The aim of the invention is to address short messages in a fixed network, both to fixed-network terminals that are operated as standalone units in the fixed network (3) or to terminals that are operated in parallel in said fixed network (3) and to extensions (10, 11, 12, 20, 21) of cord-connected or cordless fixed-network terminals (1, 2) that are configured as private branch exchanges and operated either as standalone units or in parallel in the fixed network (3). To achieve this, several numeric identifiers are assigned to each fixed-network terminal (1, 2) in order to address the short messages, in such a way that for a fixed network terminal (1, 2) that is configured as a private branch exchange, the numeric identifiers can be arbitrarily distributed among the extensions (10, 11, 12, 20, 21).