US Mobile has two different SIM cards available for their customers to use. One SIM card operates on a CDMA network while the other works with the GSM network. Wisephone is only compatible with SIM cards that operate on the GSM network. (*see our carrier compatibility list here)
US Mobile CDMA SIM cards are colored Black/Blue.
> You will see NO SERVICE in the top left and an X in the top right over the service icon.
US Mobile GSM SIM cards are colored White.
> Service should be working, try restarting your device if you see an X.
*The colors on US Mobiles SIM cards could change..