A verification process is executed between a software-controlled communication device and a software-controlled server in a network to verify that an unconfirmed telephone number, which is transmitted to the server, corresponds to an actual subscription telephone number and that this subscription telephone number is assigned to the communication device. In the verification process, the server initiates a verification call to the unconfirmed telephone number from a selected calling telephone number. The communication device intercepts the verification call, identifies the originating telephone number, and transmits the originating telephone number to the server. The verification succeeds if the originating telephone number matches the calling telephone number.