A method is for controlling entry, e.g., into a motor vehicle, during which a key and a base station wirelessly exchange authentication data between one another in an active or a passive communication mode. At the beginning of the authentication process, the base station transmits a call signal to the key, and the key replies to the call signal with a reply signal. The base station verifies the received reply signal of the key in the communications mode in which the reply signal was received. If the reply signal of the key was received in the active communications mode, the base station transmits a first selection instruction to the key thus causing the key to perform the subsequent communication in the active communications mode. If the reply signal of the key was received in the passive communications mode, the base station transmits a second selection instruction to the key thus causing the electronic key to perform the subsequent communication in the passive communications mode.