Abstract: Systems and methods for using virtual subscriber identifiers in communication systems. An example method may comprise: receiving, by a processing device, a first subscriber identifier and a second subscriber identifier, wherein the first subscriber identifier identifies a subscriber of a first communication system; producing a third subscriber identifier based on the first subscriber identifier and the second subscriber identifier, wherein the third subscriber identifier identifies a subscriber of a second communication system; and causing a communication session to be established between the subscriber of the first communication system and the subscriber of the second communication system.