Disclosed is a multi-SIM cellular telephone capable of accessing information on multiple SIM cards for multiple cellular service subscriptions while simultaneously accessing full functionality of all other features on the handset. It allows users to insert multiple SIM cards, each with a unique IMSI number associated with a unique cellular service subscription. The user can remove any SIM card and port to other handsets at his/her discretion. Purchasing extra cellular service for such purposes as business use is less expensive than was heretofore possible. Some services are only required on one subscription in order for the service to be used since the microprocessor assesses the features of each subscription and applies the required functionality to that SIM card. The multi-SIM cellular telephone also has a phone number that is associated with the handset; this number allows communication to and from the user of the multi-SIM phone on any installed subscription.