): the minimum charging post availability ratio, incident remedy time, end-user support and the allocation of responsibility where a user of one side meets an incident at a station of the other. Fifth, incident liability allocation: damage to vehicles, persons and property in a roaming session is handled on the fault principle at the charging point, with duties to cooperate in supplying log data and corresponding insurance. Sixth, customer data: the shared data scope limited to data needed for authentication, payment and customer care, use purposes, retention periods, security measures and a ban on using roaming data for competitive marketing without separate user consent. Seventh, brand and user experience: price display, invoices for end users and cross-system complaint handling. Eighth, term, termination and data transition: ensuring users face no sudden service interruption where a party leaves the network, and data deletion and return duties after termination.
Does sharing customer data in roaming breach the law?
It does not breach where the sharing is designed correctly under the personal data protection regime; it breaches where sharing exceeds the needs of the transaction. Under the Law on Personal Data Protection 91/2025 and Decree 356/2025, session data tied to user identity (account, plate number, charging point location, charging history) is personal data; roaming parties may share only the data fields needed for session authentication, charging and reconciliation — typically an encrypted user identifier, session data and payment status — on the basis that the user was informed and consented to roaming service use in the service terms of the eMSP, or another suitable legal basis under law. Three conducts are clearly prohibited in roaming design: selling or exchanging roaming customer data for purposes outside the service; using the location and charging history data of a partner customer base for customer-poaching marketing without separate consent; and retaining shared data indefinitely without corresponding security. The roaming contract must therefore carry a personal data processing annex allocating the controller and processor roles, and each party bears its own responsibility before the authority and users for the data portion it holds. Where the network has a cross-border element (a roaming platform with servers abroad), duties on outbound personal data transfer must also be assessed separately.
Deployment recommendations for operators and vehicle brands
A practical roadmap comprises: starting with a framework agreement with one partner whose station coverage complements yours instead of waiting for a perfect network; running technical and reconciliation pilots on a small data set before commercial opening; publishing roaming prices transparently to users right in the app; and reviewing the data annex whenever the sharing scope expands. Roaming succeeds commercially only where it is clean on payment and data — the two points deciding the trust of both partners and users.
Frequently asked questions
How is payment made when one brand vehicle charges at another station?
Through the three-layer roaming mechanism: the driver authenticates with their own brand account at the partner station and pays the published tariff through the registered wallet; between enterprises, the driver brand collects user money and periodically clears payment to the station operator for the revenue minus roaming fees based on session data; session data is exchanged via open connection protocols between systems and forms the reconciliation basis.
What clauses does a charging roaming contract need?
Eight core groups: station scope and connection standards; the price model for roaming users and roaming fees; reconciliation, clearing payment and disputed session handling; SLA service levels and user support; incident liability allocation at the charging point; customer data limited to authentication and payment needs with security; brand, price display and complaints; and term, termination with data transition and deletion.
Does sharing customer data in roaming breach the law?
Not if only data needed for authentication, billing and reconciliation is shared on the basis of user notice and consent in the service terms, with security measures under the Law on Personal Data Protection 91/2025 and Decree 356/2025. It breaches where data is sold outside the service purpose, partner customer data is used for poaching marketing without separate consent, or data is retained indefinitely without security.
This article has been quality-reviewed by the FLAW AI Legal Council