How does Plug & Charge work?

The car carries a contract certificate and presents it to the charger over the cable. The backend checks it, and charging starts without a card or app.

Explained in

Plug & Charge · Stop 01What changes when the car identifies itself?No card, no app: with Plug & Charge, the car proves which contract it charges under, and the session starts on plugging in.

Plug & Charge automates communication and billing between car and charger, without external means of identification such as charging cards or apps; ISO 15118 defines the interfaces for it. The driver still has a contract with a provider. The car carries proof of that contract, a certificate, and presents it when it is plugged in.

From “Automated, not anonymous”, stop 01

Terms

  1. ISO 15118International standard for the digital communication between car and charger, the basis of Plug & Charge.
  2. Plug & ChargeThe car identifies itself with a certificate when plugged in, so no card or app is needed.
  3. Contract certificateA certificate in the car that binds the driver's contract ID to a key only the car holds, used for Plug & Charge.
  1. Who issues Plug & Charge certificates?Certificate authorities that operate V2G roots, with trust lists that let several roots work together. CharIN coordinates governance but does not operate a PKI.
  2. Why does Plug & Charge not work at every charger?Car, charger, backend, contract and trust all have to support it. If one is missing, the session starts with a card or app instead.
  3. What is ISO 15118-20?The second generation of ISO 15118, published in 2022. It adds bidirectional power transfer, wireless communication and automatic connection; a 2026 amendment adds megawatt charging and grid services.
  4. What is in a Plug & Charge certificate?A subject with the eMAID, an issuer, a validity period, a public key and the issuer's signature, chained through the provider's sub-CAs to a V2G root the charger trusts. The deep dive prints one chain and the four checks the backend runs on it.
  1. CharIN: Plug & Charge at CharIN: standardised and interoperable. https://www.charin.global/technology/plug-charge/. Checked 09 Oct 2026.