Methods are described for charging fees in a road toll system. An on-board unit identification is input into a toll terminal to generate a transaction identification. The transaction identification is transmitted to a transaction server, and from the server to a transaction terminal. A payment card identification is input into the transaction terminal, and is transmitted with the transaction identification to the server. A substitute identification, generated in the transaction server and associated with the card identification, and the transaction identification are transmitted from the transaction server to the toll terminal. The on-board unit identification and substitute identification, associated by the transaction identification, are transmitted from the toll terminal to a toll server. The substitute identification is used in a communication between the toll server and the transaction server for charging a fee for a location usage determined in the road toll system under the respective on-board unit identification.