A T-Mobile customer who bought a new iPhone at an Apple store could not transfer her old phone there because the carrier had to handle the change. She drove to a T-Mobile location, where an employee found her account and completed the transfer. She left with her existing number, apps, photos and settings intact.
T-Mobile has decided to close a number of its stores, which may make that kind of in-person help harder for customers who need carrier-specific assistance. The experience also shows why a retail location can remain important even when a phone is purchased elsewhere: the Apple store supplied the device, but the T-Mobile store handled the wireless-service transition.