A first user device and second user device may be coupled, such as by an audio interface included in the second user device. The second user device is unable to generate a registration request, and the first user device may acquire device data associated with the second user device and form the registration request. The registration request may include the device data and information associated with the first user device. The registration request may be authenticated, and activation data may be generated based on the information associated with the first user device and the device data. The activation data is forwarded to the second user device to enable the second user device to access a restricted service or data.