I have recently switched my t-mobile plan to include wifi hotspot/tethering but am having trouble setting it up. I went under settings>more networks>mobile hotspot and tried to switch it from "off" to "on" and it said "mobile number not found". It may be worth noting that this phone is unlocked but was originally on the Verizon network so some verizon features (such as verizon cloud) are still on the phone.