When people start in EV charging, they quickly meet two acronyms that seem to describe the same thing: CPO and eMSP. Both are involved when a driver charges a car, both can have an app and both send invoices. Yet they play different roles, earn money in different ways and face different risks.
This guide explains each role, shows how they work together when a driver charges on another company's network, and helps you decide which role, or combination, fits your business.
- A CPO (charge point operator) runs the charging infrastructure: chargers, uptime, pricing at the charger and site relationships.
- An eMSP (e-mobility service provider) runs the driver relationship: apps, cards, contracts and driver billing.
- Roaming connects the two, so drivers of one eMSP can charge at many CPOs' chargers.
- Many companies act as both, but the roles remain separate in data flows and settlement.
What is a charge point operator (CPO)?
A CPO is responsible for operating charging stations. It may own them or operate them on behalf of a site owner. Typical responsibilities include:
- Installing, commissioning and maintaining chargers.
- Connecting chargers to a charging station management system (CSMS) over OCPP and monitoring them.
- Setting prices at the charger, including ad hoc prices for drivers without a contract.
- Publishing location, availability and price data.
- Meeting technical and legal requirements, such as payment and metering rules.
The CPO earns money from energy sold, either directly from ad hoc drivers or indirectly through eMSPs that pay for their customers' sessions. If you are considering this role, see our guide on how to become a charge point operator.
What is an e-mobility service provider (eMSP)?
An eMSP provides charging access to drivers. It does not need to own a single charger. Typical responsibilities include:
- Offering an app, RFID card or key fob that drivers use to start charging.
- Showing a map of available chargers across many networks.
- Managing driver contracts, subscriptions and customer support.
- Invoicing drivers for sessions on any network they used.
- Negotiating roaming agreements with many CPOs.
The eMSP earns a margin between what it pays the CPO and what it charges the driver, plus any subscription fees. Car manufacturers, energy suppliers, fuel card companies and fleet service providers often act as eMSPs.
Side-by-side comparison
| Aspect | CPO | eMSP |
|---|---|---|
| Main asset | Charging infrastructure | Driver customer base |
| Main customer | Drivers at its chargers, site hosts, eMSPs | Drivers and fleets |
| Revenue | Energy sales, idle fees, site services | Charging margin, subscriptions, fleet services |
| Key systems | CSMS, OCPP, payment terminals | Driver app, billing, customer database |
| Main risks | Utilisation, uptime, grid costs | Customer acquisition, roaming prices |
| Capital intensity | High | Low to medium |
How CPOs and eMSPs work together
Imagine a driver with an app from eMSP A who arrives at a charger operated by CPO B. The session works like this:
- Authorisation: the driver taps a card or starts the session in the app. The charger sends an authorisation request to CPO B's CSMS, which checks with eMSP A whether the token is valid.
- Charging: CPO B's system records the session, energy and duration from the charger's meter values.
- Session record: when the session ends, CPO B sends a charge detail record to eMSP A.
- Billing: eMSP A invoices the driver according to its own tariff.
- Settlement: CPO B invoices eMSP A according to their roaming agreement, either directly or through a roaming hub.
The data exchange between CPO and eMSP systems typically uses OCPI, an open protocol designed for exactly this purpose. Our guide to OCPI explains the details, and our article on OCPI vs OCPP shows how it differs from the protocol between charger and CSMS.
Direct connections or roaming hubs?
CPOs and eMSPs can connect in two ways:
- Peer-to-peer: each pair of companies signs a contract and connects their systems directly. This gives more control but takes effort for every partner.
- Through a hub: both connect once to a roaming platform that handles many partners, contracts and settlement. This is faster to scale but adds fees.
Many operators combine both: direct connections with their largest partners and a hub for the long tail.
Being both CPO and eMSP
Many companies play both roles. A charging network with its own app is a CPO for its chargers and an eMSP for its app users, who may also charge elsewhere through roaming. Benefits include a direct relationship with drivers and better margins on your own chargers. The cost is more systems, more customer support and the need to manage roaming in both directions.
Which role suits your business?
| If you are... | Likely role |
|---|---|
| A site owner or investor with land and grid capacity | CPO, possibly with an operator partner |
| An energy supplier with many retail customers | eMSP, often also CPO |
| A fleet service or fuel card company | eMSP for fleet drivers |
| A hotel, retailer or parking company | Site host or CPO for own sites |
| An installer or electrical contractor | CPO services under your own brand, using a white-label platform |
Frequently asked questions
Can a CPO sell charging directly to drivers without an eMSP?
Yes. Through ad hoc payment by card or QR code, or through its own app, a CPO can serve drivers directly. Roaming with eMSPs simply adds more customers.
Does an eMSP need its own chargers?
No. An eMSP can offer access to thousands of chargers it does not own through roaming agreements with CPOs.
Who sets the price the driver pays?
For ad hoc charging, the CPO sets the price. For drivers using an eMSP app or card, the eMSP sets the driver price, while the CPO charges the eMSP an agreed roaming tariff.
What is the difference between eMSP and MSP?
They usually mean the same thing. MSP (mobility service provider) and eMSP are used interchangeably in EV charging.
Run your chargers as a CPO and connect to eMSPs through OCPI roaming from one platform. Explore Üreticy OCPP software or contact us to discuss your business model.