Depending on the country and ISP provider. NO need to jail break anything. I live in UK and have O2 contract. Tethering is a function of my IPhone and IOS (Iphone 3GS) . Most of the time I use WIFI, and if there is no WIFI I use 3G or 4G and tether my Ipad mini to my phone (set-up a Bluetooth connection between Ipad and Phone, then set-up hotspot and enable tethering on the phone, et voila) and in this case it will eat data from my contract.