A method for controlling features in a communication system having a first communication installation and a second communication installation, wherein the first and second communication installations (PBX1, PBX2) are connected via a computer telephony integration interface for controlling and monitoring the first communication installation, wherein (a) an item of feature control information input for a subscriber line of the first communication installation is transmitted to the first communication installation via a telephone connected to the first communication installation; (b) for analysis of the item of feature control information in the first communication installation it is verified whether a performance feature control instruction (C1,..., Cn) assigned to the item of feature control information is executable by the first communication installation, (c) after verification of the executability of a feature control instruction (C1,..., Cn) assigned to the item of feature control information in the first communication installation, the item of feature control information is only transmitted to the second communication installation in the event of non-executability via the CTI interface (d) the item of feature control information is converted by the second communication installation into at least one function call, the associated function of which is provided by the computer telephony integration interface, (e) the function call is transmitted to the first communication installation via the computer telephony integration interface, and where it is analyzed in an analysis unit with respect to feature control instructions (C1,..., Cn) contained in the function call or in the function call sequence, and (f) at least one feature control instruction (C1,..., Cn) contained in the function call and identified in the analysis unit is then transmitted to a administration and maintenance device of the first communication installation and executed by the same. (a) an item of feature control information input for a subscriber line of the first communication installation is transmitted to the first communication installation via a telephone connected to the first communication installation; (b) for analysis of the item of feature control information in the first communication installation it is verified whether a performance feature control instruction (C1,..., Cn) assigned to the item of feature control information is executable by the first communication installation, (c) after verification of the executability of a feature control instruction (C1,..., Cn) assigned to the item of feature control information in the first communication installation, the item of feature control information is only transmitted to the second communication installation in the event of non-executability via the CTI interface (d) the item of feature control information is converted by the second communication installation into at least one function call, the associated function of which is provided by the computer telephony integration interface, (e) the function call is transmitted to the first communication installation via the computer telephony integration interface, and where it is analyzed in an analysis unit with respect to feature control instructions (C1,..., Cn) contained in the function call or in the function call sequence, and (f) at least one feature control instruction (C1,..., Cn) contained in the function call and identified in the analysis unit is then transmitted to a administration and maintenance device of the first communication installation and executed by the same.