1. A device, comprising:a processing system including a processor; and
a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising:
assigning a first international mobile subscriber identity (IMSI) to a first communication device;
assigning the first IMSI to a second communication device for a registration service area;
responsive to a first determination that the first communication device is not authorized to use the first IMSI in the registration service area, transmitting instructions to a first registration function server, wherein the instructions enable the second communication device to register in the registration service area with the first IMSI;
identifying a second registration function server in another registration service area, wherein a communication service area comprises the registration service area and the another registration service area; and
transmitting instructions to the second registration function server, wherein the instructions enable the first communication device to register in the another registration service area with the first IMSI.