A method and a system for monitoring telephone calls are described. A
useful signal (which represents the call information of a telephone call)
and a data set (which contains at least one digital subscriber tag) are
supplied to a recording center (20). The data set is supplied to a
relaying device (28), in which it is compared with stored comparison data
sets. If the subscriber tag matches a corresponding comparison tag of a
selected comparison data set, a communications link is produced to a
monitoring device (36).
