A method for assigning a piece of information (NAME) to address information (RUNO) on a first communications terminal (EG1, PC) of a communications system, wherein the communications system comprises a call distribution device in the form of an exchange system, a router or a gatekeeper, an exchange system database (PBXDB) and an additional database, coupled via a CTI application to the exchange system, in which data for communications terminals (EG1, PC) that are within the exchange system are stored, characterized in that in the additional database, data are stored in the form of an assignment table (ZTAB), which assigns the address information (RUNO) for communications terminals from outside the exchange to corresponding terminal-specific information (NAME), in which - when a connection is established between a second communications terminal and the first communications terminal (EG1, PC), the address information (RUNO) for the second communications terminal is detected in the first communications terminal (EG1, PC) or by the call distribution device of the communications system, - the call distribution device checks the address information (RUNO) to determine whether the second communications terminal is a communications terminal from within or outside of the communications system, - if the communications terminal (EG1, PC) is from within the communications system, the terminal-specific data are sent from the exchange system database (PBXDB) to the first communications terminal (EG1, PC), - if the communications terminal is from outside the communications system, the call distribution device establishes a query connection with the database and submits a query to the database via the query connection to search the assignment table (ZTAB) for an entry for the address information (RUNO), and - the entry for the address information (RUNO) is displayed on the first communications terminal (EG1, PC) such that the terminalspecific information (NAME) may be modified, or may be input if the assignment table (ZTAB) does not contain an entry for the address information (RUNO), and such that once this information (NAME) has been input or modified, it may be stored together with the address information (RUNO) in the assignment table (ZTAB). - when a connection is established between a second communications terminal and the first communications terminal (EG1, PC), the address information (RUNO) for the second communications terminal is detected in the first communications terminal (EG1, PC) or by the call distribution device of the communications system, - the call distribution device checks the address information (RUNO) to determine whether the second communications terminal is a communications terminal from within or outside of the communications system, - if the communications terminal (EG1, PC) is from within the communications system, the terminal-specific data are sent from the exchange system database (PBXDB) to the first communications terminal (EG1, PC), - if the communications terminal is from outside the communications system, the call distribution device establishes a query connection with the database and submits a query to the database via the query connection to search the assignment table (ZTAB) for an entry for the address information (RUNO), and - the entry for the address information (RUNO) is displayed on the first communications terminal (EG1, PC) such that the terminalspecific information (NAME) may be modified, or may be input if the assignment table (ZTAB) does not contain an entry for the address information (RUNO), and such that once this information (NAME) has been input or modified, it may be stored together with the address information (RUNO) in the assignment table (ZTAB).