The sequence of steps a user must perform in order to unlock a cell phone depends on the original communications service provider and on the manufacturer of the phone set. Some cell phone sets can be unlocked by inputting codes to modify the software in the unit. Other sets require the purchase of special cables or modification of the internal hardware as well as reprogramming of the phone's data settings. In the wake of the U.S. Copyright Office's decision in November 2006 to allow cell-phone unlocking for at least three years thereafter, numerous companies began to offer unlocking services for a fee.
Proponents of cell-phone unlocking argue that consumers should be free to change their network when a subscription contract expires without having to discard hardware they purchased outright. Some cell-phone service providers, unhappy with the Copyright Office's decision, are resisting the practice by making their cell-phone sets difficult or impossible to unlock.