I recently upgraded from an iPhone 5, and am now trying to sell that phone to recoup some of the cost... after calling Verizon to ensure the sim was unlocked and the esn clear, I found a buyer who wanted to purchase the phone to use on U.S. Cellular... I met him at the U.S. Cellular store last night and the rep there tried for hours to get the phone to connect to their network to no avail... what additional steps need to be taken to get this phone to work on other carriers? Thanks in advance!
To work on another carrier, that carrier has to use the same frequencies and bands as the Verizon Version of the iPhone 5. This includes the same CDMA frequencies and LTE bands. Some phones can work on some band and freq, but might not work with ALL bands and freq a carrier uses. This might limit the functionality of the device and also, there are all kinds of settings for a network that a person may have to manually set like APNs and such.
From US Cellular FAQ:
No, these devices are incompatible with the U.S. Cellular network. However, you can trade-in your existing iPhone for an iPhone that is compatible with the U.S. Cellular network. See your nearest U.S. Cellular store for trade-in program details.
Also I do not think US Cellular carried the iPhone because of incompatibility until the iPhone 5S and 5C