In a method for accessing voice or data services via a mobile telephony network, a communication device provided with wireless communication means detects within radio range communication terminals equipped with authentication means to connect to a mobile telephone network, selects a communication terminal to be used for accessing the network, by polling the terminal owner, sets up a wireless communication with the selected communication terminal, uses the latter's authentication means to set up a connection with the network, determines by polling the user of the communication terminal whether a terminal is authorized to access the voice or data services via the communication device and the connection it has set up with the network, and refuses access to the voice or data services if the terminal is not authorized.