Methods and apparatus for activating a purchased or previously deployed device by a subscriber. In one embodiment, activation includes authenticating the device to a service provider or carrier, and providing the device with data necessary for enabling the service to the device. In one variant, a user device is activated at a retail store, with the assistance of a carrier representative. In another variant, user equipment is activated via a communications network without the assistance of a representative. In yet another variant, the user equipment is activated via the Internet without the assistance of a representative. The provision of access data includes pre-assigning eSIM from a population of unassigned eSIMs to certain devices for various carrier networks. Alternatively, the eSIM may be assigned on an as-needed basis. Unassigned and/or unused eSIMs can be released (or sold back to the vendor) and/or reused. Solutions for eSIM backup and restoration are also described.