How EV Charging Cards Work
RFID, apps, roaming and OCPI explained simply
An EV charging card gives you access to multiple charging networks with a single card and account. Instead of downloading a different app for every network, you tap one card or open one app. Behind the scenes, a technology called OCPI connects everything together.
What Is an EV Charging Card?
An EV charging card is a small RFID card (like a contactless bank card) that you tap on a chargepoint to start a charging session. The card is linked to your account with a charging provider like Electroverse, Zapmap, or Shell Recharge. When you tap, the charger communicates with the provider's system, verifies your account, and starts the session. You get billed through your provider, not the individual network. Some providers also offer app-based payment as an alternative to the physical card.
How RFID Works at a Chargepoint
Tap your card
Hold your RFID card against the card reader on the chargepoint. This is usually marked with a contactless symbol or "tap card here" label.
Charger verifies your account
The chargepoint reads your card's unique ID and sends it to the network operator. The operator checks with your card provider (e.g. Electroverse) that your account is valid and has a payment method.
Charging starts
Once verified (usually 5-15 seconds), the charger unlocks the cable and begins charging your car. A green light or screen message confirms the session has started.
You get billed later
When you end the session (or unplug), the charger reports the kWh used to your card provider. You receive a single bill from your provider, not from the individual network.
What Is Roaming?
Roaming in EV charging works like mobile phone roaming. When you use a phone abroad, your home network connects to a foreign network so you can make calls. Similarly, when your Electroverse card accesses a BP Pulse charger, Electroverse "roams" onto BP Pulse's network to let you charge. You only have an account with Electroverse, but you can use chargers operated by hundreds of different networks. The networks have commercial agreements to accept each other's customers. This is why a single card can access 950+ networks.
What Is OCPI?
OCPI (Open Charge Point Interface) is the technical standard that makes roaming possible. It is a shared language that different charging networks and card providers use to communicate. OCPI handles real-time chargepoint availability, pricing information, session authorisation, and billing data. Without OCPI, every network would be an isolated island and you would need a separate account for each one. OCPI is the reason one Electroverse card can work on InstaVolt, BP Pulse, GRIDSERVE and hundreds of other networks — they all speak the same language.
Cards vs Apps vs Contactless
You have three ways to pay at most public chargers. RFID cards are the fastest and most reliable — just tap and charge, no phone needed. Apps give you more information (pricing, session tracking) but require your phone. Contactless bank cards are the simplest but often the most expensive, as you pay the network's PAYG rate without any loyalty or subscription discounts. Many experienced EV drivers carry an RFID card as their primary payment method and keep apps as backup.
Key Takeaway
An EV charging card simplifies public charging by giving you one card, one account, and one bill across hundreds of networks. The RFID tap-and-charge experience is the fastest and most reliable way to start a session.
Frequently Asked Questions
Not strictly — you can use contactless at most chargers. But a charging card saves money (through discounts), simplifies billing (one account for all networks), and works at chargers that don't accept contactless.
Most public chargers in the UK have RFID readers. However, some (like Tesla Superchargers) are app-only. Your card provider's app will show which chargers support RFID.
Yes. Many drivers carry two or three cards from different providers. This gives access to the widest range of networks and lets you compare prices for the best deal at each location.
Usually 5-15 seconds. You tap the card, wait for the green light or screen confirmation, and charging starts. It is generally faster than using an app.